Merge branch 'linus' into sched/core

Conflicts:
	fs/proc/array.c

Merge reason: resolve conflict and queue up dependent patch.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

97 files changed, 8993 insertions, 8402 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 3d9c7e27e3f9..b8d4cd8ac0b9 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -58,7 +58,6 @@ obj-$(CONFIG_KEXEC) += kexec.o
 obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
 obj-$(CONFIG_COMPAT) += compat.o
 obj-$(CONFIG_CGROUPS) += cgroup.o
-obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o
 obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o
 obj-$(CONFIG_CPUSETS) += cpuset.o
 obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o
@@ -87,7 +86,6 @@ obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
-obj-$(CONFIG_MARKERS) += marker.o
 obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
 obj-$(CONFIG_LATENCYTOP) += latencytop.o
 obj-$(CONFIG_FUNCTION_TRACER) += trace/
@@ -96,7 +94,7 @@ obj-$(CONFIG_X86_DS) += trace/
 obj-$(CONFIG_RING_BUFFER) += trace/
 obj-$(CONFIG_SMP) += sched_cpupri.o
 obj-$(CONFIG_SLOW_WORK) += slow-work.o
-obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o
+obj-$(CONFIG_PERF_EVENTS) += perf_event.o
 
 ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/audit.c b/kernel/audit.c
index defc2e6f1e3b..5feed232be9d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -855,18 +855,24 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 break;
         }
         case AUDIT_SIGNAL_INFO:
-                err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
-                if (err)
-                        return err;
+                len = 0;
+                if (audit_sig_sid) {
+                        err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+                        if (err)
+                                return err;
+                }
                 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
                 if (!sig_data) {
-                        security_release_secctx(ctx, len);
+                        if (audit_sig_sid)
+                                security_release_secctx(ctx, len);
                         return -ENOMEM;
                 }
                 sig_data->uid = audit_sig_uid;
                 sig_data->pid = audit_sig_pid;
-                memcpy(sig_data->ctx, ctx, len);
-                security_release_secctx(ctx, len);
+                if (audit_sig_sid) {
+                        memcpy(sig_data->ctx, ctx, len);
+                        security_release_secctx(ctx, len);
+                }
                 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
                                 0, 0, sig_data, sizeof(*sig_data) + len);
                 kfree(sig_data);
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 0e96dbc60ea9..cc7e87936cbc 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -45,8 +45,8 @@
 
 struct audit_watch {
         atomic_t                count;  /* reference count */
-        char                    *path;  /* insertion path */
         dev_t                   dev;    /* associated superblock device */
+        char                    *path;  /* insertion path */
         unsigned long           ino;    /* associated inode number */
         struct audit_parent     *parent; /* associated parent */
         struct list_head        wlist;  /* entry in parent->watches list */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 68d3c6a0ecd6..267e484f0198 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -168,12 +168,12 @@ struct audit_context {
         int                 in_syscall; /* 1 if task is in a syscall */
         enum audit_state    state, current_state;
         unsigned int        serial;     /* serial number for record */
-        struct timespec     ctime;      /* time of syscall entry */
         int                 major;      /* syscall number */
+        struct timespec     ctime;      /* time of syscall entry */
         unsigned long       argv[4];    /* syscall arguments */
-        int                 return_valid; /* return code is valid */
         long                return_code;/* syscall return code */
         u64                 prio;
+        int                 return_valid; /* return code is valid */
         int                 name_count;
         struct audit_names  names[AUDIT_NAMES];
         char *              filterkey;  /* key for rule that triggered record */
@@ -198,8 +198,8 @@ struct audit_context {
         char                target_comm[TASK_COMM_LEN];
 
         struct audit_tree_refs *trees, *first_trees;
-        int tree_count;
         struct list_head killed_trees;
+        int tree_count;
 
         int type;
         union {
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index c7ece8f027f2..ca83b73fba19 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -23,6 +23,7 @@
  */
 
 #include <linux/cgroup.h>
+#include <linux/ctype.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
@@ -48,6 +49,8 @@
 #include <linux/namei.h>
 #include <linux/smp_lock.h>
 #include <linux/pid_namespace.h>
+#include <linux/idr.h>
+#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
 
 #include <asm/atomic.h>
 
@@ -60,6 +63,8 @@ static struct cgroup_subsys *subsys[] = {
 #include <linux/cgroup_subsys.h>
 };
 
+#define MAX_CGROUP_ROOT_NAMELEN 64
+
 /*
  * A cgroupfs_root represents the root of a cgroup hierarchy,
  * and may be associated with a superblock to form an active
@@ -74,6 +79,9 @@ struct cgroupfs_root {
          */
         unsigned long subsys_bits;
 
+        /* Unique id for this hierarchy. */
+        int hierarchy_id;
+
         /* The bitmask of subsystems currently attached to this hierarchy */
         unsigned long actual_subsys_bits;
 
@@ -94,6 +102,9 @@ struct cgroupfs_root {
 
         /* The path to use for release notifications. */
         char release_agent_path[PATH_MAX];
+
+        /* The name for this hierarchy - may be empty */
+        char name[MAX_CGROUP_ROOT_NAMELEN];
 };
 
 /*
@@ -141,6 +152,10 @@ struct css_id {
 static LIST_HEAD(roots);
 static int root_count;
 
+static DEFINE_IDA(hierarchy_ida);
+static int next_hierarchy_id;
+static DEFINE_SPINLOCK(hierarchy_id_lock);
+
 /* dummytop is a shorthand for the dummy hierarchy's top cgroup */
 #define dummytop (&rootnode.top_cgroup)
 
@@ -201,6 +216,7 @@ struct cg_cgroup_link {
          * cgroup, anchored on cgroup->css_sets
          */
         struct list_head cgrp_link_list;
+        struct cgroup *cgrp;
         /*
          * List running through cg_cgroup_links pointing at a
          * single css_set object, anchored on css_set->cg_links
@@ -227,8 +243,11 @@ static int cgroup_subsys_init_idr(struct cgroup_subsys *ss);
 static DEFINE_RWLOCK(css_set_lock);
 static int css_set_count;
 
-/* hash table for cgroup groups. This improves the performance to
- * find an existing css_set */
+/*
+ * hash table for cgroup groups. This improves the performance to find
+ * an existing css_set. This hash doesn't (currently) take into
+ * account cgroups in empty hierarchies.
+ */
 #define CSS_SET_HASH_BITS       7
 #define CSS_SET_TABLE_SIZE      (1 << CSS_SET_HASH_BITS)
 static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE];
@@ -248,48 +267,22 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[])
         return &css_set_table[index];
 }
 
+static void free_css_set_rcu(struct rcu_head *obj)
+{
+        struct css_set *cg = container_of(obj, struct css_set, rcu_head);
+        kfree(cg);
+}
+
 /* We don't maintain the lists running through each css_set to its
  * task until after the first call to cgroup_iter_start(). This
  * reduces the fork()/exit() overhead for people who have cgroups
  * compiled into their kernel but not actually in use */
 static int use_task_css_set_links __read_mostly;
 
-/* When we create or destroy a css_set, the operation simply
- * takes/releases a reference count on all the cgroups referenced
- * by subsystems in this css_set. This can end up multiple-counting
- * some cgroups, but that's OK - the ref-count is just a
- * busy/not-busy indicator; ensuring that we only count each cgroup
- * once would require taking a global lock to ensure that no
- * subsystems moved between hierarchies while we were doing so.
- *
- * Possible TODO: decide at boot time based on the number of
- * registered subsystems and the number of CPUs or NUMA nodes whether
- * it's better for performance to ref-count every subsystem, or to
- * take a global lock and only add one ref count to each hierarchy.
- */
-
-/*
- * unlink a css_set from the list and free it
- */
-static void unlink_css_set(struct css_set *cg)
+static void __put_css_set(struct css_set *cg, int taskexit)
 {
         struct cg_cgroup_link *link;
         struct cg_cgroup_link *saved_link;
-
-        hlist_del(&cg->hlist);
-        css_set_count--;
-
-        list_for_each_entry_safe(link, saved_link, &cg->cg_links,
-                                 cg_link_list) {
-                list_del(&link->cg_link_list);
-                list_del(&link->cgrp_link_list);
-                kfree(link);
-        }
-}
-
-static void __put_css_set(struct css_set *cg, int taskexit)
-{
-        int i;
         /*
          * Ensure that the refcount doesn't hit zero while any readers
          * can see it. Similar to atomic_dec_and_lock(), but for an
@@ -302,21 +295,28 @@ static void __put_css_set(struct css_set *cg, int taskexit)
                 write_unlock(&css_set_lock);
                 return;
         }
-        unlink_css_set(cg);
-        write_unlock(&css_set_lock);
 
-        rcu_read_lock();
-        for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-                struct cgroup *cgrp = rcu_dereference(cg->subsys[i]->cgroup);
+        /* This css_set is dead. unlink it and release cgroup refcounts */
+        hlist_del(&cg->hlist);
+        css_set_count--;
+
+        list_for_each_entry_safe(link, saved_link, &cg->cg_links,
+                                 cg_link_list) {
+                struct cgroup *cgrp = link->cgrp;
+                list_del(&link->cg_link_list);
+                list_del(&link->cgrp_link_list);
                 if (atomic_dec_and_test(&cgrp->count) &&
                     notify_on_release(cgrp)) {
                         if (taskexit)
                                 set_bit(CGRP_RELEASABLE, &cgrp->flags);
                         check_for_release(cgrp);
                 }
+
+                kfree(link);
         }
-        rcu_read_unlock();
-        kfree(cg);
+
+        write_unlock(&css_set_lock);
+        call_rcu(&cg->rcu_head, free_css_set_rcu);
 }
 
 /*
@@ -338,6 +338,78 @@ static inline void put_css_set_taskexit(struct css_set *cg)
 }
 
 /*
+ * compare_css_sets - helper function for find_existing_css_set().
+ * @cg: candidate css_set being tested
+ * @old_cg: existing css_set for a task
+ * @new_cgrp: cgroup that's being entered by the task
+ * @template: desired set of css pointers in css_set (pre-calculated)
+ *
+ * Returns true if "cg" matches "old_cg" except for the hierarchy
+ * which "new_cgrp" belongs to, for which it should match "new_cgrp".
+ */
+static bool compare_css_sets(struct css_set *cg,
+                             struct css_set *old_cg,
+                             struct cgroup *new_cgrp,
+                             struct cgroup_subsys_state *template[])
+{
+        struct list_head *l1, *l2;
+
+        if (memcmp(template, cg->subsys, sizeof(cg->subsys))) {
+                /* Not all subsystems matched */
+                return false;
+        }
+
+        /*
+         * Compare cgroup pointers in order to distinguish between
+         * different cgroups in heirarchies with no subsystems. We
+         * could get by with just this check alone (and skip the
+         * memcmp above) but on most setups the memcmp check will
+         * avoid the need for this more expensive check on almost all
+         * candidates.
+         */
+
+        l1 = &cg->cg_links;
+        l2 = &old_cg->cg_links;
+        while (1) {
+                struct cg_cgroup_link *cgl1, *cgl2;
+                struct cgroup *cg1, *cg2;
+
+                l1 = l1->next;
+                l2 = l2->next;
+                /* See if we reached the end - both lists are equal length. */
+                if (l1 == &cg->cg_links) {
+                        BUG_ON(l2 != &old_cg->cg_links);
+                        break;
+                } else {
+                        BUG_ON(l2 == &old_cg->cg_links);
+                }
+                /* Locate the cgroups associated with these links. */
+                cgl1 = list_entry(l1, struct cg_cgroup_link, cg_link_list);
+                cgl2 = list_entry(l2, struct cg_cgroup_link, cg_link_list);
+                cg1 = cgl1->cgrp;
+                cg2 = cgl2->cgrp;
+                /* Hierarchies should be linked in the same order. */
+                BUG_ON(cg1->root != cg2->root);
+
+                /*
+                 * If this hierarchy is the hierarchy of the cgroup
+                 * that's changing, then we need to check that this
+                 * css_set points to the new cgroup; if it's any other
+                 * hierarchy, then this css_set should point to the
+                 * same cgroup as the old css_set.
+                 */
+                if (cg1->root == new_cgrp->root) {
+                        if (cg1 != new_cgrp)
+                                return false;
+                } else {
+                        if (cg1 != cg2)
+                                return false;
+                }
+        }
+        return true;
+}
+
+/*
  * find_existing_css_set() is a helper for
  * find_css_set(), and checks to see whether an existing
  * css_set is suitable.
@@ -378,10 +450,11 @@ static struct css_set *find_existing_css_set(
 
         hhead = css_set_hash(template);
         hlist_for_each_entry(cg, node, hhead, hlist) {
-                if (!memcmp(template, cg->subsys, sizeof(cg->subsys))) {
-                        /* All subsystems matched */
-                        return cg;
-                }
+                if (!compare_css_sets(cg, oldcg, cgrp, template))
+                        continue;
+
+                /* This css_set matches what we need */
+                return cg;
         }
 
         /* No existing cgroup group matched */
@@ -435,8 +508,14 @@ static void link_css_set(struct list_head *tmp_cg_links,
         link = list_first_entry(tmp_cg_links, struct cg_cgroup_link,
                                 cgrp_link_list);
         link->cg = cg;
+        link->cgrp = cgrp;
+        atomic_inc(&cgrp->count);
         list_move(&link->cgrp_link_list, &cgrp->css_sets);
-        list_add(&link->cg_link_list, &cg->cg_links);
+        /*
+         * Always add links to the tail of the list so that the list
+         * is sorted by order of hierarchy creation
+         */
+        list_add_tail(&link->cg_link_list, &cg->cg_links);
 }
 
 /*
@@ -451,11 +530,11 @@ static struct css_set *find_css_set(
 {
         struct css_set *res;
         struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT];
-        int i;
 
         struct list_head tmp_cg_links;
 
         struct hlist_head *hhead;
+        struct cg_cgroup_link *link;
 
         /* First see if we already have a cgroup group that matches
          * the desired set */
@@ -489,20 +568,12 @@ static struct css_set *find_css_set(
 
         write_lock(&css_set_lock);
         /* Add reference counts and links from the new css_set. */
-        for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-                struct cgroup *cgrp = res->subsys[i]->cgroup;
-                struct cgroup_subsys *ss = subsys[i];
-                atomic_inc(&cgrp->count);
-                /*
-                 * We want to add a link once per cgroup, so we
-                 * only do it for the first subsystem in each
-                 * hierarchy
-                 */
-                if (ss->root->subsys_list.next == &ss->sibling)
-                        link_css_set(&tmp_cg_links, res, cgrp);
+        list_for_each_entry(link, &oldcg->cg_links, cg_link_list) {
+                struct cgroup *c = link->cgrp;
+                if (c->root == cgrp->root)
+                        c = cgrp;
+                link_css_set(&tmp_cg_links, res, c);
         }
-        if (list_empty(&rootnode.subsys_list))
-                link_css_set(&tmp_cg_links, res, dummytop);
 
         BUG_ON(!list_empty(&tmp_cg_links));
 
@@ -518,6 +589,41 @@ static struct css_set *find_css_set(
 }
 
 /*
+ * Return the cgroup for "task" from the given hierarchy. Must be
+ * called with cgroup_mutex held.
+ */
+static struct cgroup *task_cgroup_from_root(struct task_struct *task,
+                                            struct cgroupfs_root *root)
+{
+        struct css_set *css;
+        struct cgroup *res = NULL;
+
+        BUG_ON(!mutex_is_locked(&cgroup_mutex));
+        read_lock(&css_set_lock);
+        /*
+         * No need to lock the task - since we hold cgroup_mutex the
+         * task can't change groups, so the only thing that can happen
+         * is that it exits and its css is set back to init_css_set.
+         */
+        css = task->cgroups;
+        if (css == &init_css_set) {
+                res = &root->top_cgroup;
+        } else {
+                struct cg_cgroup_link *link;
+                list_for_each_entry(link, &css->cg_links, cg_link_list) {
+                        struct cgroup *c = link->cgrp;
+                        if (c->root == root) {
+                                res = c;
+                                break;
+                        }
+                }
+        }
+        read_unlock(&css_set_lock);
+        BUG_ON(!res);
+        return res;
+}
+
+/*
  * There is one global cgroup mutex. We also require taking
  * task_lock() when dereferencing a task's cgroup subsys pointers.
  * See "The task_lock() exception", at the end of this comment.
@@ -596,8 +702,8 @@ void cgroup_unlock(void)
 static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode);
 static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry);
 static int cgroup_populate_dir(struct cgroup *cgrp);
-static struct inode_operations cgroup_dir_inode_operations;
-static struct file_operations proc_cgroupstats_operations;
+static const struct inode_operations cgroup_dir_inode_operations;
+static const struct file_operations proc_cgroupstats_operations;
 
 static struct backing_dev_info cgroup_backing_dev_info = {
         .name           = "cgroup",
@@ -677,6 +783,12 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
                  */
                 deactivate_super(cgrp->root->sb);
 
+                /*
+                 * if we're getting rid of the cgroup, refcount should ensure
+                 * that there are no pidlists left.
+                 */
+                BUG_ON(!list_empty(&cgrp->pidlists));
+
                 call_rcu(&cgrp->rcu_head, free_cgroup_rcu);
         }
         iput(inode);
@@ -841,6 +953,8 @@ static int cgroup_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_puts(seq, ",noprefix");
         if (strlen(root->release_agent_path))
                 seq_printf(seq, ",release_agent=%s", root->release_agent_path);
+        if (strlen(root->name))
+                seq_printf(seq, ",name=%s", root->name);
         mutex_unlock(&cgroup_mutex);
         return 0;
 }
@@ -849,6 +963,12 @@ struct cgroup_sb_opts {
         unsigned long subsys_bits;
         unsigned long flags;
         char *release_agent;
+        char *name;
+        /* User explicitly requested empty subsystem */
+        bool none;
+
+        struct cgroupfs_root *new_root;
+
 };
 
 /* Convert a hierarchy specifier into a bitmask of subsystems and
@@ -863,9 +983,7 @@ static int parse_cgroupfs_options(char *data,
         mask = ~(1UL << cpuset_subsys_id);
 #endif
 
-        opts->subsys_bits = 0;
-        opts->flags = 0;
-        opts->release_agent = NULL;
+        memset(opts, 0, sizeof(*opts));
 
         while ((token = strsep(&o, ",")) != NULL) {
                 if (!*token)
@@ -879,17 +997,42 @@ static int parse_cgroupfs_options(char *data,
                                 if (!ss->disabled)
                                         opts->subsys_bits |= 1ul << i;
                         }
+                } else if (!strcmp(token, "none")) {
+                        /* Explicitly have no subsystems */
+                        opts->none = true;
                 } else if (!strcmp(token, "noprefix")) {
                         set_bit(ROOT_NOPREFIX, &opts->flags);
                 } else if (!strncmp(token, "release_agent=", 14)) {
                         /* Specifying two release agents is forbidden */
                         if (opts->release_agent)
                                 return -EINVAL;
-                        opts->release_agent = kzalloc(PATH_MAX, GFP_KERNEL);
+                        opts->release_agent =
+                                kstrndup(token + 14, PATH_MAX, GFP_KERNEL);
                         if (!opts->release_agent)
                                 return -ENOMEM;
-                        strncpy(opts->release_agent, token + 14, PATH_MAX - 1);
-                        opts->release_agent[PATH_MAX - 1] = 0;
+                } else if (!strncmp(token, "name=", 5)) {
+                        int i;
+                        const char *name = token + 5;
+                        /* Can't specify an empty name */
+                        if (!strlen(name))
+                                return -EINVAL;
+                        /* Must match [\w.-]+ */
+                        for (i = 0; i < strlen(name); i++) {
+                                char c = name[i];
+                                if (isalnum(c))
+                                        continue;
+                                if ((c == '.') || (c == '-') || (c == '_'))
+                                        continue;
+                                return -EINVAL;
+                        }
+                        /* Specifying two names is forbidden */
+                        if (opts->name)
+                                return -EINVAL;
+                        opts->name = kstrndup(name,
+                                              MAX_CGROUP_ROOT_NAMELEN,
+                                              GFP_KERNEL);
+                        if (!opts->name)
+                                return -ENOMEM;
                 } else {
                         struct cgroup_subsys *ss;
                         int i;
@@ -906,6 +1049,8 @@ static int parse_cgroupfs_options(char *data,
                 }
         }
 
+        /* Consistency checks */
+
         /*
          * Option noprefix was introduced just for backward compatibility
          * with the old cpuset, so we allow noprefix only if mounting just
@@ -915,8 +1060,16 @@ static int parse_cgroupfs_options(char *data,
             (opts->subsys_bits & mask))
                 return -EINVAL;
 
-        /* We can't have an empty hierarchy */
-        if (!opts->subsys_bits)
+
+        /* Can't specify "none" and some subsystems */
+        if (opts->subsys_bits && opts->none)
+                return -EINVAL;
+
+        /*
+         * We either have to specify by name or by subsystems. (So all
+         * empty hierarchies must have a name).
+         */
+        if (!opts->subsys_bits && !opts->name)
                 return -EINVAL;
 
         return 0;
@@ -944,6 +1097,12 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
                 goto out_unlock;
         }
 
+        /* Don't allow name to change at remount */
+        if (opts.name && strcmp(opts.name, root->name)) {
+                ret = -EINVAL;
+                goto out_unlock;
+        }
+
         ret = rebind_subsystems(root, opts.subsys_bits);
         if (ret)
                 goto out_unlock;
@@ -955,13 +1114,14 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
                 strcpy(root->release_agent_path, opts.release_agent);
  out_unlock:
         kfree(opts.release_agent);
+        kfree(opts.name);
         mutex_unlock(&cgroup_mutex);
         mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
         unlock_kernel();
         return ret;
 }
 
-static struct super_operations cgroup_ops = {
+static const struct super_operations cgroup_ops = {
         .statfs = simple_statfs,
         .drop_inode = generic_delete_inode,
         .show_options = cgroup_show_options,
@@ -974,9 +1134,10 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
         INIT_LIST_HEAD(&cgrp->children);
         INIT_LIST_HEAD(&cgrp->css_sets);
         INIT_LIST_HEAD(&cgrp->release_list);
-        INIT_LIST_HEAD(&cgrp->pids_list);
-        init_rwsem(&cgrp->pids_mutex);
+        INIT_LIST_HEAD(&cgrp->pidlists);
+        mutex_init(&cgrp->pidlist_mutex);
 }
+
 static void init_cgroup_root(struct cgroupfs_root *root)
 {
         struct cgroup *cgrp = &root->top_cgroup;
@@ -988,33 +1149,106 @@ static void init_cgroup_root(struct cgroupfs_root *root)
         init_cgroup_housekeeping(cgrp);
 }
 
+static bool init_root_id(struct cgroupfs_root *root)
+{
+        int ret = 0;
+
+        do {
+                if (!ida_pre_get(&hierarchy_ida, GFP_KERNEL))
+                        return false;
+                spin_lock(&hierarchy_id_lock);
+                /* Try to allocate the next unused ID */
+                ret = ida_get_new_above(&hierarchy_ida, next_hierarchy_id,
+                                        &root->hierarchy_id);
+                if (ret == -ENOSPC)
+                        /* Try again starting from 0 */
+                        ret = ida_get_new(&hierarchy_ida, &root->hierarchy_id);
+                if (!ret) {
+                        next_hierarchy_id = root->hierarchy_id + 1;
+                } else if (ret != -EAGAIN) {
+                        /* Can only get here if the 31-bit IDR is full ... */
+                        BUG_ON(ret);
+                }
+                spin_unlock(&hierarchy_id_lock);
+        } while (ret);
+        return true;
+}
+
 static int cgroup_test_super(struct super_block *sb, void *data)
 {
-        struct cgroupfs_root *new = data;
+        struct cgroup_sb_opts *opts = data;
         struct cgroupfs_root *root = sb->s_fs_info;
 
-        /* First check subsystems */
-        if (new->subsys_bits != root->subsys_bits)
-            return 0;
+        /* If we asked for a name then it must match */
+        if (opts->name && strcmp(opts->name, root->name))
+                return 0;
 
-        /* Next check flags */
-        if (new->flags != root->flags)
+        /*
+         * If we asked for subsystems (or explicitly for no
+         * subsystems) then they must match
+         */
+        if ((opts->subsys_bits || opts->none)
+            && (opts->subsys_bits != root->subsys_bits))
                 return 0;
 
         return 1;
 }
 
+static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
+{
+        struct cgroupfs_root *root;
+
+        if (!opts->subsys_bits && !opts->none)
+                return NULL;
+
+        root = kzalloc(sizeof(*root), GFP_KERNEL);
+        if (!root)
+                return ERR_PTR(-ENOMEM);
+
+        if (!init_root_id(root)) {
+                kfree(root);
+                return ERR_PTR(-ENOMEM);
+        }
+        init_cgroup_root(root);
+
+        root->subsys_bits = opts->subsys_bits;
+        root->flags = opts->flags;
+        if (opts->release_agent)
+                strcpy(root->release_agent_path, opts->release_agent);
+        if (opts->name)
+                strcpy(root->name, opts->name);
+        return root;
+}
+
+static void cgroup_drop_root(struct cgroupfs_root *root)
+{
+        if (!root)
+                return;
+
+        BUG_ON(!root->hierarchy_id);
+        spin_lock(&hierarchy_id_lock);
+        ida_remove(&hierarchy_ida, root->hierarchy_id);
+        spin_unlock(&hierarchy_id_lock);
+        kfree(root);
+}
+
 static int cgroup_set_super(struct super_block *sb, void *data)
 {
         int ret;
-        struct cgroupfs_root *root = data;
+        struct cgroup_sb_opts *opts = data;
+
+        /* If we don't have a new root, we can't set up a new sb */
+        if (!opts->new_root)
+                return -EINVAL;
+
+        BUG_ON(!opts->subsys_bits && !opts->none);
 
         ret = set_anon_super(sb, NULL);
         if (ret)
                 return ret;
 
-        sb->s_fs_info = root;
-        root->sb = sb;
+        sb->s_fs_info = opts->new_root;
+        opts->new_root->sb = sb;
 
         sb->s_blocksize = PAGE_CACHE_SIZE;
         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
@@ -1051,48 +1285,43 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
                          void *data, struct vfsmount *mnt)
 {
         struct cgroup_sb_opts opts;
+        struct cgroupfs_root *root;
         int ret = 0;
         struct super_block *sb;
-        struct cgroupfs_root *root;
-        struct list_head tmp_cg_links;
+        struct cgroupfs_root *new_root;
 
         /* First find the desired set of subsystems */
         ret = parse_cgroupfs_options(data, &opts);
-        if (ret) {
-                kfree(opts.release_agent);
-                return ret;
-        }
-
-        root = kzalloc(sizeof(*root), GFP_KERNEL);
-        if (!root) {
-                kfree(opts.release_agent);
-                return -ENOMEM;
-        }
+        if (ret)
+                goto out_err;
 
-        init_cgroup_root(root);
-        root->subsys_bits = opts.subsys_bits;
-        root->flags = opts.flags;
-        if (opts.release_agent) {
-                strcpy(root->release_agent_path, opts.release_agent);
-                kfree(opts.release_agent);
+        /*
+         * Allocate a new cgroup root. We may not need it if we're
+         * reusing an existing hierarchy.
+         */
+        new_root = cgroup_root_from_opts(&opts);
+        if (IS_ERR(new_root)) {
+                ret = PTR_ERR(new_root);
+                goto out_err;
         }
+        opts.new_root = new_root;
 
-        sb = sget(fs_type, cgroup_test_super, cgroup_set_super, root);
-
+        /* Locate an existing or new sb for this hierarchy */
+        sb = sget(fs_type, cgroup_test_super, cgroup_set_super, &opts);
         if (IS_ERR(sb)) {
-                kfree(root);
-                return PTR_ERR(sb);
+                ret = PTR_ERR(sb);
+                cgroup_drop_root(opts.new_root);
+                goto out_err;
         }
 
-        if (sb->s_fs_info != root) {
-                /* Reusing an existing superblock */
-                BUG_ON(sb->s_root == NULL);
-                kfree(root);
-                root = NULL;
-        } else {
-                /* New superblock */
+        root = sb->s_fs_info;
+        BUG_ON(!root);
+        if (root == opts.new_root) {
+                /* We used the new root structure, so this is a new hierarchy */
+                struct list_head tmp_cg_links;
                 struct cgroup *root_cgrp = &root->top_cgroup;
                 struct inode *inode;
+                struct cgroupfs_root *existing_root;
                 int i;
 
                 BUG_ON(sb->s_root != NULL);
@@ -1105,6 +1334,18 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
                 mutex_lock(&inode->i_mutex);
                 mutex_lock(&cgroup_mutex);
 
+                if (strlen(root->name)) {
+                        /* Check for name clashes with existing mounts */
+                        for_each_active_root(existing_root) {
+                                if (!strcmp(existing_root->name, root->name)) {
+                                        ret = -EBUSY;
+                                        mutex_unlock(&cgroup_mutex);
+                                        mutex_unlock(&inode->i_mutex);
+                                        goto drop_new_super;
+                                }
+                        }
+                }
+
                 /*
                  * We're accessing css_set_count without locking
                  * css_set_lock here, but that's OK - it can only be
@@ -1123,7 +1364,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
                 if (ret == -EBUSY) {
                         mutex_unlock(&cgroup_mutex);
                         mutex_unlock(&inode->i_mutex);
-                        goto free_cg_links;
+                        free_cg_links(&tmp_cg_links);
+                        goto drop_new_super;
                 }
 
                 /* EBUSY should be the only error here */
@@ -1155,17 +1397,27 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
                 BUG_ON(root->number_of_cgroups != 1);
 
                 cgroup_populate_dir(root_cgrp);
-                mutex_unlock(&inode->i_mutex);
                 mutex_unlock(&cgroup_mutex);
+                mutex_unlock(&inode->i_mutex);
+        } else {
+                /*
+                 * We re-used an existing hierarchy - the new root (if
+                 * any) is not needed
+                 */
+                cgroup_drop_root(opts.new_root);
         }
 
         simple_set_mnt(mnt, sb);
+        kfree(opts.release_agent);
+        kfree(opts.name);
         return 0;
 
- free_cg_links:
-        free_cg_links(&tmp_cg_links);
  drop_new_super:
         deactivate_locked_super(sb);
+ out_err:
+        kfree(opts.release_agent);
+        kfree(opts.name);
+
         return ret;
 }
 
@@ -1211,7 +1463,7 @@ static void cgroup_kill_sb(struct super_block *sb) {
         mutex_unlock(&cgroup_mutex);
 
         kill_litter_super(sb);
-        kfree(root);
+        cgroup_drop_root(root);
 }
 
 static struct file_system_type cgroup_fs_type = {
@@ -1276,27 +1528,6 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
         return 0;
 }
 
-/*
- * Return the first subsystem attached to a cgroup's hierarchy, and
- * its subsystem id.
- */
-
-static void get_first_subsys(const struct cgroup *cgrp,
-                        struct cgroup_subsys_state **css, int *subsys_id)
-{
-        const struct cgroupfs_root *root = cgrp->root;
-        const struct cgroup_subsys *test_ss;
-        BUG_ON(list_empty(&root->subsys_list));
-        test_ss = list_entry(root->subsys_list.next,
-                             struct cgroup_subsys, sibling);
-        if (css) {
-                *css = cgrp->subsys[test_ss->subsys_id];
-                BUG_ON(!*css);
-        }
-        if (subsys_id)
-                *subsys_id = test_ss->subsys_id;
-}
-
 /**
  * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp'
  * @cgrp: the cgroup the task is attaching to
@@ -1313,18 +1544,15 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
         struct css_set *cg;
         struct css_set *newcg;
         struct cgroupfs_root *root = cgrp->root;
-        int subsys_id;
-
-        get_first_subsys(cgrp, NULL, &subsys_id);
 
         /* Nothing to do if the task is already in that cgroup */
-        oldcgrp = task_cgroup(tsk, subsys_id);
+        oldcgrp = task_cgroup_from_root(tsk, root);
         if (cgrp == oldcgrp)
                 return 0;
 
         for_each_subsys(root, ss) {
                 if (ss->can_attach) {
-                        retval = ss->can_attach(ss, cgrp, tsk);
+                        retval = ss->can_attach(ss, cgrp, tsk, false);
                         if (retval)
                                 return retval;
                 }
@@ -1362,7 +1590,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 
         for_each_subsys(root, ss) {
                 if (ss->attach)
-                        ss->attach(ss, cgrp, oldcgrp, tsk);
+                        ss->attach(ss, cgrp, oldcgrp, tsk, false);
         }
         set_bit(CGRP_RELEASABLE, &oldcgrp->flags);
         synchronize_rcu();
@@ -1423,15 +1651,6 @@ static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid)
         return ret;
 }
 
-/* The various types of files and directories in a cgroup file system */
-enum cgroup_filetype {
-        FILE_ROOT,
-        FILE_DIR,
-        FILE_TASKLIST,
-        FILE_NOTIFY_ON_RELEASE,
-        FILE_RELEASE_AGENT,
-};
-
 /**
  * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive.
  * @cgrp: the cgroup to be checked for liveness
@@ -1644,7 +1863,7 @@ static int cgroup_seqfile_release(struct inode *inode, struct file *file)
         return single_release(inode, file);
 }
 
-static struct file_operations cgroup_seqfile_operations = {
+static const struct file_operations cgroup_seqfile_operations = {
         .read = seq_read,
         .write = cgroup_file_write,
         .llseek = seq_lseek,
@@ -1703,7 +1922,7 @@ static int cgroup_rename(struct inode *old_dir, struct dentry *old_dentry,
         return simple_rename(old_dir, old_dentry, new_dir, new_dentry);
 }
 
-static struct file_operations cgroup_file_operations = {
+static const struct file_operations cgroup_file_operations = {
         .read = cgroup_file_read,
         .write = cgroup_file_write,
         .llseek = generic_file_llseek,
@@ -1711,7 +1930,7 @@ static struct file_operations cgroup_file_operations = {
         .release = cgroup_file_release,
 };
 
-static struct inode_operations cgroup_dir_inode_operations = {
+static const struct inode_operations cgroup_dir_inode_operations = {
         .lookup = simple_lookup,
         .mkdir = cgroup_mkdir,
         .rmdir = cgroup_rmdir,
@@ -1876,7 +2095,7 @@ int cgroup_task_count(const struct cgroup *cgrp)
  * the start of a css_set
  */
 static void cgroup_advance_iter(struct cgroup *cgrp,
-                                          struct cgroup_iter *it)
+                                struct cgroup_iter *it)
 {
         struct list_head *l = it->cg_link;
         struct cg_cgroup_link *link;
@@ -2129,7 +2348,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
 }
 
 /*
- * Stuff for reading the 'tasks' file.
+ * Stuff for reading the 'tasks'/'procs' files.
  *
  * Reading this file can return large amounts of data if a cgroup has
  * *lots* of attached tasks. So it may need several calls to read(),
@@ -2139,27 +2358,196 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
  */
 
 /*
- * Load into 'pidarray' up to 'npids' of the tasks using cgroup
- * 'cgrp'.  Return actual number of pids loaded.  No need to
- * task_lock(p) when reading out p->cgroup, since we're in an RCU
- * read section, so the css_set can't go away, and is
- * immutable after creation.
+ * The following two functions "fix" the issue where there are more pids
+ * than kmalloc will give memory for; in such cases, we use vmalloc/vfree.
+ * TODO: replace with a kernel-wide solution to this problem
+ */
+#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
+static void *pidlist_allocate(int count)
+{
+        if (PIDLIST_TOO_LARGE(count))
+                return vmalloc(count * sizeof(pid_t));
+        else
+                return kmalloc(count * sizeof(pid_t), GFP_KERNEL);
+}
+static void pidlist_free(void *p)
+{
+        if (is_vmalloc_addr(p))
+                vfree(p);
+        else
+                kfree(p);
+}
+static void *pidlist_resize(void *p, int newcount)
+{
+        void *newlist;
+        /* note: if new alloc fails, old p will still be valid either way */
+        if (is_vmalloc_addr(p)) {
+                newlist = vmalloc(newcount * sizeof(pid_t));
+                if (!newlist)
+                        return NULL;
+                memcpy(newlist, p, newcount * sizeof(pid_t));
+                vfree(p);
+        } else {
+                newlist = krealloc(p, newcount * sizeof(pid_t), GFP_KERNEL);
+        }
+        return newlist;
+}
+
+/*
+ * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries
+ * If the new stripped list is sufficiently smaller and there's enough memory
+ * to allocate a new buffer, will let go of the unneeded memory. Returns the
+ * number of unique elements.
+ */
+/* is the size difference enough that we should re-allocate the array? */
+#define PIDLIST_REALLOC_DIFFERENCE(old, new) ((old) - PAGE_SIZE >= (new))
+static int pidlist_uniq(pid_t **p, int length)
+{
+        int src, dest = 1;
+        pid_t *list = *p;
+        pid_t *newlist;
+
+        /*
+         * we presume the 0th element is unique, so i starts at 1. trivial
+         * edge cases first; no work needs to be done for either
+         */
+        if (length == 0 || length == 1)
+                return length;
+        /* src and dest walk down the list; dest counts unique elements */
+        for (src = 1; src < length; src++) {
+                /* find next unique element */
+                while (list[src] == list[src-1]) {
+                        src++;
+                        if (src == length)
+                                goto after;
+                }
+                /* dest always points to where the next unique element goes */
+                list[dest] = list[src];
+                dest++;
+        }
+after:
+        /*
+         * if the length difference is large enough, we want to allocate a
+         * smaller buffer to save memory. if this fails due to out of memory,
+         * we'll just stay with what we've got.
+         */
+        if (PIDLIST_REALLOC_DIFFERENCE(length, dest)) {
+                newlist = pidlist_resize(list, dest);
+                if (newlist)
+                        *p = newlist;
+        }
+        return dest;
+}
+
+static int cmppid(const void *a, const void *b)
+{
+        return *(pid_t *)a - *(pid_t *)b;
+}
+
+/*
+ * find the appropriate pidlist for our purpose (given procs vs tasks)
+ * returns with the lock on that pidlist already held, and takes care
+ * of the use count, or returns NULL with no locks held if we're out of
+ * memory.
  */
-static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp)
+static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
+                                                  enum cgroup_filetype type)
 {
-        int n = 0, pid;
+        struct cgroup_pidlist *l;
+        /* don't need task_nsproxy() if we're looking at ourself */
+        struct pid_namespace *ns = get_pid_ns(current->nsproxy->pid_ns);
+        /*
+         * We can't drop the pidlist_mutex before taking the l->mutex in case
+         * the last ref-holder is trying to remove l from the list at the same
+         * time. Holding the pidlist_mutex precludes somebody taking whichever
+         * list we find out from under us - compare release_pid_array().
+         */
+        mutex_lock(&cgrp->pidlist_mutex);
+        list_for_each_entry(l, &cgrp->pidlists, links) {
+                if (l->key.type == type && l->key.ns == ns) {
+                        /* found a matching list - drop the extra refcount */
+                        put_pid_ns(ns);
+                        /* make sure l doesn't vanish out from under us */
+                        down_write(&l->mutex);
+                        mutex_unlock(&cgrp->pidlist_mutex);
+                        l->use_count++;
+                        return l;
+                }
+        }
+        /* entry not found; create a new one */
+        l = kmalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
+        if (!l) {
+                mutex_unlock(&cgrp->pidlist_mutex);
+                put_pid_ns(ns);
+                return l;
+        }
+        init_rwsem(&l->mutex);
+        down_write(&l->mutex);
+        l->key.type = type;
+        l->key.ns = ns;
+        l->use_count = 0; /* don't increment here */
+        l->list = NULL;
+        l->owner = cgrp;
+        list_add(&l->links, &cgrp->pidlists);
+        mutex_unlock(&cgrp->pidlist_mutex);
+        return l;
+}
+
+/*
+ * Load a cgroup's pidarray with either procs' tgids or tasks' pids
+ */
+static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
+                              struct cgroup_pidlist **lp)
+{
+        pid_t *array;
+        int length;
+        int pid, n = 0; /* used for populating the array */
         struct cgroup_iter it;
         struct task_struct *tsk;
+        struct cgroup_pidlist *l;
+
+        /*
+         * If cgroup gets more users after we read count, we won't have
+         * enough space - tough.  This race is indistinguishable to the
+         * caller from the case that the additional cgroup users didn't
+         * show up until sometime later on.
+         */
+        length = cgroup_task_count(cgrp);
+        array = pidlist_allocate(length);
+        if (!array)
+                return -ENOMEM;
+        /* now, populate the array */
         cgroup_iter_start(cgrp, &it);
         while ((tsk = cgroup_iter_next(cgrp, &it))) {
-                if (unlikely(n == npids))
+                if (unlikely(n == length))
                         break;
-                pid = task_pid_vnr(tsk);
-                if (pid > 0)
-                        pidarray[n++] = pid;
+                /* get tgid or pid for procs or tasks file respectively */
+                if (type == CGROUP_FILE_PROCS)
+                        pid = task_tgid_vnr(tsk);
+                else
+                        pid = task_pid_vnr(tsk);
+                if (pid > 0) /* make sure to only use valid results */
+                        array[n++] = pid;
         }
         cgroup_iter_end(cgrp, &it);
-        return n;
+        length = n;
+        /* now sort & (if procs) strip out duplicates */
+        sort(array, length, sizeof(pid_t), cmppid, NULL);
+        if (type == CGROUP_FILE_PROCS)
+                length = pidlist_uniq(&array, length);
+        l = cgroup_pidlist_find(cgrp, type);
+        if (!l) {
+                pidlist_free(array);
+                return -ENOMEM;
+        }
+        /* store array, freeing old if necessary - lock already held */
+        pidlist_free(l->list);
+        l->list = array;
+        l->length = length;
+        l->use_count++;
+        up_write(&l->mutex);
+        *lp = l;
+        return 0;
 }
 
 /**
@@ -2216,37 +2604,14 @@ err:
         return ret;
 }
 
-/*
- * Cache pids for all threads in the same pid namespace that are
- * opening the same "tasks" file.
- */
-struct cgroup_pids {
-        /* The node in cgrp->pids_list */
-        struct list_head list;
-        /* The cgroup those pids belong to */
-        struct cgroup *cgrp;
-        /* The namepsace those pids belong to */
-        struct pid_namespace *ns;
-        /* Array of process ids in the cgroup */
-        pid_t *tasks_pids;
-        /* How many files are using the this tasks_pids array */
-        int use_count;
-        /* Length of the current tasks_pids array */
-        int length;
-};
-
-static int cmppid(const void *a, const void *b)
-{
-        return *(pid_t *)a - *(pid_t *)b;
-}
 
 /*
- * seq_file methods for the "tasks" file. The seq_file position is the
+ * seq_file methods for the tasks/procs files. The seq_file position is the
  * next pid to display; the seq_file iterator is a pointer to the pid
- * in the cgroup->tasks_pids array.
+ * in the cgroup->l->list array.
  */
 
-static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos)
+static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
 {
         /*
          * Initially we receive a position value that corresponds to
@@ -2254,48 +2619,45 @@ static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos)
          * after a seek to the start). Use a binary-search to find the
          * next pid to display, if any
          */
-        struct cgroup_pids *cp = s->private;
-        struct cgroup *cgrp = cp->cgrp;
+        struct cgroup_pidlist *l = s->private;
         int index = 0, pid = *pos;
         int *iter;
 
-        down_read(&cgrp->pids_mutex);
+        down_read(&l->mutex);
         if (pid) {
-                int end = cp->length;
+                int end = l->length;
 
                 while (index < end) {
                         int mid = (index + end) / 2;
-                        if (cp->tasks_pids[mid] == pid) {
+                        if (l->list[mid] == pid) {
                                 index = mid;
                                 break;
-                        } else if (cp->tasks_pids[mid] <= pid)
+                        } else if (l->list[mid] <= pid)
                                 index = mid + 1;
                         else
                                 end = mid;
                 }
         }
         /* If we're off the end of the array, we're done */
-        if (index >= cp->length)
+        if (index >= l->length)
                 return NULL;
         /* Update the abstract position to be the actual pid that we found */
-        iter = cp->tasks_pids + index;
+        iter = l->list + index;
         *pos = *iter;
         return iter;
 }
 
-static void cgroup_tasks_stop(struct seq_file *s, void *v)
+static void cgroup_pidlist_stop(struct seq_file *s, void *v)
 {
-        struct cgroup_pids *cp = s->private;
-        struct cgroup *cgrp = cp->cgrp;
-        up_read(&cgrp->pids_mutex);
+        struct cgroup_pidlist *l = s->private;
+        up_read(&l->mutex);
 }
 
-static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos)
+static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
 {
-        struct cgroup_pids *cp = s->private;
-        int *p = v;
-        int *end = cp->tasks_pids + cp->length;
-
+        struct cgroup_pidlist *l = s->private;
+        pid_t *p = v;
+        pid_t *end = l->list + l->length;
         /*
          * Advance to the next pid in the array. If this goes off the
          * end, we're done
@@ -2309,124 +2671,107 @@ static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos)
         }
 }
 
-static int cgroup_tasks_show(struct seq_file *s, void *v)
+static int cgroup_pidlist_show(struct seq_file *s, void *v)
 {
         return seq_printf(s, "%d\n", *(int *)v);
 }
 
-static struct seq_operations cgroup_tasks_seq_operations = {
-        .start = cgroup_tasks_start,
-        .stop = cgroup_tasks_stop,
-        .next = cgroup_tasks_next,
-        .show = cgroup_tasks_show,
+/*
+ * seq_operations functions for iterating on pidlists through seq_file -
+ * independent of whether it's tasks or procs
+ */
+static const struct seq_operations cgroup_pidlist_seq_operations = {
+        .start = cgroup_pidlist_start,
+        .stop = cgroup_pidlist_stop,
+        .next = cgroup_pidlist_next,
+        .show = cgroup_pidlist_show,
 };
 
-static void release_cgroup_pid_array(struct cgroup_pids *cp)
+static void cgroup_release_pid_array(struct cgroup_pidlist *l)
 {
-        struct cgroup *cgrp = cp->cgrp;
-
-        down_write(&cgrp->pids_mutex);
-        BUG_ON(!cp->use_count);
-        if (!--cp->use_count) {
-                list_del(&cp->list);
-                put_pid_ns(cp->ns);
-                kfree(cp->tasks_pids);
-                kfree(cp);
+        /*
+         * the case where we're the last user of this particular pidlist will
+         * have us remove it from the cgroup's list, which entails taking the
+         * mutex. since in pidlist_find the pidlist->lock depends on cgroup->
+         * pidlist_mutex, we have to take pidlist_mutex first.
+         */
+        mutex_lock(&l->owner->pidlist_mutex);
+        down_write(&l->mutex);
+        BUG_ON(!l->use_count);
+        if (!--l->use_count) {
+                /* we're the last user if refcount is 0; remove and free */
+                list_del(&l->links);
+                mutex_unlock(&l->owner->pidlist_mutex);
+                pidlist_free(l->list);
+                put_pid_ns(l->key.ns);
+                up_write(&l->mutex);
+                kfree(l);
+                return;
         }
-        up_write(&cgrp->pids_mutex);
+        mutex_unlock(&l->owner->pidlist_mutex);
+        up_write(&l->mutex);
 }
 
-static int cgroup_tasks_release(struct inode *inode, struct file *file)
+static int cgroup_pidlist_release(struct inode *inode, struct file *file)
 {
-        struct seq_file *seq;
-        struct cgroup_pids *cp;
-
+        struct cgroup_pidlist *l;
         if (!(file->f_mode & FMODE_READ))
                 return 0;
-
-        seq = file->private_data;
-        cp = seq->private;
-
-        release_cgroup_pid_array(cp);
+        /*
+         * the seq_file will only be initialized if the file was opened for
+         * reading; hence we check if it's not null only in that case.
+         */
+        l = ((struct seq_file *)file->private_data)->private;
+        cgroup_release_pid_array(l);
         return seq_release(inode, file);
 }
 
-static struct file_operations cgroup_tasks_operations = {
+static const struct file_operations cgroup_pidlist_operations = {
         .read = seq_read,
         .llseek = seq_lseek,
         .write = cgroup_file_write,
-        .release = cgroup_tasks_release,
+        .release = cgroup_pidlist_release,
 };
 
 /*
- * Handle an open on 'tasks' file.  Prepare an array containing the
- * process id's of tasks currently attached to the cgroup being opened.
+ * The following functions handle opens on a file that displays a pidlist
+ * (tasks or procs). Prepare an array of the process/thread IDs of whoever's
+ * in the cgroup.
  */
-
-static int cgroup_tasks_open(struct inode *unused, struct file *file)
+/* helper function for the two below it */
+static int cgroup_pidlist_open(struct file *file, enum cgroup_filetype type)
 {
         struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
-        struct pid_namespace *ns = current->nsproxy->pid_ns;
-        struct cgroup_pids *cp;
-        pid_t *pidarray;
-        int npids;
+        struct cgroup_pidlist *l;
         int retval;
 
         /* Nothing to do for write-only files */
         if (!(file->f_mode & FMODE_READ))
                 return 0;
 
-        /*
-         * If cgroup gets more users after we read count, we won't have
-         * enough space - tough.  This race is indistinguishable to the
-         * caller from the case that the additional cgroup users didn't
-         * show up until sometime later on.
-         */
-        npids = cgroup_task_count(cgrp);
-        pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL);
-        if (!pidarray)
-                return -ENOMEM;
-        npids = pid_array_load(pidarray, npids, cgrp);
-        sort(pidarray, npids, sizeof(pid_t), cmppid, NULL);
-
-        /*
-         * Store the array in the cgroup, freeing the old
-         * array if necessary
-         */
-        down_write(&cgrp->pids_mutex);
-
-        list_for_each_entry(cp, &cgrp->pids_list, list) {
-                if (ns == cp->ns)
-                        goto found;
-        }
-
-        cp = kzalloc(sizeof(*cp), GFP_KERNEL);
-        if (!cp) {
-                up_write(&cgrp->pids_mutex);
-                kfree(pidarray);
-                return -ENOMEM;
-        }
-        cp->cgrp = cgrp;
-        cp->ns = ns;
-        get_pid_ns(ns);
-        list_add(&cp->list, &cgrp->pids_list);
-found:
-        kfree(cp->tasks_pids);
-        cp->tasks_pids = pidarray;
-        cp->length = npids;
-        cp->use_count++;
-        up_write(&cgrp->pids_mutex);
-
-        file->f_op = &cgroup_tasks_operations;
+        /* have the array populated */
+        retval = pidlist_array_load(cgrp, type, &l);
+        if (retval)
+                return retval;
+        /* configure file information */
+        file->f_op = &cgroup_pidlist_operations;
 
-        retval = seq_open(file, &cgroup_tasks_seq_operations);
+        retval = seq_open(file, &cgroup_pidlist_seq_operations);
         if (retval) {
-                release_cgroup_pid_array(cp);
+                cgroup_release_pid_array(l);
                 return retval;
         }
-        ((struct seq_file *)file->private_data)->private = cp;
+        ((struct seq_file *)file->private_data)->private = l;
         return 0;
 }
+static int cgroup_tasks_open(struct inode *unused, struct file *file)
+{
+        return cgroup_pidlist_open(file, CGROUP_FILE_TASKS);
+}
+static int cgroup_procs_open(struct inode *unused, struct file *file)
+{
+        return cgroup_pidlist_open(file, CGROUP_FILE_PROCS);
+}
 
 static u64 cgroup_read_notify_on_release(struct cgroup *cgrp,
                                             struct cftype *cft)
@@ -2449,21 +2794,27 @@ static int cgroup_write_notify_on_release(struct cgroup *cgrp,
 /*
  * for the common functions, 'private' gives the type of file
  */
+/* for hysterical raisins, we can't put this on the older files */
+#define CGROUP_FILE_GENERIC_PREFIX "cgroup."
 static struct cftype files[] = {
         {
                 .name = "tasks",
                 .open = cgroup_tasks_open,
                 .write_u64 = cgroup_tasks_write,
-                .release = cgroup_tasks_release,
-                .private = FILE_TASKLIST,
+                .release = cgroup_pidlist_release,
                 .mode = S_IRUGO | S_IWUSR,
         },
-
+        {
+                .name = CGROUP_FILE_GENERIC_PREFIX "procs",
+                .open = cgroup_procs_open,
+                /* .write_u64 = cgroup_procs_write, TODO */
+                .release = cgroup_pidlist_release,
+                .mode = S_IRUGO,
+        },
         {
                 .name = "notify_on_release",
                 .read_u64 = cgroup_read_notify_on_release,
                 .write_u64 = cgroup_write_notify_on_release,
-                .private = FILE_NOTIFY_ON_RELEASE,
         },
 };
 
@@ -2472,7 +2823,6 @@ static struct cftype cft_release_agent = {
         .read_seq_string = cgroup_release_agent_show,
         .write_string = cgroup_release_agent_write,
         .max_write_len = PATH_MAX,
-        .private = FILE_RELEASE_AGENT,
 };
 
 static int cgroup_populate_dir(struct cgroup *cgrp)
@@ -2879,6 +3229,7 @@ int __init cgroup_init_early(void)
         init_task.cgroups = &init_css_set;
 
         init_css_set_link.cg = &init_css_set;
+        init_css_set_link.cgrp = dummytop;
         list_add(&init_css_set_link.cgrp_link_list,
                  &rootnode.top_cgroup.css_sets);
         list_add(&init_css_set_link.cg_link_list,
@@ -2933,7 +3284,7 @@ int __init cgroup_init(void)
         /* Add init_css_set to the hash table */
         hhead = css_set_hash(init_css_set.subsys);
         hlist_add_head(&init_css_set.hlist, hhead);
-
+        BUG_ON(!init_root_id(&rootnode));
         err = register_filesystem(&cgroup_fs_type);
         if (err < 0)
                 goto out;
@@ -2986,15 +3337,16 @@ static int proc_cgroup_show(struct seq_file *m, void *v)
         for_each_active_root(root) {
                 struct cgroup_subsys *ss;
                 struct cgroup *cgrp;
-                int subsys_id;
                 int count = 0;
 
-                seq_printf(m, "%lu:", root->subsys_bits);
+                seq_printf(m, "%d:", root->hierarchy_id);
                 for_each_subsys(root, ss)
                         seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
+                if (strlen(root->name))
+                        seq_printf(m, "%sname=%s", count ? "," : "",
+                                   root->name);
                 seq_putc(m, ':');
-                get_first_subsys(&root->top_cgroup, NULL, &subsys_id);
-                cgrp = task_cgroup(tsk, subsys_id);
+                cgrp = task_cgroup_from_root(tsk, root);
                 retval = cgroup_path(cgrp, buf, PAGE_SIZE);
                 if (retval < 0)
                         goto out_unlock;
@@ -3017,7 +3369,7 @@ static int cgroup_open(struct inode *inode, struct file *file)
         return single_open(file, proc_cgroup_show, pid);
 }
 
-struct file_operations proc_cgroup_operations = {
+const struct file_operations proc_cgroup_operations = {
         .open           = cgroup_open,
         .read           = seq_read,
         .llseek         = seq_lseek,
@@ -3033,8 +3385,8 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
         mutex_lock(&cgroup_mutex);
         for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
                 struct cgroup_subsys *ss = subsys[i];
-                seq_printf(m, "%s\t%lu\t%d\t%d\n",
-                           ss->name, ss->root->subsys_bits,
+                seq_printf(m, "%s\t%d\t%d\t%d\n",
+                           ss->name, ss->root->hierarchy_id,
                            ss->root->number_of_cgroups, !ss->disabled);
         }
         mutex_unlock(&cgroup_mutex);
@@ -3046,7 +3398,7 @@ static int cgroupstats_open(struct inode *inode, struct file *file)
         return single_open(file, proc_cgroupstats_show, NULL);
 }
 
-static struct file_operations proc_cgroupstats_operations = {
+static const struct file_operations proc_cgroupstats_operations = {
         .open = cgroupstats_open,
         .read = seq_read,
         .llseek = seq_lseek,
@@ -3320,13 +3672,11 @@ int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task)
 {
         int ret;
         struct cgroup *target;
-        int subsys_id;
 
         if (cgrp == dummytop)
                 return 1;
 
-        get_first_subsys(cgrp, NULL, &subsys_id);
-        target = task_cgroup(task, subsys_id);
+        target = task_cgroup_from_root(task, cgrp->root);
         while (cgrp != target && cgrp!= cgrp->top_cgroup)
                 cgrp = cgrp->parent;
         ret = (cgrp == target);
@@ -3358,8 +3708,10 @@ static void check_for_release(struct cgroup *cgrp)
 void __css_put(struct cgroup_subsys_state *css)
 {
         struct cgroup *cgrp = css->cgroup;
+        int val;
         rcu_read_lock();
-        if (atomic_dec_return(&css->refcnt) == 1) {
+        val = atomic_dec_return(&css->refcnt);
+        if (val == 1) {
                 if (notify_on_release(cgrp)) {
                         set_bit(CGRP_RELEASABLE, &cgrp->flags);
                         check_for_release(cgrp);
@@ -3367,6 +3719,7 @@ void __css_put(struct cgroup_subsys_state *css)
                 cgroup_wakeup_rmdir_waiter(cgrp);
         }
         rcu_read_unlock();
+        WARN_ON_ONCE(val < 1);
 }
 
 /*
@@ -3693,3 +4046,154 @@ css_get_next(struct cgroup_subsys *ss, int id,
         return ret;
 }
 
+#ifdef CONFIG_CGROUP_DEBUG
+static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss,
+                                                   struct cgroup *cont)
+{
+        struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
+
+        if (!css)
+                return ERR_PTR(-ENOMEM);
+
+        return css;
+}
+
+static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+        kfree(cont->subsys[debug_subsys_id]);
+}
+
+static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft)
+{
+        return atomic_read(&cont->count);
+}
+
+static u64 debug_taskcount_read(struct cgroup *cont, struct cftype *cft)
+{
+        return cgroup_task_count(cont);
+}
+
+static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
+{
+        return (u64)(unsigned long)current->cgroups;
+}
+
+static u64 current_css_set_refcount_read(struct cgroup *cont,
+                                           struct cftype *cft)
+{
+        u64 count;
+
+        rcu_read_lock();
+        count = atomic_read(&current->cgroups->refcount);
+        rcu_read_unlock();
+        return count;
+}
+
+static int current_css_set_cg_links_read(struct cgroup *cont,
+                                         struct cftype *cft,
+                                         struct seq_file *seq)
+{
+        struct cg_cgroup_link *link;
+        struct css_set *cg;
+
+        read_lock(&css_set_lock);
+        rcu_read_lock();
+        cg = rcu_dereference(current->cgroups);
+        list_for_each_entry(link, &cg->cg_links, cg_link_list) {
+                struct cgroup *c = link->cgrp;
+                const char *name;
+
+                if (c->dentry)
+                        name = c->dentry->d_name.name;
+                else
+                        name = "?";
+                seq_printf(seq, "Root %d group %s\n",
+                           c->root->hierarchy_id, name);
+        }
+        rcu_read_unlock();
+        read_unlock(&css_set_lock);
+        return 0;
+}
+
+#define MAX_TASKS_SHOWN_PER_CSS 25
+static int cgroup_css_links_read(struct cgroup *cont,
+                                 struct cftype *cft,
+                                 struct seq_file *seq)
+{
+        struct cg_cgroup_link *link;
+
+        read_lock(&css_set_lock);
+        list_for_each_entry(link, &cont->css_sets, cgrp_link_list) {
+                struct css_set *cg = link->cg;
+                struct task_struct *task;
+                int count = 0;
+                seq_printf(seq, "css_set %p\n", cg);
+                list_for_each_entry(task, &cg->tasks, cg_list) {
+                        if (count++ > MAX_TASKS_SHOWN_PER_CSS) {
+                                seq_puts(seq, "  ...\n");
+                                break;
+                        } else {
+                                seq_printf(seq, "  task %d\n",
+                                           task_pid_vnr(task));
+                        }
+                }
+        }
+        read_unlock(&css_set_lock);
+        return 0;
+}
+
+static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
+{
+        return test_bit(CGRP_RELEASABLE, &cgrp->flags);
+}
+
+static struct cftype debug_files[] =  {
+        {
+                .name = "cgroup_refcount",
+                .read_u64 = cgroup_refcount_read,
+        },
+        {
+                .name = "taskcount",
+                .read_u64 = debug_taskcount_read,
+        },
+
+        {
+                .name = "current_css_set",
+                .read_u64 = current_css_set_read,
+        },
+
+        {
+                .name = "current_css_set_refcount",
+                .read_u64 = current_css_set_refcount_read,
+        },
+
+        {
+                .name = "current_css_set_cg_links",
+                .read_seq_string = current_css_set_cg_links_read,
+        },
+
+        {
+                .name = "cgroup_css_links",
+                .read_seq_string = cgroup_css_links_read,
+        },
+
+        {
+                .name = "releasable",
+                .read_u64 = releasable_read,
+        },
+};
+
+static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+        return cgroup_add_files(cont, ss, debug_files,
+                                ARRAY_SIZE(debug_files));
+}
+
+struct cgroup_subsys debug_subsys = {
+        .name = "debug",
+        .create = debug_create,
+        .destroy = debug_destroy,
+        .populate = debug_populate,
+        .subsys_id = debug_subsys_id,
+};
+#endif /* CONFIG_CGROUP_DEBUG */
diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c
deleted file mode 100644
index 0c92d797baa6..000000000000
--- a/kernel/cgroup_debug.c
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * kernel/cgroup_debug.c - Example cgroup subsystem that
- * exposes debug info
- *
- * Copyright (C) Google Inc, 2007
- *
- * Developed by Paul Menage (menage@google.com)
- *
- */
-
-#include <linux/cgroup.h>
-#include <linux/fs.h>
-#include <linux/slab.h>
-#include <linux/rcupdate.h>
-
-#include <asm/atomic.h>
-
-static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss,
-                                                   struct cgroup *cont)
-{
-        struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
-
-        if (!css)
-                return ERR_PTR(-ENOMEM);
-
-        return css;
-}
-
-static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
-{
-        kfree(cont->subsys[debug_subsys_id]);
-}
-
-static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft)
-{
-        return atomic_read(&cont->count);
-}
-
-static u64 taskcount_read(struct cgroup *cont, struct cftype *cft)
-{
-        u64 count;
-
-        count = cgroup_task_count(cont);
-        return count;
-}
-
-static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
-{
-        return (u64)(long)current->cgroups;
-}
-
-static u64 current_css_set_refcount_read(struct cgroup *cont,
-                                           struct cftype *cft)
-{
-        u64 count;
-
-        rcu_read_lock();
-        count = atomic_read(&current->cgroups->refcount);
-        rcu_read_unlock();
-        return count;
-}
-
-static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
-{
-        return test_bit(CGRP_RELEASABLE, &cgrp->flags);
-}
-
-static struct cftype files[] =  {
-        {
-                .name = "cgroup_refcount",
-                .read_u64 = cgroup_refcount_read,
-        },
-        {
-                .name = "taskcount",
-                .read_u64 = taskcount_read,
-        },
-
-        {
-                .name = "current_css_set",
-                .read_u64 = current_css_set_read,
-        },
-
-        {
-                .name = "current_css_set_refcount",
-                .read_u64 = current_css_set_refcount_read,
-        },
-
-        {
-                .name = "releasable",
-                .read_u64 = releasable_read,
-        },
-};
-
-static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
-{
-        return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
-}
-
-struct cgroup_subsys debug_subsys = {
-        .name = "debug",
-        .create = debug_create,
-        .destroy = debug_destroy,
-        .populate = debug_populate,
-        .subsys_id = debug_subsys_id,
-};
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index fb249e2bcada..59e9ef6aab40 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -159,7 +159,7 @@ static bool is_task_frozen_enough(struct task_struct *task)
  */
 static int freezer_can_attach(struct cgroup_subsys *ss,
                               struct cgroup *new_cgroup,
-                              struct task_struct *task)
+                              struct task_struct *task, bool threadgroup)
 {
         struct freezer *freezer;
 
@@ -177,6 +177,19 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
         if (freezer->state == CGROUP_FROZEN)
                 return -EBUSY;
 
+        if (threadgroup) {
+                struct task_struct *c;
+
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
+                        if (is_task_frozen_enough(c)) {
+                                rcu_read_unlock();
+                                return -EBUSY;
+                        }
+                }
+                rcu_read_unlock();
+        }
+
         return 0;
 }
 
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index b81f7f096e1c..d247381e7371 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1324,9 +1324,10 @@ static int fmeter_getrate(struct fmeter *fmp)
 static cpumask_var_t cpus_attach;
 
 /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys *ss,
-                             struct cgroup *cont, struct task_struct *tsk)
+static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+                             struct task_struct *tsk, bool threadgroup)
 {
+        int ret;
         struct cpuset *cs = cgroup_cs(cont);
 
         if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
@@ -1343,18 +1344,51 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
         if (tsk->flags & PF_THREAD_BOUND)
                 return -EINVAL;
 
-        return security_task_setscheduler(tsk, 0, NULL);
+        ret = security_task_setscheduler(tsk, 0, NULL);
+        if (ret)
+                return ret;
+        if (threadgroup) {
+                struct task_struct *c;
+
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+                        ret = security_task_setscheduler(c, 0, NULL);
+                        if (ret) {
+                                rcu_read_unlock();
+                                return ret;
+                        }
+                }
+                rcu_read_unlock();
+        }
+        return 0;
+}
+
+static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to,
+                               struct cpuset *cs)
+{
+        int err;
+        /*
+         * can_attach beforehand should guarantee that this doesn't fail.
+         * TODO: have a better way to handle failure here
+         */
+        err = set_cpus_allowed_ptr(tsk, cpus_attach);
+        WARN_ON_ONCE(err);
+
+        task_lock(tsk);
+        cpuset_change_task_nodemask(tsk, to);
+        task_unlock(tsk);
+        cpuset_update_task_spread_flag(cs, tsk);
+
 }
 
-static void cpuset_attach(struct cgroup_subsys *ss,
-                          struct cgroup *cont, struct cgroup *oldcont,
-                          struct task_struct *tsk)
+static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+                          struct cgroup *oldcont, struct task_struct *tsk,
+                          bool threadgroup)
 {
         nodemask_t from, to;
         struct mm_struct *mm;
         struct cpuset *cs = cgroup_cs(cont);
         struct cpuset *oldcs = cgroup_cs(oldcont);
-        int err;
 
         if (cs == &top_cpuset) {
                 cpumask_copy(cpus_attach, cpu_possible_mask);
@@ -1363,15 +1397,19 @@ static void cpuset_attach(struct cgroup_subsys *ss,
                 guarantee_online_cpus(cs, cpus_attach);
                 guarantee_online_mems(cs, &to);
         }
-        err = set_cpus_allowed_ptr(tsk, cpus_attach);
-        if (err)
-                return;
 
-        task_lock(tsk);
-        cpuset_change_task_nodemask(tsk, &to);
-        task_unlock(tsk);
-        cpuset_update_task_spread_flag(cs, tsk);
+        /* do per-task migration stuff possibly for each in the threadgroup */
+        cpuset_attach_task(tsk, &to, cs);
+        if (threadgroup) {
+                struct task_struct *c;
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+                        cpuset_attach_task(c, &to, cs);
+                }
+                rcu_read_unlock();
+        }
 
+        /* change mm; only needs to be done once even if threadgroup */
         from = oldcs->mems_allowed;
         to = cs->mems_allowed;
         mm = get_task_mm(tsk);
diff --git a/kernel/cred.c b/kernel/cred.c
index d7f7a01082eb..dd76cfe5f5b0 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -782,6 +782,25 @@ EXPORT_SYMBOL(set_create_files_as);
 
 #ifdef CONFIG_DEBUG_CREDENTIALS
 
+bool creds_are_invalid(const struct cred *cred)
+{
+        if (cred->magic != CRED_MAGIC)
+                return true;
+        if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))
+                return true;
+#ifdef CONFIG_SECURITY_SELINUX
+        if (selinux_is_enabled()) {
+                if ((unsigned long) cred->security < PAGE_SIZE)
+                        return true;
+                if ((*(u32 *)cred->security & 0xffffff00) ==
+                    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
+                        return true;
+        }
+#endif
+        return false;
+}
+EXPORT_SYMBOL(creds_are_invalid);
+
 /*
  * dump invalid credentials
  */
diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index abb6e17505e2..ead9b610aa71 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -15,6 +15,7 @@
 
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/taskstats.h>
 #include <linux/time.h>
 #include <linux/sysctl.h>
 #include <linux/delayacct.h>
diff --git a/kernel/exit.c b/kernel/exit.c
index ae5d8660ddff..e61891f80123 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -47,7 +47,7 @@
 #include <linux/tracehook.h>
 #include <linux/fs_struct.h>
 #include <linux/init_task.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <trace/events/sched.h>
 
 #include <asm/uaccess.h>
@@ -154,8 +154,8 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
 {
         struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
 
-#ifdef CONFIG_PERF_COUNTERS
-        WARN_ON_ONCE(tsk->perf_counter_ctxp);
+#ifdef CONFIG_PERF_EVENTS
+        WARN_ON_ONCE(tsk->perf_event_ctxp);
 #endif
         trace_sched_process_free(tsk);
         put_task_struct(tsk);
@@ -359,8 +359,10 @@ void __set_special_pids(struct pid *pid)
 {
         struct task_struct *curr = current->group_leader;
 
-        if (task_session(curr) != pid)
+        if (task_session(curr) != pid) {
                 change_pid(curr, PIDTYPE_SID, pid);
+                proc_sid_connector(curr);
+        }
 
         if (task_pgrp(curr) != pid)
                 change_pid(curr, PIDTYPE_PGID, pid);
@@ -945,6 +947,8 @@ NORET_TYPE void do_exit(long code)
         if (group_dead) {
                 hrtimer_cancel(&tsk->signal->real_timer);
                 exit_itimers(tsk->signal);
+                if (tsk->mm)
+                        setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
         }
         acct_collect(code, group_dead);
         if (group_dead)
@@ -972,8 +976,6 @@ NORET_TYPE void do_exit(long code)
                 disassociate_ctty(1);
 
         module_put(task_thread_info(tsk)->exec_domain->module);
-        if (tsk->binfmt)
-                module_put(tsk->binfmt->module);
 
         proc_exit_connector(tsk);
 
@@ -981,7 +983,7 @@ NORET_TYPE void do_exit(long code)
          * Flush inherited counters to the parent - before the parent
          * gets woken up by child-exit notifications.
          */
-        perf_counter_exit_task(tsk);
+        perf_event_exit_task(tsk);
 
         exit_notify(tsk, group_dead);
 #ifdef CONFIG_NUMA
@@ -989,8 +991,6 @@ NORET_TYPE void do_exit(long code)
         tsk->mempolicy = NULL;
 #endif
 #ifdef CONFIG_FUTEX
-        if (unlikely(!list_empty(&tsk->pi_state_list)))
-                exit_pi_state_list(tsk);
         if (unlikely(current->pi_state_cache))
                 kfree(current->pi_state_cache);
 #endif
@@ -1093,28 +1093,28 @@ struct wait_opts {
         int __user              *wo_stat;
         struct rusage __user    *wo_rusage;
 
+        wait_queue_t            child_wait;
         int                     notask_error;
 };
 
-static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
+static inline
+struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
 {
-        struct pid *pid = NULL;
-        if (type == PIDTYPE_PID)
-                pid = task->pids[type].pid;
-        else if (type < PIDTYPE_MAX)
-                pid = task->group_leader->pids[type].pid;
-        return pid;
+        if (type != PIDTYPE_PID)
+                task = task->group_leader;
+        return task->pids[type].pid;
 }
 
-static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
 {
-        int err;
-
-        if (wo->wo_type < PIDTYPE_MAX) {
-                if (task_pid_type(p, wo->wo_type) != wo->wo_pid)
-                        return 0;
-        }
+        return  wo->wo_type == PIDTYPE_MAX ||
+                task_pid_type(p, wo->wo_type) == wo->wo_pid;
+}
 
+static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+{
+        if (!eligible_pid(wo, p))
+                return 0;
         /* Wait for all children (clone and not) if __WALL is set;
          * otherwise, wait for clone children *only* if __WCLONE is
          * set; otherwise, wait for non-clone children *only*.  (Note:
@@ -1124,10 +1124,6 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p)
             && !(wo->wo_flags & __WALL))
                 return 0;
 
-        err = security_task_wait(p);
-        if (err)
-                return err;
-
         return 1;
 }
 
@@ -1140,18 +1136,20 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
 
         put_task_struct(p);
         infop = wo->wo_info;
-        if (!retval)
-                retval = put_user(SIGCHLD, &infop->si_signo);
-        if (!retval)
-                retval = put_user(0, &infop->si_errno);
-        if (!retval)
-                retval = put_user((short)why, &infop->si_code);
-        if (!retval)
-                retval = put_user(pid, &infop->si_pid);
-        if (!retval)
-                retval = put_user(uid, &infop->si_uid);
-        if (!retval)
-                retval = put_user(status, &infop->si_status);
+        if (infop) {
+                if (!retval)
+                        retval = put_user(SIGCHLD, &infop->si_signo);
+                if (!retval)
+                        retval = put_user(0, &infop->si_errno);
+                if (!retval)
+                        retval = put_user((short)why, &infop->si_code);
+                if (!retval)
+                        retval = put_user(pid, &infop->si_pid);
+                if (!retval)
+                        retval = put_user(uid, &infop->si_uid);
+                if (!retval)
+                        retval = put_user(status, &infop->si_status);
+        }
         if (!retval)
                 retval = pid;
         return retval;
@@ -1208,6 +1206,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
         if (likely(!traced) && likely(!task_detached(p))) {
                 struct signal_struct *psig;
                 struct signal_struct *sig;
+                unsigned long maxrss;
 
                 /*
                  * The resource counters for the group leader are in its
@@ -1256,6 +1255,9 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
                 psig->coublock +=
                         task_io_get_oublock(p) +
                         sig->oublock + sig->coublock;
+                maxrss = max(sig->maxrss, sig->cmaxrss);
+                if (psig->cmaxrss < maxrss)
+                        psig->cmaxrss = maxrss;
                 task_io_accounting_add(&psig->ioac, &p->ioac);
                 task_io_accounting_add(&psig->ioac, &sig->ioac);
                 spin_unlock_irq(&p->real_parent->sighand->siglock);
@@ -1477,13 +1479,14 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
  * then ->notask_error is 0 if @p is an eligible child,
  * or another error from security_task_wait(), or still -ECHILD.
  */
-static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent,
-                                int ptrace, struct task_struct *p)
+static int wait_consider_task(struct wait_opts *wo, int ptrace,
+                                struct task_struct *p)
 {
         int ret = eligible_child(wo, p);
         if (!ret)
                 return ret;
 
+        ret = security_task_wait(p);
         if (unlikely(ret < 0)) {
                 /*
                  * If we have not yet seen any eligible child,
@@ -1545,7 +1548,7 @@ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
                  * Do not consider detached threads.
                  */
                 if (!task_detached(p)) {
-                        int ret = wait_consider_task(wo, tsk, 0, p);
+                        int ret = wait_consider_task(wo, 0, p);
                         if (ret)
                                 return ret;
                 }
@@ -1559,7 +1562,7 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
         struct task_struct *p;
 
         list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
-                int ret = wait_consider_task(wo, tsk, 1, p);
+                int ret = wait_consider_task(wo, 1, p);
                 if (ret)
                         return ret;
         }
@@ -1567,15 +1570,38 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
         return 0;
 }
 
+static int child_wait_callback(wait_queue_t *wait, unsigned mode,
+                                int sync, void *key)
+{
+        struct wait_opts *wo = container_of(wait, struct wait_opts,
+                                                child_wait);
+        struct task_struct *p = key;
+
+        if (!eligible_pid(wo, p))
+                return 0;
+
+        if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent)
+                return 0;
+
+        return default_wake_function(wait, mode, sync, key);
+}
+
+void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
+{
+        __wake_up_sync_key(&parent->signal->wait_chldexit,
+                                TASK_INTERRUPTIBLE, 1, p);
+}
+
 static long do_wait(struct wait_opts *wo)
 {
-        DECLARE_WAITQUEUE(wait, current);
         struct task_struct *tsk;
         int retval;
 
         trace_sched_process_wait(wo->wo_pid);
 
-        add_wait_queue(&current->signal->wait_chldexit,&wait);
+        init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
+        wo->child_wait.private = current;
+        add_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
 repeat:
         /*
          * If there is nothing that can match our critiera just get out.
@@ -1616,32 +1642,7 @@ notask:
         }
 end:
         __set_current_state(TASK_RUNNING);
-        remove_wait_queue(&current->signal->wait_chldexit,&wait);
-        if (wo->wo_info) {
-                struct siginfo __user *infop = wo->wo_info;
-
-                if (retval > 0)
-                        retval = 0;
-                else {
-                        /*
-                         * For a WNOHANG return, clear out all the fields
-                         * we would set so the user can easily tell the
-                         * difference.
-                         */
-                        if (!retval)
-                                retval = put_user(0, &infop->si_signo);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_errno);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_code);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_pid);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_uid);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_status);
-                }
-        }
+        remove_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
         return retval;
 }
 
@@ -1686,6 +1687,29 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
         wo.wo_stat      = NULL;
         wo.wo_rusage    = ru;
         ret = do_wait(&wo);
+
+        if (ret > 0) {
+                ret = 0;
+        } else if (infop) {
+                /*
+                 * For a WNOHANG return, clear out all the fields
+                 * we would set so the user can easily tell the
+                 * difference.
+                 */
+                if (!ret)
+                        ret = put_user(0, &infop->si_signo);
+                if (!ret)
+                        ret = put_user(0, &infop->si_errno);
+                if (!ret)
+                        ret = put_user(0, &infop->si_code);
+                if (!ret)
+                        ret = put_user(0, &infop->si_pid);
+                if (!ret)
+                        ret = put_user(0, &infop->si_uid);
+                if (!ret)
+                        ret = put_user(0, &infop->si_status);
+        }
+
         put_pid(pid);
 
         /* avoid REGPARM breakage on x86: */
diff --git a/kernel/fork.c b/kernel/fork.c
index bfee931ee3fb..4c20fff8c13a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -49,6 +49,7 @@
 #include <linux/ftrace.h>
 #include <linux/profile.h>
 #include <linux/rmap.h>
+#include <linux/ksm.h>
 #include <linux/acct.h>
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
@@ -61,7 +62,8 @@
 #include <linux/blkdev.h>
 #include <linux/fs_struct.h>
 #include <linux/magic.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
+#include <linux/posix-timers.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -136,9 +138,17 @@ struct kmem_cache *vm_area_cachep;
 /* SLAB cache for mm_struct structures (tsk->mm) */
 static struct kmem_cache *mm_cachep;
 
+static void account_kernel_stack(struct thread_info *ti, int account)
+{
+        struct zone *zone = page_zone(virt_to_page(ti));
+
+        mod_zone_page_state(zone, NR_KERNEL_STACK, account);
+}
+
 void free_task(struct task_struct *tsk)
 {
         prop_local_destroy_single(&tsk->dirties);
+        account_kernel_stack(tsk->stack, -1);
         free_thread_info(tsk->stack);
         rt_mutex_debug_task_free(tsk);
         ftrace_graph_exit_task(tsk);
@@ -253,6 +263,9 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
         tsk->btrace_seq = 0;
 #endif
         tsk->splice_pipe = NULL;
+
+        account_kernel_stack(ti, 1);
+
         return tsk;
 
 out:
@@ -288,6 +301,9 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
         rb_link = &mm->mm_rb.rb_node;
         rb_parent = NULL;
         pprev = &mm->mmap;
+        retval = ksm_fork(mm, oldmm);
+        if (retval)
+                goto out;
 
         for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
                 struct file *file;
@@ -418,22 +434,30 @@ __setup("coredump_filter=", coredump_filter_setup);
 
 #include <linux/init_task.h>
 
+static void mm_init_aio(struct mm_struct *mm)
+{
+#ifdef CONFIG_AIO
+        spin_lock_init(&mm->ioctx_lock);
+        INIT_HLIST_HEAD(&mm->ioctx_list);
+#endif
+}
+
 static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
         atomic_set(&mm->mm_users, 1);
         atomic_set(&mm->mm_count, 1);
         init_rwsem(&mm->mmap_sem);
         INIT_LIST_HEAD(&mm->mmlist);
-        mm->flags = (current->mm) ? current->mm->flags : default_dump_filter;
+        mm->flags = (current->mm) ?
+                (current->mm->flags & MMF_INIT_MASK) : default_dump_filter;
         mm->core_state = NULL;
         mm->nr_ptes = 0;
         set_mm_counter(mm, file_rss, 0);
         set_mm_counter(mm, anon_rss, 0);
         spin_lock_init(&mm->page_table_lock);
-        spin_lock_init(&mm->ioctx_lock);
-        INIT_HLIST_HEAD(&mm->ioctx_list);
         mm->free_area_cache = TASK_UNMAPPED_BASE;
         mm->cached_hole_size = ~0UL;
+        mm_init_aio(mm);
         mm_init_owner(mm, p);
 
         if (likely(!mm_alloc_pgd(mm))) {
@@ -485,6 +509,7 @@ void mmput(struct mm_struct *mm)
 
         if (atomic_dec_and_test(&mm->mm_users)) {
                 exit_aio(mm);
+                ksm_exit(mm);
                 exit_mmap(mm);
                 set_mm_exe_file(mm, NULL);
                 if (!list_empty(&mm->mmlist)) {
@@ -493,6 +518,8 @@ void mmput(struct mm_struct *mm)
                         spin_unlock(&mmlist_lock);
                 }
                 put_swap_token(mm);
+                if (mm->binfmt)
+                        module_put(mm->binfmt->module);
                 mmdrop(mm);
         }
 }
@@ -543,12 +570,18 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 
         /* Get rid of any futexes when releasing the mm */
 #ifdef CONFIG_FUTEX
-        if (unlikely(tsk->robust_list))
+        if (unlikely(tsk->robust_list)) {
                 exit_robust_list(tsk);
+                tsk->robust_list = NULL;
+        }
 #ifdef CONFIG_COMPAT
-        if (unlikely(tsk->compat_robust_list))
+        if (unlikely(tsk->compat_robust_list)) {
                 compat_exit_robust_list(tsk);
+                tsk->compat_robust_list = NULL;
+        }
 #endif
+        if (unlikely(!list_empty(&tsk->pi_state_list)))
+                exit_pi_state_list(tsk);
 #endif
 
         /* Get rid of any cached register state */
@@ -618,9 +651,14 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
         mm->hiwater_rss = get_mm_rss(mm);
         mm->hiwater_vm = mm->total_vm;
 
+        if (mm->binfmt && !try_module_get(mm->binfmt->module))
+                goto free_pt;
+
         return mm;
 
 free_pt:
+        /* don't put binfmt in mmput, we haven't got module yet */
+        mm->binfmt = NULL;
         mmput(mm);
 
 fail_nomem:
@@ -788,10 +826,10 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
         thread_group_cputime_init(sig);
 
         /* Expiration times and increments. */
-        sig->it_virt_expires = cputime_zero;
-        sig->it_virt_incr = cputime_zero;
-        sig->it_prof_expires = cputime_zero;
-        sig->it_prof_incr = cputime_zero;
+        sig->it[CPUCLOCK_PROF].expires = cputime_zero;
+        sig->it[CPUCLOCK_PROF].incr = cputime_zero;
+        sig->it[CPUCLOCK_VIRT].expires = cputime_zero;
+        sig->it[CPUCLOCK_VIRT].incr = cputime_zero;
 
         /* Cached expiration times. */
         sig->cputime_expires.prof_exp = cputime_zero;
@@ -849,6 +887,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
         sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
         sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
         sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
+        sig->maxrss = sig->cmaxrss = 0;
         task_io_accounting_init(&sig->ioac);
         sig->sum_sched_runtime = 0;
         taskstats_tgid_init(sig);
@@ -863,6 +902,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 
         tty_audit_fork(sig);
 
+        sig->oom_adj = current->signal->oom_adj;
+
         return 0;
 }
 
@@ -958,6 +999,16 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
                 return ERR_PTR(-EINVAL);
 
+        /*
+         * Siblings of global init remain as zombies on exit since they are
+         * not reaped by their parent (swapper). To solve this and to avoid
+         * multi-rooted process trees, prevent global and container-inits
+         * from creating siblings.
+         */
+        if ((clone_flags & CLONE_PARENT) &&
+                                current->signal->flags & SIGNAL_UNKILLABLE)
+                return ERR_PTR(-EINVAL);
+
         retval = security_task_create(clone_flags);
         if (retval)
                 goto fork_out;
@@ -999,9 +1050,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         if (!try_module_get(task_thread_info(p)->exec_domain->module))
                 goto bad_fork_cleanup_count;
 
-        if (p->binfmt && !try_module_get(p->binfmt->module))
-                goto bad_fork_cleanup_put_domain;
-
         p->did_exec = 0;
         delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
         copy_flags(clone_flags, p);
@@ -1075,10 +1123,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
         p->bts = NULL;
 
+        p->stack_start = stack_start;
+
         /* Perform scheduler related setup. Assign this task to a CPU. */
         sched_fork(p, clone_flags);
 
-        retval = perf_counter_init_task(p);
+        retval = perf_event_init_task(p);
         if (retval)
                 goto bad_fork_cleanup_policy;
 
@@ -1253,7 +1303,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         write_unlock_irq(&tasklist_lock);
         proc_fork_connector(p);
         cgroup_post_fork(p);
-        perf_counter_fork(p);
+        perf_event_fork(p);
         return p;
 
 bad_fork_free_pid:
@@ -1280,16 +1330,13 @@ bad_fork_cleanup_semundo:
 bad_fork_cleanup_audit:
         audit_free(p);
 bad_fork_cleanup_policy:
-        perf_counter_free_task(p);
+        perf_event_free_task(p);
 #ifdef CONFIG_NUMA
         mpol_put(p->mempolicy);
 bad_fork_cleanup_cgroup:
 #endif
         cgroup_exit(p, cgroup_callbacks_done);
         delayacct_tsk_free(p);
-        if (p->binfmt)
-                module_put(p->binfmt->module);
-bad_fork_cleanup_put_domain:
         module_put(task_thread_info(p)->exec_domain->module);
 bad_fork_cleanup_count:
         atomic_dec(&p->cred->user->processes);
diff --git a/kernel/futex.c b/kernel/futex.c
index 248dd119a86e..4949d336d88d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -89,36 +89,36 @@ struct futex_pi_state {
         union futex_key key;
 };
 
-/*
- * We use this hashed waitqueue instead of a normal wait_queue_t, so
+/**
+ * struct futex_q - The hashed futex queue entry, one per waiting task
+ * @task:               the task waiting on the futex
+ * @lock_ptr:           the hash bucket lock
+ * @key:                the key the futex is hashed on
+ * @pi_state:           optional priority inheritance state
+ * @rt_waiter:          rt_waiter storage for use with requeue_pi
+ * @requeue_pi_key:     the requeue_pi target futex key
+ * @bitset:             bitset for the optional bitmasked wakeup
+ *
+ * We use this hashed waitqueue, instead of a normal wait_queue_t, so
  * we can wake only the relevant ones (hashed queues may be shared).
  *
  * A futex_q has a woken state, just like tasks have TASK_RUNNING.
  * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
  * The order of wakup is always to make the first condition true, then
- * wake up q->waiter, then make the second condition true.
+ * the second.
+ *
+ * PI futexes are typically woken before they are removed from the hash list via
+ * the rt_mutex code. See unqueue_me_pi().
  */
 struct futex_q {
         struct plist_node list;
-        /* Waiter reference */
-        struct task_struct *task;
 
-        /* Which hash list lock to use: */
+        struct task_struct *task;
         spinlock_t *lock_ptr;
-
-        /* Key which the futex is hashed on: */
         union futex_key key;
-
-        /* Optional priority inheritance state: */
         struct futex_pi_state *pi_state;
-
-        /* rt_waiter storage for requeue_pi: */
         struct rt_mutex_waiter *rt_waiter;
-
-        /* The expected requeue pi target futex key: */
         union futex_key *requeue_pi_key;
-
-        /* Bitset for the optional bitmasked wakeup */
         u32 bitset;
 };
 
@@ -198,11 +198,12 @@ static void drop_futex_key_refs(union futex_key *key)
 }
 
 /**
- * get_futex_key - Get parameters which are the keys for a futex.
- * @uaddr: virtual address of the futex
- * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
- * @key: address where result is stored.
- * @rw: mapping needs to be read/write (values: VERIFY_READ, VERIFY_WRITE)
+ * get_futex_key() - Get parameters which are the keys for a futex
+ * @uaddr:      virtual address of the futex
+ * @fshared:    0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @key:        address where result is stored.
+ * @rw:         mapping needs to be read/write (values: VERIFY_READ,
+ *              VERIFY_WRITE)
  *
  * Returns a negative error code or 0
  * The key words are stored in *key on success.
@@ -288,8 +289,8 @@ void put_futex_key(int fshared, union futex_key *key)
         drop_futex_key_refs(key);
 }
 
-/*
- * fault_in_user_writeable - fault in user address and verify RW access
+/**
+ * fault_in_user_writeable() - Fault in user address and verify RW access
  * @uaddr:      pointer to faulting user space address
  *
  * Slow path to fixup the fault we just took in the atomic write
@@ -309,8 +310,8 @@ static int fault_in_user_writeable(u32 __user *uaddr)
 
 /**
  * futex_top_waiter() - Return the highest priority waiter on a futex
- * @hb:     the hash bucket the futex_q's reside in
- * @key:    the futex key (to distinguish it from other futex futex_q's)
+ * @hb:         the hash bucket the futex_q's reside in
+ * @key:        the futex key (to distinguish it from other futex futex_q's)
  *
  * Must be called with the hb lock held.
  */
@@ -588,7 +589,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
 }
 
 /**
- * futex_lock_pi_atomic() - atomic work required to acquire a pi aware futex
+ * futex_lock_pi_atomic() - Atomic work required to acquire a pi aware futex
  * @uaddr:              the pi futex user address
  * @hb:                 the pi futex hash bucket
  * @key:                the futex key associated with uaddr and hb
@@ -915,8 +916,8 @@ retry:
         hb1 = hash_futex(&key1);
         hb2 = hash_futex(&key2);
 
-        double_lock_hb(hb1, hb2);
 retry_private:
+        double_lock_hb(hb1, hb2);
         op_ret = futex_atomic_op_inuser(op, uaddr2);
         if (unlikely(op_ret < 0)) {
 
@@ -1011,9 +1012,9 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
 
 /**
  * requeue_pi_wake_futex() - Wake a task that acquired the lock during requeue
- * q:   the futex_q
- * key: the key of the requeue target futex
- * hb:  the hash_bucket of the requeue target futex
+ * @q:          the futex_q
+ * @key:        the key of the requeue target futex
+ * @hb:         the hash_bucket of the requeue target futex
  *
  * During futex_requeue, with requeue_pi=1, it is possible to acquire the
  * target futex if it is uncontended or via a lock steal.  Set the futex_q key
@@ -1350,6 +1351,25 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
         return hb;
 }
 
+static inline void
+queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
+{
+        spin_unlock(&hb->lock);
+        drop_futex_key_refs(&q->key);
+}
+
+/**
+ * queue_me() - Enqueue the futex_q on the futex_hash_bucket
+ * @q:  The futex_q to enqueue
+ * @hb: The destination hash bucket
+ *
+ * The hb->lock must be held by the caller, and is released here. A call to
+ * queue_me() is typically paired with exactly one call to unqueue_me().  The
+ * exceptions involve the PI related operations, which may use unqueue_me_pi()
+ * or nothing if the unqueue is done as part of the wake process and the unqueue
+ * state is implicit in the state of woken task (see futex_wait_requeue_pi() for
+ * an example).
+ */
 static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
 {
         int prio;
@@ -1373,19 +1393,17 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
         spin_unlock(&hb->lock);
 }
 
-static inline void
-queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
-{
-        spin_unlock(&hb->lock);
-        drop_futex_key_refs(&q->key);
-}
-
-/*
- * queue_me and unqueue_me must be called as a pair, each
- * exactly once.  They are called with the hashed spinlock held.
+/**
+ * unqueue_me() - Remove the futex_q from its futex_hash_bucket
+ * @q:  The futex_q to unqueue
+ *
+ * The q->lock_ptr must not be held by the caller. A call to unqueue_me() must
+ * be paired with exactly one earlier call to queue_me().
+ *
+ * Returns:
+ *   1 - if the futex_q was still queued (and we removed unqueued it)
+ *   0 - if the futex_q was already removed by the waking thread
  */
-
-/* Return 1 if we were still queued (ie. 0 means we were woken) */
 static int unqueue_me(struct futex_q *q)
 {
         spinlock_t *lock_ptr;
@@ -1638,17 +1656,14 @@ out:
 static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
                                 struct hrtimer_sleeper *timeout)
 {
-        queue_me(q, hb);
-
         /*
-         * There might have been scheduling since the queue_me(), as we
-         * cannot hold a spinlock across the get_user() in case it
-         * faults, and we cannot just set TASK_INTERRUPTIBLE state when
-         * queueing ourselves into the futex hash. This code thus has to
-         * rely on the futex_wake() code removing us from hash when it
-         * wakes us up.
+         * The task state is guaranteed to be set before another task can
+         * wake it. set_current_state() is implemented using set_mb() and
+         * queue_me() calls spin_unlock() upon completion, both serializing
+         * access to the hash list and forcing another memory barrier.
          */
         set_current_state(TASK_INTERRUPTIBLE);
+        queue_me(q, hb);
 
         /* Arm the timer */
         if (timeout) {
@@ -1658,8 +1673,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
         }
 
         /*
-         * !plist_node_empty() is safe here without any lock.
-         * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
+         * If we have been removed from the hash list, then another task
+         * has tried to wake us, and we can skip the call to schedule().
          */
         if (likely(!plist_node_empty(&q->list))) {
                 /*
@@ -2102,7 +2117,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
                  * Unqueue the futex_q and determine which it was.
                  */
                 plist_del(&q->list, &q->list.plist);
-                drop_futex_key_refs(&q->key);
 
                 if (timeout && !timeout->task)
                         ret = -ETIMEDOUT;
@@ -2114,12 +2128,12 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
 
 /**
  * futex_wait_requeue_pi() - Wait on uaddr and take uaddr2
- * @uaddr:      the futex we initialyl wait on (non-pi)
+ * @uaddr:      the futex we initially wait on (non-pi)
  * @fshared:    whether the futexes are shared (1) or not (0).  They must be
  *              the same type, no requeueing from private to shared, etc.
  * @val:        the expected value of uaddr
  * @abs_time:   absolute timeout
- * @bitset:     32 bit wakeup bitset set by userspace, defaults to all.
+ * @bitset:     32 bit wakeup bitset set by userspace, defaults to all
  * @clockrt:    whether to use CLOCK_REALTIME (1) or CLOCK_MONOTONIC (0)
  * @uaddr2:     the pi futex we will take prior to returning to user-space
  *
@@ -2246,7 +2260,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
                 res = fixup_owner(uaddr2, fshared, &q, !ret);
                 /*
                  * If fixup_owner() returned an error, proprogate that.  If it
-                 * acquired the lock, clear our -ETIMEDOUT or -EINTR.
+                 * acquired the lock, clear -ETIMEDOUT or -EINTR.
                  */
                 if (res)
                         ret = (res < 0) ? res : 0;
@@ -2302,9 +2316,9 @@ out:
  */
 
 /**
- * sys_set_robust_list - set the robust-futex list head of a task
- * @head: pointer to the list-head
- * @len: length of the list-head, as userspace expects
+ * sys_set_robust_list() - Set the robust-futex list head of a task
+ * @head:       pointer to the list-head
+ * @len:        length of the list-head, as userspace expects
  */
 SYSCALL_DEFINE2(set_robust_list, struct robust_list_head __user *, head,
                 size_t, len)
@@ -2323,10 +2337,10 @@ SYSCALL_DEFINE2(set_robust_list, struct robust_list_head __user *, head,
 }
 
 /**
- * sys_get_robust_list - get the robust-futex list head of a task
- * @pid: pid of the process [zero for current task]
- * @head_ptr: pointer to a list-head pointer, the kernel fills it in
- * @len_ptr: pointer to a length field, the kernel fills in the header size
+ * sys_get_robust_list() - Get the robust-futex list head of a task
+ * @pid:        pid of the process [zero for current task]
+ * @head_ptr:   pointer to a list-head pointer, the kernel fills it in
+ * @len_ptr:    pointer to a length field, the kernel fills in the header size
  */
 SYSCALL_DEFINE3(get_robust_list, int, pid,
                 struct robust_list_head __user * __user *, head_ptr,
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index 654efd09f6a9..70a298d6da71 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -34,7 +34,7 @@ config GCOV_KERNEL
 config GCOV_PROFILE_ALL
         bool "Profile entire Kernel"
         depends on GCOV_KERNEL
-        depends on S390 || X86 || (PPC && EXPERIMENTAL)
+        depends on S390 || X86 || (PPC && EXPERIMENTAL) || MICROBLAZE
         default n
         ---help---
         This options activates profiling for the entire kernel.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 05071bf6a37b..3e1c36e7998f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -48,36 +48,7 @@
 
 #include <asm/uaccess.h>
 
-/**
- * ktime_get - get the monotonic time in ktime_t format
- *
- * returns the time in ktime_t format
- */
-ktime_t ktime_get(void)
-{
-        struct timespec now;
-
-        ktime_get_ts(&now);
-
-        return timespec_to_ktime(now);
-}
-EXPORT_SYMBOL_GPL(ktime_get);
-
-/**
- * ktime_get_real - get the real (wall-) time in ktime_t format
- *
- * returns the time in ktime_t format
- */
-ktime_t ktime_get_real(void)
-{
-        struct timespec now;
-
-        getnstimeofday(&now);
-
-        return timespec_to_ktime(now);
-}
-
-EXPORT_SYMBOL_GPL(ktime_get_real);
+#include <trace/events/timer.h>
 
 /*
  * The timer bases:
@@ -106,31 +77,6 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
         }
 };
 
-/**
- * ktime_get_ts - get the monotonic clock in timespec format
- * @ts:         pointer to timespec variable
- *
- * The function calculates the monotonic clock from the realtime
- * clock and the wall_to_monotonic offset and stores the result
- * in normalized timespec format in the variable pointed to by @ts.
- */
-void ktime_get_ts(struct timespec *ts)
-{
-        struct timespec tomono;
-        unsigned long seq;
-
-        do {
-                seq = read_seqbegin(&xtime_lock);
-                getnstimeofday(ts);
-                tomono = wall_to_monotonic;
-
-        } while (read_seqretry(&xtime_lock, seq));
-
-        set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
-                                ts->tv_nsec + tomono.tv_nsec);
-}
-EXPORT_SYMBOL_GPL(ktime_get_ts);
-
 /*
  * Get the coarse grained time at the softirq based on xtime and
  * wall_to_monotonic.
@@ -498,6 +444,26 @@ static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
 #endif
 
+static inline void
+debug_init(struct hrtimer *timer, clockid_t clockid,
+           enum hrtimer_mode mode)
+{
+        debug_hrtimer_init(timer);
+        trace_hrtimer_init(timer, clockid, mode);
+}
+
+static inline void debug_activate(struct hrtimer *timer)
+{
+        debug_hrtimer_activate(timer);
+        trace_hrtimer_start(timer);
+}
+
+static inline void debug_deactivate(struct hrtimer *timer)
+{
+        debug_hrtimer_deactivate(timer);
+        trace_hrtimer_cancel(timer);
+}
+
 /* High resolution timer related functions */
 #ifdef CONFIG_HIGH_RES_TIMERS
 
@@ -543,13 +509,14 @@ static inline int hrtimer_hres_active(void)
  * next event
  * Called with interrupts disabled and base->lock held
  */
-static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
+static void
+hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
 {
         int i;
         struct hrtimer_clock_base *base = cpu_base->clock_base;
-        ktime_t expires;
+        ktime_t expires, expires_next;
 
-        cpu_base->expires_next.tv64 = KTIME_MAX;
+        expires_next.tv64 = KTIME_MAX;
 
         for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
                 struct hrtimer *timer;
@@ -565,10 +532,15 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
                  */
                 if (expires.tv64 < 0)
                         expires.tv64 = 0;
-                if (expires.tv64 < cpu_base->expires_next.tv64)
-                        cpu_base->expires_next = expires;
+                if (expires.tv64 < expires_next.tv64)
+                        expires_next = expires;
         }
 
+        if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
+                return;
+
+        cpu_base->expires_next.tv64 = expires_next.tv64;
+
         if (cpu_base->expires_next.tv64 != KTIME_MAX)
                 tick_program_event(cpu_base->expires_next, 1);
 }
@@ -651,7 +623,7 @@ static void retrigger_next_event(void *arg)
         base->clock_base[CLOCK_REALTIME].offset =
                 timespec_to_ktime(realtime_offset);
 
-        hrtimer_force_reprogram(base);
+        hrtimer_force_reprogram(base, 0);
         spin_unlock(&base->lock);
 }
 
@@ -754,8 +726,6 @@ static int hrtimer_switch_to_hres(void)
         /* "Retrigger" the interrupt to get things going */
         retrigger_next_event(NULL);
         local_irq_restore(flags);
-        printk(KERN_DEBUG "Switched to high resolution mode on CPU %d\n",
-               smp_processor_id());
         return 1;
 }
 
@@ -764,7 +734,8 @@ static int hrtimer_switch_to_hres(void)
 static inline int hrtimer_hres_active(void) { return 0; }
 static inline int hrtimer_is_hres_enabled(void) { return 0; }
 static inline int hrtimer_switch_to_hres(void) { return 0; }
-static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
+static inline void
+hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
                                             struct hrtimer_clock_base *base,
                                             int wakeup)
@@ -854,7 +825,7 @@ static int enqueue_hrtimer(struct hrtimer *timer,
         struct hrtimer *entry;
         int leftmost = 1;
 
-        debug_hrtimer_activate(timer);
+        debug_activate(timer);
 
         /*
          * Find the right place in the rbtree:
@@ -907,19 +878,29 @@ static void __remove_hrtimer(struct hrtimer *timer,
                              struct hrtimer_clock_base *base,
                              unsigned long newstate, int reprogram)
 {
-        if (timer->state & HRTIMER_STATE_ENQUEUED) {
-                /*
-                 * Remove the timer from the rbtree and replace the
-                 * first entry pointer if necessary.
-                 */
-                if (base->first == &timer->node) {
-                        base->first = rb_next(&timer->node);
-                        /* Reprogram the clock event device. if enabled */
-                        if (reprogram && hrtimer_hres_active())
-                                hrtimer_force_reprogram(base->cpu_base);
+        if (!(timer->state & HRTIMER_STATE_ENQUEUED))
+                goto out;
+
+        /*
+         * Remove the timer from the rbtree and replace the first
+         * entry pointer if necessary.
+         */
+        if (base->first == &timer->node) {
+                base->first = rb_next(&timer->node);
+#ifdef CONFIG_HIGH_RES_TIMERS
+                /* Reprogram the clock event device. if enabled */
+                if (reprogram && hrtimer_hres_active()) {
+                        ktime_t expires;
+
+                        expires = ktime_sub(hrtimer_get_expires(timer),
+                                            base->offset);
+                        if (base->cpu_base->expires_next.tv64 == expires.tv64)
+                                hrtimer_force_reprogram(base->cpu_base, 1);
                 }
-                rb_erase(&timer->node, &base->active);
+#endif
         }
+        rb_erase(&timer->node, &base->active);
+out:
         timer->state = newstate;
 }
 
@@ -940,7 +921,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
                  * reprogramming happens in the interrupt handler. This is a
                  * rare case and less expensive than a smp call.
                  */
-                debug_hrtimer_deactivate(timer);
+                debug_deactivate(timer);
                 timer_stats_hrtimer_clear_start_info(timer);
                 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
                 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
@@ -1155,7 +1136,6 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
                 clock_id = CLOCK_MONOTONIC;
 
         timer->base = &cpu_base->clock_base[clock_id];
-        INIT_LIST_HEAD(&timer->cb_entry);
         hrtimer_init_timer_hres(timer);
 
 #ifdef CONFIG_TIMER_STATS
@@ -1174,7 +1154,7 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
                   enum hrtimer_mode mode)
 {
-        debug_hrtimer_init(timer);
+        debug_init(timer, clock_id, mode);
         __hrtimer_init(timer, clock_id, mode);
 }
 EXPORT_SYMBOL_GPL(hrtimer_init);
@@ -1198,7 +1178,7 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_res);
 
-static void __run_hrtimer(struct hrtimer *timer)
+static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
 {
         struct hrtimer_clock_base *base = timer->base;
         struct hrtimer_cpu_base *cpu_base = base->cpu_base;
@@ -1207,7 +1187,7 @@ static void __run_hrtimer(struct hrtimer *timer)
 
         WARN_ON(!irqs_disabled());
 
-        debug_hrtimer_deactivate(timer);
+        debug_deactivate(timer);
         __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
         timer_stats_account_hrtimer(timer);
         fn = timer->function;
@@ -1218,7 +1198,9 @@ static void __run_hrtimer(struct hrtimer *timer)
          * the timer base.
          */
         spin_unlock(&cpu_base->lock);
+        trace_hrtimer_expire_entry(timer, now);
         restart = fn(timer);
+        trace_hrtimer_expire_exit(timer);
         spin_lock(&cpu_base->lock);
 
         /*
@@ -1329,7 +1311,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
                                 break;
                         }
 
-                        __run_hrtimer(timer);
+                        __run_hrtimer(timer, &basenow);
                 }
                 base++;
         }
@@ -1451,7 +1433,7 @@ void hrtimer_run_queues(void)
                                         hrtimer_get_expires_tv64(timer))
                                 break;
 
-                        __run_hrtimer(timer);
+                        __run_hrtimer(timer, &base->softirq_time);
                 }
                 spin_unlock(&cpu_base->lock);
         }
@@ -1628,7 +1610,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
         while ((node = rb_first(&old_base->active))) {
                 timer = rb_entry(node, struct hrtimer, node);
                 BUG_ON(hrtimer_callback_running(timer));
-                debug_hrtimer_deactivate(timer);
+                debug_deactivate(timer);
 
                 /*
                  * Mark it as STATE_MIGRATE not INACTIVE otherwise the
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 022a4927b785..d4e841747400 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -171,12 +171,12 @@ static unsigned long timeout_jiffies(unsigned long timeout)
  * Process updating of timeout sysctl
  */
 int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
-                                  struct file *filp, void __user *buffer,
+                                  void __user *buffer,
                                   size_t *lenp, loff_t *ppos)
 {
         int ret;
 
-        ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos);
+        ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 
         if (ret || !write)
                 goto out;
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index a81cf80554db..17c71bb565c6 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/irq.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/random.h>
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 58762f7077ec..b03451ede528 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -12,6 +12,7 @@
 #include <linux/time.h>
 #include <linux/posix-timers.h>
 #include <linux/hrtimer.h>
+#include <trace/events/timer.h>
 
 #include <asm/uaccess.h>
 
@@ -41,10 +42,43 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
         return ktime_to_timeval(rem);
 }
 
+static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+                           struct itimerval *const value)
+{
+        cputime_t cval, cinterval;
+        struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+        spin_lock_irq(&tsk->sighand->siglock);
+
+        cval = it->expires;
+        cinterval = it->incr;
+        if (!cputime_eq(cval, cputime_zero)) {
+                struct task_cputime cputime;
+                cputime_t t;
+
+                thread_group_cputimer(tsk, &cputime);
+                if (clock_id == CPUCLOCK_PROF)
+                        t = cputime_add(cputime.utime, cputime.stime);
+                else
+                        /* CPUCLOCK_VIRT */
+                        t = cputime.utime;
+
+                if (cputime_le(cval, t))
+                        /* about to fire */
+                        cval = cputime_one_jiffy;
+                else
+                        cval = cputime_sub(cval, t);
+        }
+
+        spin_unlock_irq(&tsk->sighand->siglock);
+
+        cputime_to_timeval(cval, &value->it_value);
+        cputime_to_timeval(cinterval, &value->it_interval);
+}
+
 int do_getitimer(int which, struct itimerval *value)
 {
         struct task_struct *tsk = current;
-        cputime_t cinterval, cval;
 
         switch (which) {
         case ITIMER_REAL:
@@ -55,44 +89,10 @@ int do_getitimer(int which, struct itimerval *value)
                 spin_unlock_irq(&tsk->sighand->siglock);
                 break;
         case ITIMER_VIRTUAL:
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_virt_expires;
-                cinterval = tsk->signal->it_virt_incr;
-                if (!cputime_eq(cval, cputime_zero)) {
-                        struct task_cputime cputime;
-                        cputime_t utime;
-
-                        thread_group_cputimer(tsk, &cputime);
-                        utime = cputime.utime;
-                        if (cputime_le(cval, utime)) { /* about to fire */
-                                cval = jiffies_to_cputime(1);
-                        } else {
-                                cval = cputime_sub(cval, utime);
-                        }
-                }
-                spin_unlock_irq(&tsk->sighand->siglock);
-                cputime_to_timeval(cval, &value->it_value);
-                cputime_to_timeval(cinterval, &value->it_interval);
+                get_cpu_itimer(tsk, CPUCLOCK_VIRT, value);
                 break;
         case ITIMER_PROF:
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_prof_expires;
-                cinterval = tsk->signal->it_prof_incr;
-                if (!cputime_eq(cval, cputime_zero)) {
-                        struct task_cputime times;
-                        cputime_t ptime;
-
-                        thread_group_cputimer(tsk, &times);
-                        ptime = cputime_add(times.utime, times.stime);
-                        if (cputime_le(cval, ptime)) { /* about to fire */
-                                cval = jiffies_to_cputime(1);
-                        } else {
-                                cval = cputime_sub(cval, ptime);
-                        }
-                }
-                spin_unlock_irq(&tsk->sighand->siglock);
-                cputime_to_timeval(cval, &value->it_value);
-                cputime_to_timeval(cinterval, &value->it_interval);
+                get_cpu_itimer(tsk, CPUCLOCK_PROF, value);
                 break;
         default:
                 return(-EINVAL);
@@ -123,11 +123,62 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
         struct signal_struct *sig =
                 container_of(timer, struct signal_struct, real_timer);
 
+        trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0);
         kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);
 
         return HRTIMER_NORESTART;
 }
 
+static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns)
+{
+        struct timespec ts;
+        s64 cpu_ns;
+
+        cputime_to_timespec(ct, &ts);
+        cpu_ns = timespec_to_ns(&ts);
+
+        return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns;
+}
+
+static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+                           const struct itimerval *const value,
+                           struct itimerval *const ovalue)
+{
+        cputime_t cval, nval, cinterval, ninterval;
+        s64 ns_ninterval, ns_nval;
+        struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+        nval = timeval_to_cputime(&value->it_value);
+        ns_nval = timeval_to_ns(&value->it_value);
+        ninterval = timeval_to_cputime(&value->it_interval);
+        ns_ninterval = timeval_to_ns(&value->it_interval);
+
+        it->incr_error = cputime_sub_ns(ninterval, ns_ninterval);
+        it->error = cputime_sub_ns(nval, ns_nval);
+
+        spin_lock_irq(&tsk->sighand->siglock);
+
+        cval = it->expires;
+        cinterval = it->incr;
+        if (!cputime_eq(cval, cputime_zero) ||
+            !cputime_eq(nval, cputime_zero)) {
+                if (cputime_gt(nval, cputime_zero))
+                        nval = cputime_add(nval, cputime_one_jiffy);
+                set_process_cpu_timer(tsk, clock_id, &nval, &cval);
+        }
+        it->expires = nval;
+        it->incr = ninterval;
+        trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
+                           ITIMER_VIRTUAL : ITIMER_PROF, value, nval);
+
+        spin_unlock_irq(&tsk->sighand->siglock);
+
+        if (ovalue) {
+                cputime_to_timeval(cval, &ovalue->it_value);
+                cputime_to_timeval(cinterval, &ovalue->it_interval);
+        }
+}
+
 /*
  * Returns true if the timeval is in canonical form
  */
@@ -139,7 +190,6 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
         struct task_struct *tsk = current;
         struct hrtimer *timer;
         ktime_t expires;
-        cputime_t cval, cinterval, nval, ninterval;
 
         /*
          * Validate the timevals in value.
@@ -171,51 +221,14 @@ again:
                 } else
                         tsk->signal->it_real_incr.tv64 = 0;
 
+                trace_itimer_state(ITIMER_REAL, value, 0);
                 spin_unlock_irq(&tsk->sighand->siglock);
                 break;
         case ITIMER_VIRTUAL:
-                nval = timeval_to_cputime(&value->it_value);
-                ninterval = timeval_to_cputime(&value->it_interval);
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_virt_expires;
-                cinterval = tsk->signal->it_virt_incr;
-                if (!cputime_eq(cval, cputime_zero) ||
-                    !cputime_eq(nval, cputime_zero)) {
-                        if (cputime_gt(nval, cputime_zero))
-                                nval = cputime_add(nval,
-                                                   jiffies_to_cputime(1));
-                        set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
-                                              &nval, &cval);
-                }
-                tsk->signal->it_virt_expires = nval;
-                tsk->signal->it_virt_incr = ninterval;
-                spin_unlock_irq(&tsk->sighand->siglock);
-                if (ovalue) {
-                        cputime_to_timeval(cval, &ovalue->it_value);
-                        cputime_to_timeval(cinterval, &ovalue->it_interval);
-                }
+                set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue);
                 break;
         case ITIMER_PROF:
-                nval = timeval_to_cputime(&value->it_value);
-                ninterval = timeval_to_cputime(&value->it_interval);
-                spin_lock_irq(&tsk->sighand->siglock);
-                cval = tsk->signal->it_prof_expires;
-                cinterval = tsk->signal->it_prof_incr;
-                if (!cputime_eq(cval, cputime_zero) ||
-                    !cputime_eq(nval, cputime_zero)) {
-                        if (cputime_gt(nval, cputime_zero))
-                                nval = cputime_add(nval,
-                                                   jiffies_to_cputime(1));
-                        set_process_cpu_timer(tsk, CPUCLOCK_PROF,
-                                              &nval, &cval);
-                }
-                tsk->signal->it_prof_expires = nval;
-                tsk->signal->it_prof_incr = ninterval;
-                spin_unlock_irq(&tsk->sighand->siglock);
-                if (ovalue) {
-                        cputime_to_timeval(cval, &ovalue->it_value);
-                        cputime_to_timeval(cinterval, &ovalue->it_interval);
-                }
+                set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue);
                 break;
         default:
                 return -EINVAL;
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 3a29dbe7898e..8b6b8b697c68 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -59,7 +59,8 @@ static inline int is_kernel_inittext(unsigned long addr)
 
 static inline int is_kernel_text(unsigned long addr)
 {
-        if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
+        if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
+            arch_is_kernel_text(addr))
                 return 1;
         return in_gate_area_no_task(addr);
 }
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 26539e3228e5..3765ff3c1bbe 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -117,7 +117,7 @@ EXPORT_SYMBOL(kfifo_free);
  * writer, you don't need extra locking to use these functions.
  */
 unsigned int __kfifo_put(struct kfifo *fifo,
-                         unsigned char *buffer, unsigned int len)
+                        const unsigned char *buffer, unsigned int len)
 {
         unsigned int l;
 
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ef177d653b2c..5240d75f4c60 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1321,7 +1321,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
         return 0;
 }
 
-static struct seq_operations kprobes_seq_ops = {
+static const struct seq_operations kprobes_seq_ops = {
         .start = kprobe_seq_start,
         .next  = kprobe_seq_next,
         .stop  = kprobe_seq_stop,
@@ -1333,7 +1333,7 @@ static int __kprobes kprobes_open(struct inode *inode, struct file *filp)
         return seq_open(filp, &kprobes_seq_ops);
 }
 
-static struct file_operations debugfs_kprobes_operations = {
+static const struct file_operations debugfs_kprobes_operations = {
         .open           = kprobes_open,
         .read           = seq_read,
         .llseek         = seq_lseek,
@@ -1515,7 +1515,7 @@ static ssize_t write_enabled_file_bool(struct file *file,
         return count;
 }
 
-static struct file_operations fops_kp = {
+static const struct file_operations fops_kp = {
         .read =         read_enabled_file_bool,
         .write =        write_enabled_file_bool,
 };
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f74d2d7aa605..9af56723c096 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -142,6 +142,11 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 #ifdef CONFIG_LOCK_STAT
 static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
 
+static inline u64 lockstat_clock(void)
+{
+        return cpu_clock(smp_processor_id());
+}
+
 static int lock_point(unsigned long points[], unsigned long ip)
 {
         int i;
@@ -158,7 +163,7 @@ static int lock_point(unsigned long points[], unsigned long ip)
         return i;
 }
 
-static void lock_time_inc(struct lock_time *lt, s64 time)
+static void lock_time_inc(struct lock_time *lt, u64 time)
 {
         if (time > lt->max)
                 lt->max = time;
@@ -234,12 +239,12 @@ static void put_lock_stats(struct lock_class_stats *stats)
 static void lock_release_holdtime(struct held_lock *hlock)
 {
         struct lock_class_stats *stats;
-        s64 holdtime;
+        u64 holdtime;
 
         if (!lock_stat)
                 return;
 
-        holdtime = sched_clock() - hlock->holdtime_stamp;
+        holdtime = lockstat_clock() - hlock->holdtime_stamp;
 
         stats = get_lock_stats(hlock_class(hlock));
         if (hlock->read)
@@ -578,6 +583,9 @@ static int static_obj(void *obj)
         if ((addr >= start) && (addr < end))
                 return 1;
 
+        if (arch_is_kernel_data(addr))
+                return 1;
+
 #ifdef CONFIG_SMP
         /*
          * percpu var?
@@ -2789,7 +2797,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         hlock->references = references;
 #ifdef CONFIG_LOCK_STAT
         hlock->waittime_stamp = 0;
-        hlock->holdtime_stamp = sched_clock();
+        hlock->holdtime_stamp = lockstat_clock();
 #endif
 
         if (check == 2 && !mark_irqflags(curr, hlock))
@@ -3319,7 +3327,7 @@ found_it:
         if (hlock->instance != lock)
                 return;
 
-        hlock->waittime_stamp = sched_clock();
+        hlock->waittime_stamp = lockstat_clock();
 
         contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
         contending_point = lock_point(hlock_class(hlock)->contending_point,
@@ -3342,8 +3350,7 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
         struct held_lock *hlock, *prev_hlock;
         struct lock_class_stats *stats;
         unsigned int depth;
-        u64 now;
-        s64 waittime = 0;
+        u64 now, waittime = 0;
         int i, cpu;
 
         depth = curr->lockdep_depth;
@@ -3371,7 +3378,7 @@ found_it:
 
         cpu = smp_processor_id();
         if (hlock->waittime_stamp) {
-                now = sched_clock();
+                now = lockstat_clock();
                 waittime = now - hlock->waittime_stamp;
                 hlock->holdtime_stamp = now;
         }
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index d4b3dbc79fdb..d4aba4f3584c 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -594,7 +594,7 @@ static int ls_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations lockstat_ops = {
+static const struct seq_operations lockstat_ops = {
         .start  = ls_start,
         .next   = ls_next,
         .stop   = ls_stop,
diff --git a/kernel/marker.c b/kernel/marker.c
deleted file mode 100644
index ea54f2647868..000000000000
--- a/kernel/marker.c
+++ /dev/null
@@ -1,930 +0,0 @@
-/*
- * Copyright (C) 2007 Mathieu Desnoyers
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/types.h>
-#include <linux/jhash.h>
-#include <linux/list.h>
-#include <linux/rcupdate.h>
-#include <linux/marker.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-
-extern struct marker __start___markers[];
-extern struct marker __stop___markers[];
-
-/* Set to 1 to enable marker debug output */
-static const int marker_debug;
-
-/*
- * markers_mutex nests inside module_mutex. Markers mutex protects the builtin
- * and module markers and the hash table.
- */
-static DEFINE_MUTEX(markers_mutex);
-
-/*
- * Marker hash table, containing the active markers.
- * Protected by module_mutex.
- */
-#define MARKER_HASH_BITS 6
-#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS)
-static struct hlist_head marker_table[MARKER_TABLE_SIZE];
-
-/*
- * Note about RCU :
- * It is used to make sure every handler has finished using its private data
- * between two consecutive operation (add or remove) on a given marker.  It is
- * also used to delay the free of multiple probes array until a quiescent state
- * is reached.
- * marker entries modifications are protected by the markers_mutex.
- */
-struct marker_entry {
-        struct hlist_node hlist;
-        char *format;
-                        /* Probe wrapper */
-        void (*call)(const struct marker *mdata, void *call_private, ...);
-        struct marker_probe_closure single;
-        struct marker_probe_closure *multi;
-        int refcount;   /* Number of times armed. 0 if disarmed. */
-        struct rcu_head rcu;
-        void *oldptr;
-        int rcu_pending;
-        unsigned char ptype:1;
-        unsigned char format_allocated:1;
-        char name[0];   /* Contains name'\0'format'\0' */
-};
-
-/**
- * __mark_empty_function - Empty probe callback
- * @probe_private: probe private data
- * @call_private: call site private data
- * @fmt: format string
- * @...: variable argument list
- *
- * Empty callback provided as a probe to the markers. By providing this to a
- * disabled marker, we make sure the  execution flow is always valid even
- * though the function pointer change and the marker enabling are two distinct
- * operations that modifies the execution flow of preemptible code.
- */
-notrace void __mark_empty_function(void *probe_private, void *call_private,
-        const char *fmt, va_list *args)
-{
-}
-EXPORT_SYMBOL_GPL(__mark_empty_function);
-
-/*
- * marker_probe_cb Callback that prepares the variable argument list for probes.
- * @mdata: pointer of type struct marker
- * @call_private: caller site private data
- * @...:  Variable argument list.
- *
- * Since we do not use "typical" pointer based RCU in the 1 argument case, we
- * need to put a full smp_rmb() in this branch. This is why we do not use
- * rcu_dereference() for the pointer read.
- */
-notrace void marker_probe_cb(const struct marker *mdata,
-                void *call_private, ...)
-{
-        va_list args;
-        char ptype;
-
-        /*
-         * rcu_read_lock_sched does two things : disabling preemption to make
-         * sure the teardown of the callbacks can be done correctly when they
-         * are in modules and they insure RCU read coherency.
-         */
-        rcu_read_lock_sched_notrace();
-        ptype = mdata->ptype;
-        if (likely(!ptype)) {
-                marker_probe_func *func;
-                /* Must read the ptype before ptr. They are not data dependant,
-                 * so we put an explicit smp_rmb() here. */
-                smp_rmb();
-                func = mdata->single.func;
-                /* Must read the ptr before private data. They are not data
-                 * dependant, so we put an explicit smp_rmb() here. */
-                smp_rmb();
-                va_start(args, call_private);
-                func(mdata->single.probe_private, call_private, mdata->format,
-                        &args);
-                va_end(args);
-        } else {
-                struct marker_probe_closure *multi;
-                int i;
-                /*
-                 * Read mdata->ptype before mdata->multi.
-                 */
-                smp_rmb();
-                multi = mdata->multi;
-                /*
-                 * multi points to an array, therefore accessing the array
-                 * depends on reading multi. However, even in this case,
-                 * we must insure that the pointer is read _before_ the array
-                 * data. Same as rcu_dereference, but we need a full smp_rmb()
-                 * in the fast path, so put the explicit barrier here.
-                 */
-                smp_read_barrier_depends();
-                for (i = 0; multi[i].func; i++) {
-                        va_start(args, call_private);
-                        multi[i].func(multi[i].probe_private, call_private,
-                                mdata->format, &args);
-                        va_end(args);
-                }
-        }
-        rcu_read_unlock_sched_notrace();
-}
-EXPORT_SYMBOL_GPL(marker_probe_cb);
-
-/*
- * marker_probe_cb Callback that does not prepare the variable argument list.
- * @mdata: pointer of type struct marker
- * @call_private: caller site private data
- * @...:  Variable argument list.
- *
- * Should be connected to markers "MARK_NOARGS".
- */
-static notrace void marker_probe_cb_noarg(const struct marker *mdata,
-                void *call_private, ...)
-{
-        va_list args;   /* not initialized */
-        char ptype;
-
-        rcu_read_lock_sched_notrace();
-        ptype = mdata->ptype;
-        if (likely(!ptype)) {
-                marker_probe_func *func;
-                /* Must read the ptype before ptr. They are not data dependant,
-                 * so we put an explicit smp_rmb() here. */
-                smp_rmb();
-                func = mdata->single.func;
-                /* Must read the ptr before private data. They are not data
-                 * dependant, so we put an explicit smp_rmb() here. */
-                smp_rmb();
-                func(mdata->single.probe_private, call_private, mdata->format,
-                        &args);
-        } else {
-                struct marker_probe_closure *multi;
-                int i;
-                /*
-                 * Read mdata->ptype before mdata->multi.
-                 */
-                smp_rmb();
-                multi = mdata->multi;
-                /*
-                 * multi points to an array, therefore accessing the array
-                 * depends on reading multi. However, even in this case,
-                 * we must insure that the pointer is read _before_ the array
-                 * data. Same as rcu_dereference, but we need a full smp_rmb()
-                 * in the fast path, so put the explicit barrier here.
-                 */
-                smp_read_barrier_depends();
-                for (i = 0; multi[i].func; i++)
-                        multi[i].func(multi[i].probe_private, call_private,
-                                mdata->format, &args);
-        }
-        rcu_read_unlock_sched_notrace();
-}
-
-static void free_old_closure(struct rcu_head *head)
-{
-        struct marker_entry *entry = container_of(head,
-                struct marker_entry, rcu);
-        kfree(entry->oldptr);
-        /* Make sure we free the data before setting the pending flag to 0 */
-        smp_wmb();
-        entry->rcu_pending = 0;
-}
-
-static void debug_print_probes(struct marker_entry *entry)
-{
-        int i;
-
-        if (!marker_debug)
-                return;
-
-        if (!entry->ptype) {
-                printk(KERN_DEBUG "Single probe : %p %p\n",
-                        entry->single.func,
-                        entry->single.probe_private);
-        } else {
-                for (i = 0; entry->multi[i].func; i++)
-                        printk(KERN_DEBUG "Multi probe %d : %p %p\n", i,
-                                entry->multi[i].func,
-                                entry->multi[i].probe_private);
-        }
-}
-
-static struct marker_probe_closure *
-marker_entry_add_probe(struct marker_entry *entry,
-                marker_probe_func *probe, void *probe_private)
-{
-        int nr_probes = 0;
-        struct marker_probe_closure *old, *new;
-
-        WARN_ON(!probe);
-
-        debug_print_probes(entry);
-        old = entry->multi;
-        if (!entry->ptype) {
-                if (entry->single.func == probe &&
-                                entry->single.probe_private == probe_private)
-                        return ERR_PTR(-EBUSY);
-                if (entry->single.func == __mark_empty_function) {
-                        /* 0 -> 1 probes */
-                        entry->single.func = probe;
-                        entry->single.probe_private = probe_private;
-                        entry->refcount = 1;
-                        entry->ptype = 0;
-                        debug_print_probes(entry);
-                        return NULL;
-                } else {
-                        /* 1 -> 2 probes */
-                        nr_probes = 1;
-                        old = NULL;
-                }
-        } else {
-                /* (N -> N+1), (N != 0, 1) probes */
-                for (nr_probes = 0; old[nr_probes].func; nr_probes++)
-                        if (old[nr_probes].func == probe
-                                        && old[nr_probes].probe_private
-                                                == probe_private)
-                                return ERR_PTR(-EBUSY);
-        }
-        /* + 2 : one for new probe, one for NULL func */
-        new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure),
-                        GFP_KERNEL);
-        if (new == NULL)
-                return ERR_PTR(-ENOMEM);
-        if (!old)
-                new[0] = entry->single;
-        else
-                memcpy(new, old,
-                        nr_probes * sizeof(struct marker_probe_closure));
-        new[nr_probes].func = probe;
-        new[nr_probes].probe_private = probe_private;
-        entry->refcount = nr_probes + 1;
-        entry->multi = new;
-        entry->ptype = 1;
-        debug_print_probes(entry);
-        return old;
-}
-
-static struct marker_probe_closure *
-marker_entry_remove_probe(struct marker_entry *entry,
-                marker_probe_func *probe, void *probe_private)
-{
-        int nr_probes = 0, nr_del = 0, i;
-        struct marker_probe_closure *old, *new;
-
-        old = entry->multi;
-
-        debug_print_probes(entry);
-        if (!entry->ptype) {
-                /* 0 -> N is an error */
-                WARN_ON(entry->single.func == __mark_empty_function);
-                /* 1 -> 0 probes */
-                WARN_ON(probe && entry->single.func != probe);
-                WARN_ON(entry->single.probe_private != probe_private);
-                entry->single.func = __mark_empty_function;
-                entry->refcount = 0;
-                entry->ptype = 0;
-                debug_print_probes(entry);
-                return NULL;
-        } else {
-                /* (N -> M), (N > 1, M >= 0) probes */
-                for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
-                        if ((!probe || old[nr_probes].func == probe)
-                                        && old[nr_probes].probe_private
-                                                == probe_private)
-                                nr_del++;
-                }
-        }
-
-        if (nr_probes - nr_del == 0) {
-                /* N -> 0, (N > 1) */
-                entry->single.func = __mark_empty_function;
-                entry->refcount = 0;
-                entry->ptype = 0;
-        } else if (nr_probes - nr_del == 1) {
-                /* N -> 1, (N > 1) */
-                for (i = 0; old[i].func; i++)
-                        if ((probe && old[i].func != probe) ||
-                                        old[i].probe_private != probe_private)
-                                entry->single = old[i];
-                entry->refcount = 1;
-                entry->ptype = 0;
-        } else {
-                int j = 0;
-                /* N -> M, (N > 1, M > 1) */
-                /* + 1 for NULL */
-                new = kzalloc((nr_probes - nr_del + 1)
-                        * sizeof(struct marker_probe_closure), GFP_KERNEL);
-                if (new == NULL)
-                        return ERR_PTR(-ENOMEM);
-                for (i = 0; old[i].func; i++)
-                        if ((probe && old[i].func != probe) ||
-                                        old[i].probe_private != probe_private)
-                                new[j++] = old[i];
-                entry->refcount = nr_probes - nr_del;
-                entry->ptype = 1;
-                entry->multi = new;
-        }
-        debug_print_probes(entry);
-        return old;
-}
-
-/*
- * Get marker if the marker is present in the marker hash table.
- * Must be called with markers_mutex held.
- * Returns NULL if not present.
- */
-static struct marker_entry *get_marker(const char *name)
-{
-        struct hlist_head *head;
-        struct hlist_node *node;
-        struct marker_entry *e;
-        u32 hash = jhash(name, strlen(name), 0);
-
-        head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-        hlist_for_each_entry(e, node, head, hlist) {
-                if (!strcmp(name, e->name))
-                        return e;
-        }
-        return NULL;
-}
-
-/*
- * Add the marker to the marker hash table. Must be called with markers_mutex
- * held.
- */
-static struct marker_entry *add_marker(const char *name, const char *format)
-{
-        struct hlist_head *head;
-        struct hlist_node *node;
-        struct marker_entry *e;
-        size_t name_len = strlen(name) + 1;
-        size_t format_len = 0;
-        u32 hash = jhash(name, name_len-1, 0);
-
-        if (format)
-                format_len = strlen(format) + 1;
-        head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-        hlist_for_each_entry(e, node, head, hlist) {
-                if (!strcmp(name, e->name)) {
-                        printk(KERN_NOTICE
-                                "Marker %s busy\n", name);
-                        return ERR_PTR(-EBUSY); /* Already there */
-                }
-        }
-        /*
-         * Using kmalloc here to allocate a variable length element. Could
-         * cause some memory fragmentation if overused.
-         */
-        e = kmalloc(sizeof(struct marker_entry) + name_len + format_len,
-                        GFP_KERNEL);
-        if (!e)
-                return ERR_PTR(-ENOMEM);
-        memcpy(&e->name[0], name, name_len);
-        if (format) {
-                e->format = &e->name[name_len];
-                memcpy(e->format, format, format_len);
-                if (strcmp(e->format, MARK_NOARGS) == 0)
-                        e->call = marker_probe_cb_noarg;
-                else
-                        e->call = marker_probe_cb;
-                trace_mark(core_marker_format, "name %s format %s",
-                                e->name, e->format);
-        } else {
-                e->format = NULL;
-                e->call = marker_probe_cb;
-        }
-        e->single.func = __mark_empty_function;
-        e->single.probe_private = NULL;
-        e->multi = NULL;
-        e->ptype = 0;
-        e->format_allocated = 0;
-        e->refcount = 0;
-        e->rcu_pending = 0;
-        hlist_add_head(&e->hlist, head);
-        return e;
-}
-
-/*
- * Remove the marker from the marker hash table. Must be called with mutex_lock
- * held.
- */
-static int remove_marker(const char *name)
-{
-        struct hlist_head *head;
-        struct hlist_node *node;
-        struct marker_entry *e;
-        int found = 0;
-        size_t len = strlen(name) + 1;
-        u32 hash = jhash(name, len-1, 0);
-
-        head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-        hlist_for_each_entry(e, node, head, hlist) {
-                if (!strcmp(name, e->name)) {
-                        found = 1;
-                        break;
-                }
-        }
-        if (!found)
-                return -ENOENT;
-        if (e->single.func != __mark_empty_function)
-                return -EBUSY;
-        hlist_del(&e->hlist);
-        if (e->format_allocated)
-                kfree(e->format);
-        /* Make sure the call_rcu has been executed */
-        if (e->rcu_pending)
-                rcu_barrier_sched();
-        kfree(e);
-        return 0;
-}
-
-/*
- * Set the mark_entry format to the format found in the element.
- */
-static int marker_set_format(struct marker_entry *entry, const char *format)
-{
-        entry->format = kstrdup(format, GFP_KERNEL);
-        if (!entry->format)
-                return -ENOMEM;
-        entry->format_allocated = 1;
-
-        trace_mark(core_marker_format, "name %s format %s",
-                        entry->name, entry->format);
-        return 0;
-}
-
-/*
- * Sets the probe callback corresponding to one marker.
- */
-static int set_marker(struct marker_entry *entry, struct marker *elem,
-                int active)
-{
-        int ret = 0;
-        WARN_ON(strcmp(entry->name, elem->name) != 0);
-
-        if (entry->format) {
-                if (strcmp(entry->format, elem->format) != 0) {
-                        printk(KERN_NOTICE
-                                "Format mismatch for probe %s "
-                                "(%s), marker (%s)\n",
-                                entry->name,
-                                entry->format,
-                                elem->format);
-                        return -EPERM;
-                }
-        } else {
-                ret = marker_set_format(entry, elem->format);
-                if (ret)
-                        return ret;
-        }
-
-        /*
-         * probe_cb setup (statically known) is done here. It is
-         * asynchronous with the rest of execution, therefore we only
-         * pass from a "safe" callback (with argument) to an "unsafe"
-         * callback (does not set arguments).
-         */
-        elem->call = entry->call;
-        /*
-         * Sanity check :
-         * We only update the single probe private data when the ptr is
-         * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1)
-         */
-        WARN_ON(elem->single.func != __mark_empty_function
-                && elem->single.probe_private != entry->single.probe_private
-                && !elem->ptype);
-        elem->single.probe_private = entry->single.probe_private;
-        /*
-         * Make sure the private data is valid when we update the
-         * single probe ptr.
-         */
-        smp_wmb();
-        elem->single.func = entry->single.func;
-        /*
-         * We also make sure that the new probe callbacks array is consistent
-         * before setting a pointer to it.
-         */
-        rcu_assign_pointer(elem->multi, entry->multi);
-        /*
-         * Update the function or multi probe array pointer before setting the
-         * ptype.
-         */
-        smp_wmb();
-        elem->ptype = entry->ptype;
-
-        if (elem->tp_name && (active ^ elem->state)) {
-                WARN_ON(!elem->tp_cb);
-                /*
-                 * It is ok to directly call the probe registration because type
-                 * checking has been done in the __trace_mark_tp() macro.
-                 */
-
-                if (active) {
-                        /*
-                         * try_module_get should always succeed because we hold
-                         * lock_module() to get the tp_cb address.
-                         */
-                        ret = try_module_get(__module_text_address(
-                                (unsigned long)elem->tp_cb));
-                        BUG_ON(!ret);
-                        ret = tracepoint_probe_register_noupdate(
-                                elem->tp_name,
-                                elem->tp_cb);
-                } else {
-                        ret = tracepoint_probe_unregister_noupdate(
-                                elem->tp_name,
-                                elem->tp_cb);
-                        /*
-                         * tracepoint_probe_update_all() must be called
-                         * before the module containing tp_cb is unloaded.
-                         */
-                        module_put(__module_text_address(
-                                (unsigned long)elem->tp_cb));
-                }
-        }
-        elem->state = active;
-
-        return ret;
-}
-
-/*
- * Disable a marker and its probe callback.
- * Note: only waiting an RCU period after setting elem->call to the empty
- * function insures that the original callback is not used anymore. This insured
- * by rcu_read_lock_sched around the call site.
- */
-static void disable_marker(struct marker *elem)
-{
-        int ret;
-
-        /* leave "call" as is. It is known statically. */
-        if (elem->tp_name && elem->state) {
-                WARN_ON(!elem->tp_cb);
-                /*
-                 * It is ok to directly call the probe registration because type
-                 * checking has been done in the __trace_mark_tp() macro.
-                 */
-                ret = tracepoint_probe_unregister_noupdate(elem->tp_name,
-                        elem->tp_cb);
-                WARN_ON(ret);
-                /*
-                 * tracepoint_probe_update_all() must be called
-                 * before the module containing tp_cb is unloaded.
-                 */
-                module_put(__module_text_address((unsigned long)elem->tp_cb));
-        }
-        elem->state = 0;
-        elem->single.func = __mark_empty_function;
-        /* Update the function before setting the ptype */
-        smp_wmb();
-        elem->ptype = 0;        /* single probe */
-        /*
-         * Leave the private data and id there, because removal is racy and
-         * should be done only after an RCU period. These are never used until
-         * the next initialization anyway.
-         */
-}
-
-/**
- * marker_update_probe_range - Update a probe range
- * @begin: beginning of the range
- * @end: end of the range
- *
- * Updates the probe callback corresponding to a range of markers.
- */
-void marker_update_probe_range(struct marker *begin,
-        struct marker *end)
-{
-        struct marker *iter;
-        struct marker_entry *mark_entry;
-
-        mutex_lock(&markers_mutex);
-        for (iter = begin; iter < end; iter++) {
-                mark_entry = get_marker(iter->name);
-                if (mark_entry) {
-                        set_marker(mark_entry, iter, !!mark_entry->refcount);
-                        /*
-                         * ignore error, continue
-                         */
-                } else {
-                        disable_marker(iter);
-                }
-        }
-        mutex_unlock(&markers_mutex);
-}
-
-/*
- * Update probes, removing the faulty probes.
- *
- * Internal callback only changed before the first probe is connected to it.
- * Single probe private data can only be changed on 0 -> 1 and 2 -> 1
- * transitions.  All other transitions will leave the old private data valid.
- * This makes the non-atomicity of the callback/private data updates valid.
- *
- * "special case" updates :
- * 0 -> 1 callback
- * 1 -> 0 callback
- * 1 -> 2 callbacks
- * 2 -> 1 callbacks
- * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates.
- * Site effect : marker_set_format may delete the marker entry (creating a
- * replacement).
- */
-static void marker_update_probes(void)
-{
-        /* Core kernel markers */
-        marker_update_probe_range(__start___markers, __stop___markers);
-        /* Markers in modules. */
-        module_update_markers();
-        tracepoint_probe_update_all();
-}
-
-/**
- * marker_probe_register -  Connect a probe to a marker
- * @name: marker name
- * @format: format string
- * @probe: probe handler
- * @probe_private: probe private data
- *
- * private data must be a valid allocated memory address, or NULL.
- * Returns 0 if ok, error value on error.
- * The probe address must at least be aligned on the architecture pointer size.
- */
-int marker_probe_register(const char *name, const char *format,
-                        marker_probe_func *probe, void *probe_private)
-{
-        struct marker_entry *entry;
-        int ret = 0;
-        struct marker_probe_closure *old;
-
-        mutex_lock(&markers_mutex);
-        entry = get_marker(name);
-        if (!entry) {
-                entry = add_marker(name, format);
-                if (IS_ERR(entry))
-                        ret = PTR_ERR(entry);
-        } else if (format) {
-                if (!entry->format)
-                        ret = marker_set_format(entry, format);
-                else if (strcmp(entry->format, format))
-                        ret = -EPERM;
-        }
-        if (ret)
-                goto end;
-
-        /*
-         * If we detect that a call_rcu is pending for this marker,
-         * make sure it's executed now.
-         */
-        if (entry->rcu_pending)
-                rcu_barrier_sched();
-        old = marker_entry_add_probe(entry, probe, probe_private);
-        if (IS_ERR(old)) {
-                ret = PTR_ERR(old);
-                goto end;
-        }
-        mutex_unlock(&markers_mutex);
-        marker_update_probes();
-        mutex_lock(&markers_mutex);
-        entry = get_marker(name);
-        if (!entry)
-                goto end;
-        if (entry->rcu_pending)
-                rcu_barrier_sched();
-        entry->oldptr = old;
-        entry->rcu_pending = 1;
-        /* write rcu_pending before calling the RCU callback */
-        smp_wmb();
-        call_rcu_sched(&entry->rcu, free_old_closure);
-end:
-        mutex_unlock(&markers_mutex);
-        return ret;
-}
-EXPORT_SYMBOL_GPL(marker_probe_register);
-
-/**
- * marker_probe_unregister -  Disconnect a probe from a marker
- * @name: marker name
- * @probe: probe function pointer
- * @probe_private: probe private data
- *
- * Returns the private data given to marker_probe_register, or an ERR_PTR().
- * We do not need to call a synchronize_sched to make sure the probes have
- * finished running before doing a module unload, because the module unload
- * itself uses stop_machine(), which insures that every preempt disabled section
- * have finished.
- */
-int marker_probe_unregister(const char *name,
-        marker_probe_func *probe, void *probe_private)
-{
-        struct marker_entry *entry;
-        struct marker_probe_closure *old;
-        int ret = -ENOENT;
-
-        mutex_lock(&markers_mutex);
-        entry = get_marker(name);
-        if (!entry)
-                goto end;
-        if (entry->rcu_pending)
-                rcu_barrier_sched();
-        old = marker_entry_remove_probe(entry, probe, probe_private);
-        mutex_unlock(&markers_mutex);
-        marker_update_probes();
-        mutex_lock(&markers_mutex);
-        entry = get_marker(name);
-        if (!entry)
-                goto end;
-        if (entry->rcu_pending)
-                rcu_barrier_sched();
-        entry->oldptr = old;
-        entry->rcu_pending = 1;
-        /* write rcu_pending before calling the RCU callback */
-        smp_wmb();
-        call_rcu_sched(&entry->rcu, free_old_closure);
-        remove_marker(name);    /* Ignore busy error message */
-        ret = 0;
-end:
-        mutex_unlock(&markers_mutex);
-        return ret;
-}
-EXPORT_SYMBOL_GPL(marker_probe_unregister);
-
-static struct marker_entry *
-get_marker_from_private_data(marker_probe_func *probe, void *probe_private)
-{
-        struct marker_entry *entry;
-        unsigned int i;
-        struct hlist_head *head;
-        struct hlist_node *node;
-
-        for (i = 0; i < MARKER_TABLE_SIZE; i++) {
-                head = &marker_table[i];
-                hlist_for_each_entry(entry, node, head, hlist) {
-                        if (!entry->ptype) {
-                                if (entry->single.func == probe
-                                                && entry->single.probe_private
-                                                == probe_private)
-                                        return entry;
-                        } else {
-                                struct marker_probe_closure *closure;
-                                closure = entry->multi;
-                                for (i = 0; closure[i].func; i++) {
-                                        if (closure[i].func == probe &&
-                                                        closure[i].probe_private
-                                                        == probe_private)
-                                                return entry;
-                                }
-                        }
-                }
-        }
-        return NULL;
-}
-
-/**
- * marker_probe_unregister_private_data -  Disconnect a probe from a marker
- * @probe: probe function
- * @probe_private: probe private data
- *
- * Unregister a probe by providing the registered private data.
- * Only removes the first marker found in hash table.
- * Return 0 on success or error value.
- * We do not need to call a synchronize_sched to make sure the probes have
- * finished running before doing a module unload, because the module unload
- * itself uses stop_machine(), which insures that every preempt disabled section
- * have finished.
- */
-int marker_probe_unregister_private_data(marker_probe_func *probe,
-                void *probe_private)
-{
-        struct marker_entry *entry;
-        int ret = 0;
-        struct marker_probe_closure *old;
-
-        mutex_lock(&markers_mutex);
-        entry = get_marker_from_private_data(probe, probe_private);
-        if (!entry) {
-                ret = -ENOENT;
-                goto end;
-        }
-        if (entry->rcu_pending)
-                rcu_barrier_sched();
-        old = marker_entry_remove_probe(entry, NULL, probe_private);
-        mutex_unlock(&markers_mutex);
-        marker_update_probes();
-        mutex_lock(&markers_mutex);
-        entry = get_marker_from_private_data(probe, probe_private);
-        if (!entry)
-                goto end;
-        if (entry->rcu_pending)
-                rcu_barrier_sched();
-        entry->oldptr = old;
-        entry->rcu_pending = 1;
-        /* write rcu_pending before calling the RCU callback */
-        smp_wmb();
-        call_rcu_sched(&entry->rcu, free_old_closure);
-        remove_marker(entry->name);     /* Ignore busy error message */
-end:
-        mutex_unlock(&markers_mutex);
-        return ret;
-}
-EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data);
-
-/**
- * marker_get_private_data - Get a marker's probe private data
- * @name: marker name
- * @probe: probe to match
- * @num: get the nth matching probe's private data
- *
- * Returns the nth private data pointer (starting from 0) matching, or an
- * ERR_PTR.
- * Returns the private data pointer, or an ERR_PTR.
- * The private data pointer should _only_ be dereferenced if the caller is the
- * owner of the data, or its content could vanish. This is mostly used to
- * confirm that a caller is the owner of a registered probe.
- */
-void *marker_get_private_data(const char *name, marker_probe_func *probe,
-                int num)
-{
-        struct hlist_head *head;
-        struct hlist_node *node;
-        struct marker_entry *e;
-        size_t name_len = strlen(name) + 1;
-        u32 hash = jhash(name, name_len-1, 0);
-        int i;
-
-        head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-        hlist_for_each_entry(e, node, head, hlist) {
-                if (!strcmp(name, e->name)) {
-                        if (!e->ptype) {
-                                if (num == 0 && e->single.func == probe)
-                                        return e->single.probe_private;
-                        } else {
-                                struct marker_probe_closure *closure;
-                                int match = 0;
-                                closure = e->multi;
-                                for (i = 0; closure[i].func; i++) {
-                                        if (closure[i].func != probe)
-                                                continue;
-                                        if (match++ == num)
-                                                return closure[i].probe_private;
-                                }
-                        }
-                        break;
-                }
-        }
-        return ERR_PTR(-ENOENT);
-}
-EXPORT_SYMBOL_GPL(marker_get_private_data);
-
-#ifdef CONFIG_MODULES
-
-int marker_module_notify(struct notifier_block *self,
-                         unsigned long val, void *data)
-{
-        struct module *mod = data;
-
-        switch (val) {
-        case MODULE_STATE_COMING:
-                marker_update_probe_range(mod->markers,
-                        mod->markers + mod->num_markers);
-                break;
-        case MODULE_STATE_GOING:
-                marker_update_probe_range(mod->markers,
-                        mod->markers + mod->num_markers);
-                break;
-        }
-        return 0;
-}
-
-struct notifier_block marker_module_nb = {
-        .notifier_call = marker_module_notify,
-        .priority = 0,
-};
-
-static int init_markers(void)
-{
-        return register_module_notifier(&marker_module_nb);
-}
-__initcall(init_markers);
-
-#endif /* CONFIG_MODULES */
diff --git a/kernel/module.c b/kernel/module.c
index 05ce49ced8f6..8b7d8805819d 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -47,6 +47,7 @@
 #include <linux/rculist.h>
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
 #include <linux/license.h>
 #include <asm/sections.h>
 #include <linux/tracepoint.h>
@@ -1535,6 +1536,10 @@ static void free_module(struct module *mod)
 
         /* Finally, free the core (containing the module structure) */
         module_free(mod, mod->module_core);
+
+#ifdef CONFIG_MPU
+        update_protections(current->mm);
+#endif
 }
 
 void *__symbol_get(const char *symbol)
@@ -1792,6 +1797,17 @@ static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
         }
 }
 
+static void free_modinfo(struct module *mod)
+{
+        struct module_attribute *attr;
+        int i;
+
+        for (i = 0; (attr = modinfo_attrs[i]); i++) {
+                if (attr->free)
+                        attr->free(mod);
+        }
+}
+
 #ifdef CONFIG_KALLSYMS
 
 /* lookup symbol in given range of kernel_symbols */
@@ -1857,13 +1873,93 @@ static char elf_type(const Elf_Sym *sym,
         return '?';
 }
 
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+                           unsigned int shnum)
+{
+        const Elf_Shdr *sec;
+
+        if (src->st_shndx == SHN_UNDEF
+            || src->st_shndx >= shnum
+            || !src->st_name)
+                return false;
+
+        sec = sechdrs + src->st_shndx;
+        if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+            || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+            || (sec->sh_entsize & INIT_OFFSET_MASK))
+                return false;
+
+        return true;
+}
+
+static unsigned long layout_symtab(struct module *mod,
+                                   Elf_Shdr *sechdrs,
+                                   unsigned int symindex,
+                                   unsigned int strindex,
+                                   const Elf_Ehdr *hdr,
+                                   const char *secstrings,
+                                   unsigned long *pstroffs,
+                                   unsigned long *strmap)
+{
+        unsigned long symoffs;
+        Elf_Shdr *symsect = sechdrs + symindex;
+        Elf_Shdr *strsect = sechdrs + strindex;
+        const Elf_Sym *src;
+        const char *strtab;
+        unsigned int i, nsrc, ndst;
+
+        /* Put symbol section at end of init part of module. */
+        symsect->sh_flags |= SHF_ALLOC;
+        symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
+                                         symindex) | INIT_OFFSET_MASK;
+        DEBUGP("\t%s\n", secstrings + symsect->sh_name);
+
+        src = (void *)hdr + symsect->sh_offset;
+        nsrc = symsect->sh_size / sizeof(*src);
+        strtab = (void *)hdr + strsect->sh_offset;
+        for (ndst = i = 1; i < nsrc; ++i, ++src)
+                if (is_core_symbol(src, sechdrs, hdr->e_shnum)) {
+                        unsigned int j = src->st_name;
+
+                        while(!__test_and_set_bit(j, strmap) && strtab[j])
+                                ++j;
+                        ++ndst;
+                }
+
+        /* Append room for core symbols at end of core part. */
+        symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
+        mod->core_size = symoffs + ndst * sizeof(Elf_Sym);
+
+        /* Put string table section at end of init part of module. */
+        strsect->sh_flags |= SHF_ALLOC;
+        strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
+                                         strindex) | INIT_OFFSET_MASK;
+        DEBUGP("\t%s\n", secstrings + strsect->sh_name);
+
+        /* Append room for core symbols' strings at end of core part. */
+        *pstroffs = mod->core_size;
+        __set_bit(0, strmap);
+        mod->core_size += bitmap_weight(strmap, strsect->sh_size);
+
+        return symoffs;
+}
+
 static void add_kallsyms(struct module *mod,
                          Elf_Shdr *sechdrs,
+                         unsigned int shnum,
                          unsigned int symindex,
                          unsigned int strindex,
-                         const char *secstrings)
+                         unsigned long symoffs,
+                         unsigned long stroffs,
+                         const char *secstrings,
+                         unsigned long *strmap)
 {
-        unsigned int i;
+        unsigned int i, ndst;
+        const Elf_Sym *src;
+        Elf_Sym *dst;
+        char *s;
 
         mod->symtab = (void *)sechdrs[symindex].sh_addr;
         mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
@@ -1873,13 +1969,46 @@ static void add_kallsyms(struct module *mod,
         for (i = 0; i < mod->num_symtab; i++)
                 mod->symtab[i].st_info
                         = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
+
+        mod->core_symtab = dst = mod->module_core + symoffs;
+        src = mod->symtab;
+        *dst = *src;
+        for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
+                if (!is_core_symbol(src, sechdrs, shnum))
+                        continue;
+                dst[ndst] = *src;
+                dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name);
+                ++ndst;
+        }
+        mod->core_num_syms = ndst;
+
+        mod->core_strtab = s = mod->module_core + stroffs;
+        for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i)
+                if (test_bit(i, strmap))
+                        *++s = mod->strtab[i];
 }
 #else
+static inline unsigned long layout_symtab(struct module *mod,
+                                          Elf_Shdr *sechdrs,
+                                          unsigned int symindex,
+                                          unsigned int strindex,
+                                          const Elf_Ehdr *hdr,
+                                          const char *secstrings,
+                                          unsigned long *pstroffs,
+                                          unsigned long *strmap)
+{
+        return 0;
+}
+
 static inline void add_kallsyms(struct module *mod,
                                 Elf_Shdr *sechdrs,
+                                unsigned int shnum,
                                 unsigned int symindex,
                                 unsigned int strindex,
-                                const char *secstrings)
+                                unsigned long symoffs,
+                                unsigned long stroffs,
+                                const char *secstrings,
+                                const unsigned long *strmap)
 {
 }
 #endif /* CONFIG_KALLSYMS */
@@ -1954,6 +2083,8 @@ static noinline struct module *load_module(void __user *umod,
         struct module *mod;
         long err = 0;
         void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
+        unsigned long symoffs, stroffs, *strmap;
+
         mm_segment_t old_fs;
 
         DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
@@ -2035,11 +2166,6 @@ static noinline struct module *load_module(void __user *umod,
         /* Don't keep modinfo and version sections. */
         sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
         sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
-#ifdef CONFIG_KALLSYMS
-        /* Keep symbol and string tables for decoding later. */
-        sechdrs[symindex].sh_flags |= SHF_ALLOC;
-        sechdrs[strindex].sh_flags |= SHF_ALLOC;
-#endif
 
         /* Check module struct version now, before we try to use module. */
         if (!check_modstruct_version(sechdrs, versindex, mod)) {
@@ -2075,6 +2201,13 @@ static noinline struct module *load_module(void __user *umod,
                 goto free_hdr;
         }
 
+        strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
+                         * sizeof(long), GFP_KERNEL);
+        if (!strmap) {
+                err = -ENOMEM;
+                goto free_mod;
+        }
+
         if (find_module(mod->name)) {
                 err = -EEXIST;
                 goto free_mod;
@@ -2104,6 +2237,8 @@ static noinline struct module *load_module(void __user *umod,
            this is done generically; there doesn't appear to be any
            special cases for the architectures. */
         layout_sections(mod, hdr, sechdrs, secstrings);
+        symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
+                                secstrings, &stroffs, strmap);
 
         /* Do the allocs. */
         ptr = module_alloc_update_bounds(mod->core_size);
@@ -2237,10 +2372,6 @@ static noinline struct module *load_module(void __user *umod,
                                   sizeof(*mod->ctors), &mod->num_ctors);
 #endif
 
-#ifdef CONFIG_MARKERS
-        mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers",
-                                    sizeof(*mod->markers), &mod->num_markers);
-#endif
 #ifdef CONFIG_TRACEPOINTS
         mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
                                         "__tracepoints",
@@ -2312,7 +2443,10 @@ static noinline struct module *load_module(void __user *umod,
         percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
                        sechdrs[pcpuindex].sh_size);
 
-        add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
+        add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
+                     symoffs, stroffs, secstrings, strmap);
+        kfree(strmap);
+        strmap = NULL;
 
         if (!mod->taints) {
                 struct _ddebug *debug;
@@ -2384,13 +2518,14 @@ static noinline struct module *load_module(void __user *umod,
         synchronize_sched();
         module_arch_cleanup(mod);
  cleanup:
+        free_modinfo(mod);
         kobject_del(&mod->mkobj.kobj);
         kobject_put(&mod->mkobj.kobj);
  free_unload:
         module_unload_free(mod);
 #if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
- free_init:
         percpu_modfree(mod->refptr);
+ free_init:
 #endif
         module_free(mod, mod->module_init);
  free_core:
@@ -2401,6 +2536,7 @@ static noinline struct module *load_module(void __user *umod,
                 percpu_modfree(percpu);
  free_mod:
         kfree(args);
+        kfree(strmap);
  free_hdr:
         vfree(hdr);
         return ERR_PTR(err);
@@ -2490,6 +2626,11 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
         /* Drop initial reference. */
         module_put(mod);
         trim_init_extable(mod);
+#ifdef CONFIG_KALLSYMS
+        mod->num_symtab = mod->core_num_syms;
+        mod->symtab = mod->core_symtab;
+        mod->strtab = mod->core_strtab;
+#endif
         module_free(mod, mod->module_init);
         mod->module_init = NULL;
         mod->init_size = 0;
@@ -2951,27 +3092,12 @@ void module_layout(struct module *mod,
                    struct modversion_info *ver,
                    struct kernel_param *kp,
                    struct kernel_symbol *ks,
-                   struct marker *marker,
                    struct tracepoint *tp)
 {
 }
 EXPORT_SYMBOL(module_layout);
 #endif
 
-#ifdef CONFIG_MARKERS
-void module_update_markers(void)
-{
-        struct module *mod;
-
-        mutex_lock(&module_mutex);
-        list_for_each_entry(mod, &modules, list)
-                if (!mod->taints)
-                        marker_update_probe_range(mod->markers,
-                                mod->markers + mod->num_markers);
-        mutex_unlock(&module_mutex);
-}
-#endif
-
 #ifdef CONFIG_TRACEPOINTS
 void module_update_tracepoints(void)
 {
diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 50d022e5a560..ec815a960b5d 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -16,6 +16,7 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/poison.h>
+#include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
 #include <linux/interrupt.h>
diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c
index 5aa854f9e5ae..2a5dfec8efe0 100644
--- a/kernel/ns_cgroup.c
+++ b/kernel/ns_cgroup.c
@@ -42,8 +42,8 @@ int ns_cgroup_clone(struct task_struct *task, struct pid *pid)
  *       (hence either you are in the same cgroup as task, or in an
  *        ancestor cgroup thereof)
  */
-static int ns_can_attach(struct cgroup_subsys *ss,
-                struct cgroup *new_cgroup, struct task_struct *task)
+static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup,
+                         struct task_struct *task, bool threadgroup)
 {
         if (current != task) {
                 if (!capable(CAP_SYS_ADMIN))
@@ -56,6 +56,18 @@ static int ns_can_attach(struct cgroup_subsys *ss,
         if (!cgroup_is_descendant(new_cgroup, task))
                 return -EPERM;
 
+        if (threadgroup) {
+                struct task_struct *c;
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
+                        if (!cgroup_is_descendant(new_cgroup, c)) {
+                                rcu_read_unlock();
+                                return -EPERM;
+                        }
+                }
+                rcu_read_unlock();
+        }
+
         return 0;
 }
 
diff --git a/kernel/panic.c b/kernel/panic.c
index 512ab73b0ca3..96b45d0b4ba5 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -90,6 +90,8 @@ NORET_TYPE void panic(const char * fmt, ...)
 
         atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
 
+        bust_spinlocks(0);
+
         if (!panic_blink)
                 panic_blink = no_blink;
 
@@ -136,7 +138,6 @@ NORET_TYPE void panic(const char * fmt, ...)
                 mdelay(1);
                 i++;
         }
-        bust_spinlocks(0);
 }
 
 EXPORT_SYMBOL(panic);
@@ -177,7 +178,7 @@ static const struct tnt tnts[] = {
  *  'W' - Taint on warning.
  *  'C' - modules from drivers/staging are loaded.
  *
- *      The string is overwritten by the next call to print_taint().
+ *      The string is overwritten by the next call to print_tainted().
  */
 const char *print_tainted(void)
 {
diff --git a/kernel/params.c b/kernel/params.c
index 7f6912ced2ba..9da58eabdcb2 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -23,6 +23,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/ctype.h>
 
 #if 0
 #define DEBUGP printk
@@ -87,7 +88,7 @@ static char *next_arg(char *args, char **param, char **val)
         }
 
         for (i = 0; args[i]; i++) {
-                if (args[i] == ' ' && !in_quote)
+                if (isspace(args[i]) && !in_quote)
                         break;
                 if (equals == 0) {
                         if (args[i] == '=')
@@ -121,7 +122,7 @@ static char *next_arg(char *args, char **param, char **val)
                 next = args + i;
 
         /* Chew up trailing spaces. */
-        while (*next == ' ')
+        while (isspace(*next))
                 next++;
         return next;
 }
@@ -138,7 +139,7 @@ int parse_args(const char *name,
         DEBUGP("Parsing ARGS: %s\n", args);
 
         /* Chew leading spaces */
-        while (*args == ' ')
+        while (isspace(*args))
                 args++;
 
         while (*args) {
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
deleted file mode 100644
index 8cb94a52d1bb..000000000000
--- a/kernel/perf_counter.c
+++ /dev/null
@@ -1,4963 +0,0 @@
-/*
- * Performance counter core code
- *
- *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
- *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
- *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
- *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
- *
- *  For licensing details see kernel-base/COPYING
- */
-
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/cpu.h>
-#include <linux/smp.h>
-#include <linux/file.h>
-#include <linux/poll.h>
-#include <linux/sysfs.h>
-#include <linux/dcache.h>
-#include <linux/percpu.h>
-#include <linux/ptrace.h>
-#include <linux/vmstat.h>
-#include <linux/hardirq.h>
-#include <linux/rculist.h>
-#include <linux/uaccess.h>
-#include <linux/syscalls.h>
-#include <linux/anon_inodes.h>
-#include <linux/kernel_stat.h>
-#include <linux/perf_counter.h>
-
-#include <asm/irq_regs.h>
-
-/*
- * Each CPU has a list of per CPU counters:
- */
-DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
-
-int perf_max_counters __read_mostly = 1;
-static int perf_reserved_percpu __read_mostly;
-static int perf_overcommit __read_mostly = 1;
-
-static atomic_t nr_counters __read_mostly;
-static atomic_t nr_mmap_counters __read_mostly;
-static atomic_t nr_comm_counters __read_mostly;
-static atomic_t nr_task_counters __read_mostly;
-
-/*
- * perf counter paranoia level:
- *  -1 - not paranoid at all
- *   0 - disallow raw tracepoint access for unpriv
- *   1 - disallow cpu counters for unpriv
- *   2 - disallow kernel profiling for unpriv
- */
-int sysctl_perf_counter_paranoid __read_mostly = 1;
-
-static inline bool perf_paranoid_tracepoint_raw(void)
-{
-        return sysctl_perf_counter_paranoid > -1;
-}
-
-static inline bool perf_paranoid_cpu(void)
-{
-        return sysctl_perf_counter_paranoid > 0;
-}
-
-static inline bool perf_paranoid_kernel(void)
-{
-        return sysctl_perf_counter_paranoid > 1;
-}
-
-int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */
-
-/*
- * max perf counter sample rate
- */
-int sysctl_perf_counter_sample_rate __read_mostly = 100000;
-
-static atomic64_t perf_counter_id;
-
-/*
- * Lock for (sysadmin-configurable) counter reservations:
- */
-static DEFINE_SPINLOCK(perf_resource_lock);
-
-/*
- * Architecture provided APIs - weak aliases:
- */
-extern __weak const struct pmu *hw_perf_counter_init(struct perf_counter *counter)
-{
-        return NULL;
-}
-
-void __weak hw_perf_disable(void)               { barrier(); }
-void __weak hw_perf_enable(void)                { barrier(); }
-
-void __weak hw_perf_counter_setup(int cpu)      { barrier(); }
-void __weak hw_perf_counter_setup_online(int cpu)       { barrier(); }
-
-int __weak
-hw_perf_group_sched_in(struct perf_counter *group_leader,
-               struct perf_cpu_context *cpuctx,
-               struct perf_counter_context *ctx, int cpu)
-{
-        return 0;
-}
-
-void __weak perf_counter_print_debug(void)      { }
-
-static DEFINE_PER_CPU(int, perf_disable_count);
-
-void __perf_disable(void)
-{
-        __get_cpu_var(perf_disable_count)++;
-}
-
-bool __perf_enable(void)
-{
-        return !--__get_cpu_var(perf_disable_count);
-}
-
-void perf_disable(void)
-{
-        __perf_disable();
-        hw_perf_disable();
-}
-
-void perf_enable(void)
-{
-        if (__perf_enable())
-                hw_perf_enable();
-}
-
-static void get_ctx(struct perf_counter_context *ctx)
-{
-        WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
-}
-
-static void free_ctx(struct rcu_head *head)
-{
-        struct perf_counter_context *ctx;
-
-        ctx = container_of(head, struct perf_counter_context, rcu_head);
-        kfree(ctx);
-}
-
-static void put_ctx(struct perf_counter_context *ctx)
-{
-        if (atomic_dec_and_test(&ctx->refcount)) {
-                if (ctx->parent_ctx)
-                        put_ctx(ctx->parent_ctx);
-                if (ctx->task)
-                        put_task_struct(ctx->task);
-                call_rcu(&ctx->rcu_head, free_ctx);
-        }
-}
-
-static void unclone_ctx(struct perf_counter_context *ctx)
-{
-        if (ctx->parent_ctx) {
-                put_ctx(ctx->parent_ctx);
-                ctx->parent_ctx = NULL;
-        }
-}
-
-/*
- * If we inherit counters we want to return the parent counter id
- * to userspace.
- */
-static u64 primary_counter_id(struct perf_counter *counter)
-{
-        u64 id = counter->id;
-
-        if (counter->parent)
-                id = counter->parent->id;
-
-        return id;
-}
-
-/*
- * Get the perf_counter_context for a task and lock it.
- * This has to cope with with the fact that until it is locked,
- * the context could get moved to another task.
- */
-static struct perf_counter_context *
-perf_lock_task_context(struct task_struct *task, unsigned long *flags)
-{
-        struct perf_counter_context *ctx;
-
-        rcu_read_lock();
- retry:
-        ctx = rcu_dereference(task->perf_counter_ctxp);
-        if (ctx) {
-                /*
-                 * If this context is a clone of another, it might
-                 * get swapped for another underneath us by
-                 * perf_counter_task_sched_out, though the
-                 * rcu_read_lock() protects us from any context
-                 * getting freed.  Lock the context and check if it
-                 * got swapped before we could get the lock, and retry
-                 * if so.  If we locked the right context, then it
-                 * can't get swapped on us any more.
-                 */
-                spin_lock_irqsave(&ctx->lock, *flags);
-                if (ctx != rcu_dereference(task->perf_counter_ctxp)) {
-                        spin_unlock_irqrestore(&ctx->lock, *flags);
-                        goto retry;
-                }
-
-                if (!atomic_inc_not_zero(&ctx->refcount)) {
-                        spin_unlock_irqrestore(&ctx->lock, *flags);
-                        ctx = NULL;
-                }
-        }
-        rcu_read_unlock();
-        return ctx;
-}
-
-/*
- * Get the context for a task and increment its pin_count so it
- * can't get swapped to another task.  This also increments its
- * reference count so that the context can't get freed.
- */
-static struct perf_counter_context *perf_pin_task_context(struct task_struct *task)
-{
-        struct perf_counter_context *ctx;
-        unsigned long flags;
-
-        ctx = perf_lock_task_context(task, &flags);
-        if (ctx) {
-                ++ctx->pin_count;
-                spin_unlock_irqrestore(&ctx->lock, flags);
-        }
-        return ctx;
-}
-
-static void perf_unpin_context(struct perf_counter_context *ctx)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&ctx->lock, flags);
-        --ctx->pin_count;
-        spin_unlock_irqrestore(&ctx->lock, flags);
-        put_ctx(ctx);
-}
-
-/*
- * Add a counter from the lists for its context.
- * Must be called with ctx->mutex and ctx->lock held.
- */
-static void
-list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
-{
-        struct perf_counter *group_leader = counter->group_leader;
-
-        /*
-         * Depending on whether it is a standalone or sibling counter,
-         * add it straight to the context's counter list, or to the group
-         * leader's sibling list:
-         */
-        if (group_leader == counter)
-                list_add_tail(&counter->list_entry, &ctx->counter_list);
-        else {
-                list_add_tail(&counter->list_entry, &group_leader->sibling_list);
-                group_leader->nr_siblings++;
-        }
-
-        list_add_rcu(&counter->event_entry, &ctx->event_list);
-        ctx->nr_counters++;
-        if (counter->attr.inherit_stat)
-                ctx->nr_stat++;
-}
-
-/*
- * Remove a counter from the lists for its context.
- * Must be called with ctx->mutex and ctx->lock held.
- */
-static void
-list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
-{
-        struct perf_counter *sibling, *tmp;
-
-        if (list_empty(&counter->list_entry))
-                return;
-        ctx->nr_counters--;
-        if (counter->attr.inherit_stat)
-                ctx->nr_stat--;
-
-        list_del_init(&counter->list_entry);
-        list_del_rcu(&counter->event_entry);
-
-        if (counter->group_leader != counter)
-                counter->group_leader->nr_siblings--;
-
-        /*
-         * If this was a group counter with sibling counters then
-         * upgrade the siblings to singleton counters by adding them
-         * to the context list directly:
-         */
-        list_for_each_entry_safe(sibling, tmp,
-                                 &counter->sibling_list, list_entry) {
-
-                list_move_tail(&sibling->list_entry, &ctx->counter_list);
-                sibling->group_leader = sibling;
-        }
-}
-
-static void
-counter_sched_out(struct perf_counter *counter,
-                  struct perf_cpu_context *cpuctx,
-                  struct perf_counter_context *ctx)
-{
-        if (counter->state != PERF_COUNTER_STATE_ACTIVE)
-                return;
-
-        counter->state = PERF_COUNTER_STATE_INACTIVE;
-        if (counter->pending_disable) {
-                counter->pending_disable = 0;
-                counter->state = PERF_COUNTER_STATE_OFF;
-        }
-        counter->tstamp_stopped = ctx->time;
-        counter->pmu->disable(counter);
-        counter->oncpu = -1;
-
-        if (!is_software_counter(counter))
-                cpuctx->active_oncpu--;
-        ctx->nr_active--;
-        if (counter->attr.exclusive || !cpuctx->active_oncpu)
-                cpuctx->exclusive = 0;
-}
-
-static void
-group_sched_out(struct perf_counter *group_counter,
-                struct perf_cpu_context *cpuctx,
-                struct perf_counter_context *ctx)
-{
-        struct perf_counter *counter;
-
-        if (group_counter->state != PERF_COUNTER_STATE_ACTIVE)
-                return;
-
-        counter_sched_out(group_counter, cpuctx, ctx);
-
-        /*
-         * Schedule out siblings (if any):
-         */
-        list_for_each_entry(counter, &group_counter->sibling_list, list_entry)
-                counter_sched_out(counter, cpuctx, ctx);
-
-        if (group_counter->attr.exclusive)
-                cpuctx->exclusive = 0;
-}
-
-/*
- * Cross CPU call to remove a performance counter
- *
- * We disable the counter on the hardware level first. After that we
- * remove it from the context list.
- */
-static void __perf_counter_remove_from_context(void *info)
-{
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-        struct perf_counter *counter = info;
-        struct perf_counter_context *ctx = counter->ctx;
-
-        /*
-         * If this is a task context, we need to check whether it is
-         * the current task context of this cpu. If not it has been
-         * scheduled out before the smp call arrived.
-         */
-        if (ctx->task && cpuctx->task_ctx != ctx)
-                return;
-
-        spin_lock(&ctx->lock);
-        /*
-         * Protect the list operation against NMI by disabling the
-         * counters on a global level.
-         */
-        perf_disable();
-
-        counter_sched_out(counter, cpuctx, ctx);
-
-        list_del_counter(counter, ctx);
-
-        if (!ctx->task) {
-                /*
-                 * Allow more per task counters with respect to the
-                 * reservation:
-                 */
-                cpuctx->max_pertask =
-                        min(perf_max_counters - ctx->nr_counters,
-                            perf_max_counters - perf_reserved_percpu);
-        }
-
-        perf_enable();
-        spin_unlock(&ctx->lock);
-}
-
-
-/*
- * Remove the counter from a task's (or a CPU's) list of counters.
- *
- * Must be called with ctx->mutex held.
- *
- * CPU counters are removed with a smp call. For task counters we only
- * call when the task is on a CPU.
- *
- * If counter->ctx is a cloned context, callers must make sure that
- * every task struct that counter->ctx->task could possibly point to
- * remains valid.  This is OK when called from perf_release since
- * that only calls us on the top-level context, which can't be a clone.
- * When called from perf_counter_exit_task, it's OK because the
- * context has been detached from its task.
- */
-static void perf_counter_remove_from_context(struct perf_counter *counter)
-{
-        struct perf_counter_context *ctx = counter->ctx;
-        struct task_struct *task = ctx->task;
-
-        if (!task) {
-                /*
-                 * Per cpu counters are removed via an smp call and
-                 * the removal is always sucessful.
-                 */
-                smp_call_function_single(counter->cpu,
-                                         __perf_counter_remove_from_context,
-                                         counter, 1);
-                return;
-        }
-
-retry:
-        task_oncpu_function_call(task, __perf_counter_remove_from_context,
-                                 counter);
-
-        spin_lock_irq(&ctx->lock);
-        /*
-         * If the context is active we need to retry the smp call.
-         */
-        if (ctx->nr_active && !list_empty(&counter->list_entry)) {
-                spin_unlock_irq(&ctx->lock);
-                goto retry;
-        }
-
-        /*
-         * The lock prevents that this context is scheduled in so we
-         * can remove the counter safely, if the call above did not
-         * succeed.
-         */
-        if (!list_empty(&counter->list_entry)) {
-                list_del_counter(counter, ctx);
-        }
-        spin_unlock_irq(&ctx->lock);
-}
-
-static inline u64 perf_clock(void)
-{
-        return cpu_clock(smp_processor_id());
-}
-
-/*
- * Update the record of the current time in a context.
- */
-static void update_context_time(struct perf_counter_context *ctx)
-{
-        u64 now = perf_clock();
-
-        ctx->time += now - ctx->timestamp;
-        ctx->timestamp = now;
-}
-
-/*
- * Update the total_time_enabled and total_time_running fields for a counter.
- */
-static void update_counter_times(struct perf_counter *counter)
-{
-        struct perf_counter_context *ctx = counter->ctx;
-        u64 run_end;
-
-        if (counter->state < PERF_COUNTER_STATE_INACTIVE ||
-            counter->group_leader->state < PERF_COUNTER_STATE_INACTIVE)
-                return;
-
-        counter->total_time_enabled = ctx->time - counter->tstamp_enabled;
-
-        if (counter->state == PERF_COUNTER_STATE_INACTIVE)
-                run_end = counter->tstamp_stopped;
-        else
-                run_end = ctx->time;
-
-        counter->total_time_running = run_end - counter->tstamp_running;
-}
-
-/*
- * Update total_time_enabled and total_time_running for all counters in a group.
- */
-static void update_group_times(struct perf_counter *leader)
-{
-        struct perf_counter *counter;
-
-        update_counter_times(leader);
-        list_for_each_entry(counter, &leader->sibling_list, list_entry)
-                update_counter_times(counter);
-}
-
-/*
- * Cross CPU call to disable a performance counter
- */
-static void __perf_counter_disable(void *info)
-{
-        struct perf_counter *counter = info;
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-        struct perf_counter_context *ctx = counter->ctx;
-
-        /*
-         * If this is a per-task counter, need to check whether this
-         * counter's task is the current task on this cpu.
-         */
-        if (ctx->task && cpuctx->task_ctx != ctx)
-                return;
-
-        spin_lock(&ctx->lock);
-
-        /*
-         * If the counter is on, turn it off.
-         * If it is in error state, leave it in error state.
-         */
-        if (counter->state >= PERF_COUNTER_STATE_INACTIVE) {
-                update_context_time(ctx);
-                update_group_times(counter);
-                if (counter == counter->group_leader)
-                        group_sched_out(counter, cpuctx, ctx);
-                else
-                        counter_sched_out(counter, cpuctx, ctx);
-                counter->state = PERF_COUNTER_STATE_OFF;
-        }
-
-        spin_unlock(&ctx->lock);
-}
-
-/*
- * Disable a counter.
- *
- * If counter->ctx is a cloned context, callers must make sure that
- * every task struct that counter->ctx->task could possibly point to
- * remains valid.  This condition is satisifed when called through
- * perf_counter_for_each_child or perf_counter_for_each because they
- * hold the top-level counter's child_mutex, so any descendant that
- * goes to exit will block in sync_child_counter.
- * When called from perf_pending_counter it's OK because counter->ctx
- * is the current context on this CPU and preemption is disabled,
- * hence we can't get into perf_counter_task_sched_out for this context.
- */
-static void perf_counter_disable(struct perf_counter *counter)
-{
-        struct perf_counter_context *ctx = counter->ctx;
-        struct task_struct *task = ctx->task;
-
-        if (!task) {
-                /*
-                 * Disable the counter on the cpu that it's on
-                 */
-                smp_call_function_single(counter->cpu, __perf_counter_disable,
-                                         counter, 1);
-                return;
-        }
-
- retry:
-        task_oncpu_function_call(task, __perf_counter_disable, counter);
-
-        spin_lock_irq(&ctx->lock);
-        /*
-         * If the counter is still active, we need to retry the cross-call.
-         */
-        if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
-                spin_unlock_irq(&ctx->lock);
-                goto retry;
-        }
-
-        /*
-         * Since we have the lock this context can't be scheduled
-         * in, so we can change the state safely.
-         */
-        if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
-                update_group_times(counter);
-                counter->state = PERF_COUNTER_STATE_OFF;
-        }
-
-        spin_unlock_irq(&ctx->lock);
-}
-
-static int
-counter_sched_in(struct perf_counter *counter,
-                 struct perf_cpu_context *cpuctx,
-                 struct perf_counter_context *ctx,
-                 int cpu)
-{
-        if (counter->state <= PERF_COUNTER_STATE_OFF)
-                return 0;
-
-        counter->state = PERF_COUNTER_STATE_ACTIVE;
-        counter->oncpu = cpu;   /* TODO: put 'cpu' into cpuctx->cpu */
-        /*
-         * The new state must be visible before we turn it on in the hardware:
-         */
-        smp_wmb();
-
-        if (counter->pmu->enable(counter)) {
-                counter->state = PERF_COUNTER_STATE_INACTIVE;
-                counter->oncpu = -1;
-                return -EAGAIN;
-        }
-
-        counter->tstamp_running += ctx->time - counter->tstamp_stopped;
-
-        if (!is_software_counter(counter))
-                cpuctx->active_oncpu++;
-        ctx->nr_active++;
-
-        if (counter->attr.exclusive)
-                cpuctx->exclusive = 1;
-
-        return 0;
-}
-
-static int
-group_sched_in(struct perf_counter *group_counter,
-               struct perf_cpu_context *cpuctx,
-               struct perf_counter_context *ctx,
-               int cpu)
-{
-        struct perf_counter *counter, *partial_group;
-        int ret;
-
-        if (group_counter->state == PERF_COUNTER_STATE_OFF)
-                return 0;
-
-        ret = hw_perf_group_sched_in(group_counter, cpuctx, ctx, cpu);
-        if (ret)
-                return ret < 0 ? ret : 0;
-
-        if (counter_sched_in(group_counter, cpuctx, ctx, cpu))
-                return -EAGAIN;
-
-        /*
-         * Schedule in siblings as one group (if any):
-         */
-        list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
-                if (counter_sched_in(counter, cpuctx, ctx, cpu)) {
-                        partial_group = counter;
-                        goto group_error;
-                }
-        }
-
-        return 0;
-
-group_error:
-        /*
-         * Groups can be scheduled in as one unit only, so undo any
-         * partial group before returning:
-         */
-        list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
-                if (counter == partial_group)
-                        break;
-                counter_sched_out(counter, cpuctx, ctx);
-        }
-        counter_sched_out(group_counter, cpuctx, ctx);
-
-        return -EAGAIN;
-}
-
-/*
- * Return 1 for a group consisting entirely of software counters,
- * 0 if the group contains any hardware counters.
- */
-static int is_software_only_group(struct perf_counter *leader)
-{
-        struct perf_counter *counter;
-
-        if (!is_software_counter(leader))
-                return 0;
-
-        list_for_each_entry(counter, &leader->sibling_list, list_entry)
-                if (!is_software_counter(counter))
-                        return 0;
-
-        return 1;
-}
-
-/*
- * Work out whether we can put this counter group on the CPU now.
- */
-static int group_can_go_on(struct perf_counter *counter,
-                           struct perf_cpu_context *cpuctx,
-                           int can_add_hw)
-{
-        /*
-         * Groups consisting entirely of software counters can always go on.
-         */
-        if (is_software_only_group(counter))
-                return 1;
-        /*
-         * If an exclusive group is already on, no other hardware
-         * counters can go on.
-         */
-        if (cpuctx->exclusive)
-                return 0;
-        /*
-         * If this group is exclusive and there are already
-         * counters on the CPU, it can't go on.
-         */
-        if (counter->attr.exclusive && cpuctx->active_oncpu)
-                return 0;
-        /*
-         * Otherwise, try to add it if all previous groups were able
-         * to go on.
-         */
-        return can_add_hw;
-}
-
-static void add_counter_to_ctx(struct perf_counter *counter,
-                               struct perf_counter_context *ctx)
-{
-        list_add_counter(counter, ctx);
-        counter->tstamp_enabled = ctx->time;
-        counter->tstamp_running = ctx->time;
-        counter->tstamp_stopped = ctx->time;
-}
-
-/*
- * Cross CPU call to install and enable a performance counter
- *
- * Must be called with ctx->mutex held
- */
-static void __perf_install_in_context(void *info)
-{
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-        struct perf_counter *counter = info;
-        struct perf_counter_context *ctx = counter->ctx;
-        struct perf_counter *leader = counter->group_leader;
-        int cpu = smp_processor_id();
-        int err;
-
-        /*
-         * If this is a task context, we need to check whether it is
-         * the current task context of this cpu. If not it has been
-         * scheduled out before the smp call arrived.
-         * Or possibly this is the right context but it isn't
-         * on this cpu because it had no counters.
-         */
-        if (ctx->task && cpuctx->task_ctx != ctx) {
-                if (cpuctx->task_ctx || ctx->task != current)
-                        return;
-                cpuctx->task_ctx = ctx;
-        }
-
-        spin_lock(&ctx->lock);
-        ctx->is_active = 1;
-        update_context_time(ctx);
-
-        /*
-         * Protect the list operation against NMI by disabling the
-         * counters on a global level. NOP for non NMI based counters.
-         */
-        perf_disable();
-
-        add_counter_to_ctx(counter, ctx);
-
-        /*
-         * Don't put the counter on if it is disabled or if
-         * it is in a group and the group isn't on.
-         */
-        if (counter->state != PERF_COUNTER_STATE_INACTIVE ||
-            (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE))
-                goto unlock;
-
-        /*
-         * An exclusive counter can't go on if there are already active
-         * hardware counters, and no hardware counter can go on if there
-         * is already an exclusive counter on.
-         */
-        if (!group_can_go_on(counter, cpuctx, 1))
-                err = -EEXIST;
-        else
-                err = counter_sched_in(counter, cpuctx, ctx, cpu);
-
-        if (err) {
-                /*
-                 * This counter couldn't go on.  If it is in a group
-                 * then we have to pull the whole group off.
-                 * If the counter group is pinned then put it in error state.
-                 */
-                if (leader != counter)
-                        group_sched_out(leader, cpuctx, ctx);
-                if (leader->attr.pinned) {
-                        update_group_times(leader);
-                        leader->state = PERF_COUNTER_STATE_ERROR;
-                }
-        }
-
-        if (!err && !ctx->task && cpuctx->max_pertask)
-                cpuctx->max_pertask--;
-
- unlock:
-        perf_enable();
-
-        spin_unlock(&ctx->lock);
-}
-
-/*
- * Attach a performance counter to a context
- *
- * First we add the counter to the list with the hardware enable bit
- * in counter->hw_config cleared.
- *
- * If the counter is attached to a task which is on a CPU we use a smp
- * call to enable it in the task context. The task might have been
- * scheduled away, but we check this in the smp call again.
- *
- * Must be called with ctx->mutex held.
- */
-static void
-perf_install_in_context(struct perf_counter_context *ctx,
-                        struct perf_counter *counter,
-                        int cpu)
-{
-        struct task_struct *task = ctx->task;
-
-        if (!task) {
-                /*
-                 * Per cpu counters are installed via an smp call and
-                 * the install is always sucessful.
-                 */
-                smp_call_function_single(cpu, __perf_install_in_context,
-                                         counter, 1);
-                return;
-        }
-
-retry:
-        task_oncpu_function_call(task, __perf_install_in_context,
-                                 counter);
-
-        spin_lock_irq(&ctx->lock);
-        /*
-         * we need to retry the smp call.
-         */
-        if (ctx->is_active && list_empty(&counter->list_entry)) {
-                spin_unlock_irq(&ctx->lock);
-                goto retry;
-        }
-
-        /*
-         * The lock prevents that this context is scheduled in so we
-         * can add the counter safely, if it the call above did not
-         * succeed.
-         */
-        if (list_empty(&counter->list_entry))
-                add_counter_to_ctx(counter, ctx);
-        spin_unlock_irq(&ctx->lock);
-}
-
-/*
- * Put a counter into inactive state and update time fields.
- * Enabling the leader of a group effectively enables all
- * the group members that aren't explicitly disabled, so we
- * have to update their ->tstamp_enabled also.
- * Note: this works for group members as well as group leaders
- * since the non-leader members' sibling_lists will be empty.
- */
-static void __perf_counter_mark_enabled(struct perf_counter *counter,
-                                        struct perf_counter_context *ctx)
-{
-        struct perf_counter *sub;
-
-        counter->state = PERF_COUNTER_STATE_INACTIVE;
-        counter->tstamp_enabled = ctx->time - counter->total_time_enabled;
-        list_for_each_entry(sub, &counter->sibling_list, list_entry)
-                if (sub->state >= PERF_COUNTER_STATE_INACTIVE)
-                        sub->tstamp_enabled =
-                                ctx->time - sub->total_time_enabled;
-}
-
-/*
- * Cross CPU call to enable a performance counter
- */
-static void __perf_counter_enable(void *info)
-{
-        struct perf_counter *counter = info;
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-        struct perf_counter_context *ctx = counter->ctx;
-        struct perf_counter *leader = counter->group_leader;
-        int err;
-
-        /*
-         * If this is a per-task counter, need to check whether this
-         * counter's task is the current task on this cpu.
-         */
-        if (ctx->task && cpuctx->task_ctx != ctx) {
-                if (cpuctx->task_ctx || ctx->task != current)
-                        return;
-                cpuctx->task_ctx = ctx;
-        }
-
-        spin_lock(&ctx->lock);
-        ctx->is_active = 1;
-        update_context_time(ctx);
-
-        if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
-                goto unlock;
-        __perf_counter_mark_enabled(counter, ctx);
-
-        /*
-         * If the counter is in a group and isn't the group leader,
-         * then don't put it on unless the group is on.
-         */
-        if (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE)
-                goto unlock;
-
-        if (!group_can_go_on(counter, cpuctx, 1)) {
-                err = -EEXIST;
-        } else {
-                perf_disable();
-                if (counter == leader)
-                        err = group_sched_in(counter, cpuctx, ctx,
-                                             smp_processor_id());
-                else
-                        err = counter_sched_in(counter, cpuctx, ctx,
-                                               smp_processor_id());
-                perf_enable();
-        }
-
-        if (err) {
-                /*
-                 * If this counter can't go on and it's part of a
-                 * group, then the whole group has to come off.
-                 */
-                if (leader != counter)
-                        group_sched_out(leader, cpuctx, ctx);
-                if (leader->attr.pinned) {
-                        update_group_times(leader);
-                        leader->state = PERF_COUNTER_STATE_ERROR;
-                }
-        }
-
- unlock:
-        spin_unlock(&ctx->lock);
-}
-
-/*
- * Enable a counter.
- *
- * If counter->ctx is a cloned context, callers must make sure that
- * every task struct that counter->ctx->task could possibly point to
- * remains valid.  This condition is satisfied when called through
- * perf_counter_for_each_child or perf_counter_for_each as described
- * for perf_counter_disable.
- */
-static void perf_counter_enable(struct perf_counter *counter)
-{
-        struct perf_counter_context *ctx = counter->ctx;
-        struct task_struct *task = ctx->task;
-
-        if (!task) {
-                /*
-                 * Enable the counter on the cpu that it's on
-                 */
-                smp_call_function_single(counter->cpu, __perf_counter_enable,
-                                         counter, 1);
-                return;
-        }
-
-        spin_lock_irq(&ctx->lock);
-        if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
-                goto out;
-
-        /*
-         * If the counter is in error state, clear that first.
-         * That way, if we see the counter in error state below, we
-         * know that it has gone back into error state, as distinct
-         * from the task having been scheduled away before the
-         * cross-call arrived.
-         */
-        if (counter->state == PERF_COUNTER_STATE_ERROR)
-                counter->state = PERF_COUNTER_STATE_OFF;
-
- retry:
-        spin_unlock_irq(&ctx->lock);
-        task_oncpu_function_call(task, __perf_counter_enable, counter);
-
-        spin_lock_irq(&ctx->lock);
-
-        /*
-         * If the context is active and the counter is still off,
-         * we need to retry the cross-call.
-         */
-        if (ctx->is_active && counter->state == PERF_COUNTER_STATE_OFF)
-                goto retry;
-
-        /*
-         * Since we have the lock this context can't be scheduled
-         * in, so we can change the state safely.
-         */
-        if (counter->state == PERF_COUNTER_STATE_OFF)
-                __perf_counter_mark_enabled(counter, ctx);
-
- out:
-        spin_unlock_irq(&ctx->lock);
-}
-
-static int perf_counter_refresh(struct perf_counter *counter, int refresh)
-{
-        /*
-         * not supported on inherited counters
-         */
-        if (counter->attr.inherit)
-                return -EINVAL;
-
-        atomic_add(refresh, &counter->event_limit);
-        perf_counter_enable(counter);
-
-        return 0;
-}
-
-void __perf_counter_sched_out(struct perf_counter_context *ctx,
-                              struct perf_cpu_context *cpuctx)
-{
-        struct perf_counter *counter;
-
-        spin_lock(&ctx->lock);
-        ctx->is_active = 0;
-        if (likely(!ctx->nr_counters))
-                goto out;
-        update_context_time(ctx);
-
-        perf_disable();
-        if (ctx->nr_active) {
-                list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-                        if (counter != counter->group_leader)
-                                counter_sched_out(counter, cpuctx, ctx);
-                        else
-                                group_sched_out(counter, cpuctx, ctx);
-                }
-        }
-        perf_enable();
- out:
-        spin_unlock(&ctx->lock);
-}
-
-/*
- * Test whether two contexts are equivalent, i.e. whether they
- * have both been cloned from the same version of the same context
- * and they both have the same number of enabled counters.
- * If the number of enabled counters is the same, then the set
- * of enabled counters should be the same, because these are both
- * inherited contexts, therefore we can't access individual counters
- * in them directly with an fd; we can only enable/disable all
- * counters via prctl, or enable/disable all counters in a family
- * via ioctl, which will have the same effect on both contexts.
- */
-static int context_equiv(struct perf_counter_context *ctx1,
-                         struct perf_counter_context *ctx2)
-{
-        return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
-                && ctx1->parent_gen == ctx2->parent_gen
-                && !ctx1->pin_count && !ctx2->pin_count;
-}
-
-static void __perf_counter_read(void *counter);
-
-static void __perf_counter_sync_stat(struct perf_counter *counter,
-                                     struct perf_counter *next_counter)
-{
-        u64 value;
-
-        if (!counter->attr.inherit_stat)
-                return;
-
-        /*
-         * Update the counter value, we cannot use perf_counter_read()
-         * because we're in the middle of a context switch and have IRQs
-         * disabled, which upsets smp_call_function_single(), however
-         * we know the counter must be on the current CPU, therefore we
-         * don't need to use it.
-         */
-        switch (counter->state) {
-        case PERF_COUNTER_STATE_ACTIVE:
-                __perf_counter_read(counter);
-                break;
-
-        case PERF_COUNTER_STATE_INACTIVE:
-                update_counter_times(counter);
-                break;
-
-        default:
-                break;
-        }
-
-        /*
-         * In order to keep per-task stats reliable we need to flip the counter
-         * values when we flip the contexts.
-         */
-        value = atomic64_read(&next_counter->count);
-        value = atomic64_xchg(&counter->count, value);
-        atomic64_set(&next_counter->count, value);
-
-        swap(counter->total_time_enabled, next_counter->total_time_enabled);
-        swap(counter->total_time_running, next_counter->total_time_running);
-
-        /*
-         * Since we swizzled the values, update the user visible data too.
-         */
-        perf_counter_update_userpage(counter);
-        perf_counter_update_userpage(next_counter);
-}
-
-#define list_next_entry(pos, member) \
-        list_entry(pos->member.next, typeof(*pos), member)
-
-static void perf_counter_sync_stat(struct perf_counter_context *ctx,
-                                   struct perf_counter_context *next_ctx)
-{
-        struct perf_counter *counter, *next_counter;
-
-        if (!ctx->nr_stat)
-                return;
-
-        counter = list_first_entry(&ctx->event_list,
-                                   struct perf_counter, event_entry);
-
-        next_counter = list_first_entry(&next_ctx->event_list,
-                                        struct perf_counter, event_entry);
-
-        while (&counter->event_entry != &ctx->event_list &&
-               &next_counter->event_entry != &next_ctx->event_list) {
-
-                __perf_counter_sync_stat(counter, next_counter);
-
-                counter = list_next_entry(counter, event_entry);
-                next_counter = list_next_entry(next_counter, event_entry);
-        }
-}
-
-/*
- * Called from scheduler to remove the counters of the current task,
- * with interrupts disabled.
- *
- * We stop each counter and update the counter value in counter->count.
- *
- * This does not protect us against NMI, but disable()
- * sets the disabled bit in the control field of counter _before_
- * accessing the counter control register. If a NMI hits, then it will
- * not restart the counter.
- */
-void perf_counter_task_sched_out(struct task_struct *task,
-                                 struct task_struct *next, int cpu)
-{
-        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
-        struct perf_counter_context *ctx = task->perf_counter_ctxp;
-        struct perf_counter_context *next_ctx;
-        struct perf_counter_context *parent;
-        struct pt_regs *regs;
-        int do_switch = 1;
-
-        regs = task_pt_regs(task);
-        perf_swcounter_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
-
-        if (likely(!ctx || !cpuctx->task_ctx))
-                return;
-
-        update_context_time(ctx);
-
-        rcu_read_lock();
-        parent = rcu_dereference(ctx->parent_ctx);
-        next_ctx = next->perf_counter_ctxp;
-        if (parent && next_ctx &&
-            rcu_dereference(next_ctx->parent_ctx) == parent) {
-                /*
-                 * Looks like the two contexts are clones, so we might be
-                 * able to optimize the context switch.  We lock both
-                 * contexts and check that they are clones under the
-                 * lock (including re-checking that neither has been
-                 * uncloned in the meantime).  It doesn't matter which
-                 * order we take the locks because no other cpu could
-                 * be trying to lock both of these tasks.
-                 */
-                spin_lock(&ctx->lock);
-                spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
-                if (context_equiv(ctx, next_ctx)) {
-                        /*
-                         * XXX do we need a memory barrier of sorts
-                         * wrt to rcu_dereference() of perf_counter_ctxp
-                         */
-                        task->perf_counter_ctxp = next_ctx;
-                        next->perf_counter_ctxp = ctx;
-                        ctx->task = next;
-                        next_ctx->task = task;
-                        do_switch = 0;
-
-                        perf_counter_sync_stat(ctx, next_ctx);
-                }
-                spin_unlock(&next_ctx->lock);
-                spin_unlock(&ctx->lock);
-        }
-        rcu_read_unlock();
-
-        if (do_switch) {
-                __perf_counter_sched_out(ctx, cpuctx);
-                cpuctx->task_ctx = NULL;
-        }
-}
-
-/*
- * Called with IRQs disabled
- */
-static void __perf_counter_task_sched_out(struct perf_counter_context *ctx)
-{
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-
-        if (!cpuctx->task_ctx)
-                return;
-
-        if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
-                return;
-
-        __perf_counter_sched_out(ctx, cpuctx);
-        cpuctx->task_ctx = NULL;
-}
-
-/*
- * Called with IRQs disabled
- */
-static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx)
-{
-        __perf_counter_sched_out(&cpuctx->ctx, cpuctx);
-}
-
-static void
-__perf_counter_sched_in(struct perf_counter_context *ctx,
-                        struct perf_cpu_context *cpuctx, int cpu)
-{
-        struct perf_counter *counter;
-        int can_add_hw = 1;
-
-        spin_lock(&ctx->lock);
-        ctx->is_active = 1;
-        if (likely(!ctx->nr_counters))
-                goto out;
-
-        ctx->timestamp = perf_clock();
-
-        perf_disable();
-
-        /*
-         * First go through the list and put on any pinned groups
-         * in order to give them the best chance of going on.
-         */
-        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-                if (counter->state <= PERF_COUNTER_STATE_OFF ||
-                    !counter->attr.pinned)
-                        continue;
-                if (counter->cpu != -1 && counter->cpu != cpu)
-                        continue;
-
-                if (counter != counter->group_leader)
-                        counter_sched_in(counter, cpuctx, ctx, cpu);
-                else {
-                        if (group_can_go_on(counter, cpuctx, 1))
-                                group_sched_in(counter, cpuctx, ctx, cpu);
-                }
-
-                /*
-                 * If this pinned group hasn't been scheduled,
-                 * put it in error state.
-                 */
-                if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
-                        update_group_times(counter);
-                        counter->state = PERF_COUNTER_STATE_ERROR;
-                }
-        }
-
-        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-                /*
-                 * Ignore counters in OFF or ERROR state, and
-                 * ignore pinned counters since we did them already.
-                 */
-                if (counter->state <= PERF_COUNTER_STATE_OFF ||
-                    counter->attr.pinned)
-                        continue;
-
-                /*
-                 * Listen to the 'cpu' scheduling filter constraint
-                 * of counters:
-                 */
-                if (counter->cpu != -1 && counter->cpu != cpu)
-                        continue;
-
-                if (counter != counter->group_leader) {
-                        if (counter_sched_in(counter, cpuctx, ctx, cpu))
-                                can_add_hw = 0;
-                } else {
-                        if (group_can_go_on(counter, cpuctx, can_add_hw)) {
-                                if (group_sched_in(counter, cpuctx, ctx, cpu))
-                                        can_add_hw = 0;
-                        }
-                }
-        }
-        perf_enable();
- out:
-        spin_unlock(&ctx->lock);
-}
-
-/*
- * Called from scheduler to add the counters of the current task
- * with interrupts disabled.
- *
- * We restore the counter value and then enable it.
- *
- * This does not protect us against NMI, but enable()
- * sets the enabled bit in the control field of counter _before_
- * accessing the counter control register. If a NMI hits, then it will
- * keep the counter running.
- */
-void perf_counter_task_sched_in(struct task_struct *task, int cpu)
-{
-        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
-        struct perf_counter_context *ctx = task->perf_counter_ctxp;
-
-        if (likely(!ctx))
-                return;
-        if (cpuctx->task_ctx == ctx)
-                return;
-        __perf_counter_sched_in(ctx, cpuctx, cpu);
-        cpuctx->task_ctx = ctx;
-}
-
-static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
-{
-        struct perf_counter_context *ctx = &cpuctx->ctx;
-
-        __perf_counter_sched_in(ctx, cpuctx, cpu);
-}
-
-#define MAX_INTERRUPTS (~0ULL)
-
-static void perf_log_throttle(struct perf_counter *counter, int enable);
-
-static void perf_adjust_period(struct perf_counter *counter, u64 events)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-        u64 period, sample_period;
-        s64 delta;
-
-        events *= hwc->sample_period;
-        period = div64_u64(events, counter->attr.sample_freq);
-
-        delta = (s64)(period - hwc->sample_period);
-        delta = (delta + 7) / 8; /* low pass filter */
-
-        sample_period = hwc->sample_period + delta;
-
-        if (!sample_period)
-                sample_period = 1;
-
-        hwc->sample_period = sample_period;
-}
-
-static void perf_ctx_adjust_freq(struct perf_counter_context *ctx)
-{
-        struct perf_counter *counter;
-        struct hw_perf_counter *hwc;
-        u64 interrupts, freq;
-
-        spin_lock(&ctx->lock);
-        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-                if (counter->state != PERF_COUNTER_STATE_ACTIVE)
-                        continue;
-
-                hwc = &counter->hw;
-
-                interrupts = hwc->interrupts;
-                hwc->interrupts = 0;
-
-                /*
-                 * unthrottle counters on the tick
-                 */
-                if (interrupts == MAX_INTERRUPTS) {
-                        perf_log_throttle(counter, 1);
-                        counter->pmu->unthrottle(counter);
-                        interrupts = 2*sysctl_perf_counter_sample_rate/HZ;
-                }
-
-                if (!counter->attr.freq || !counter->attr.sample_freq)
-                        continue;
-
-                /*
-                 * if the specified freq < HZ then we need to skip ticks
-                 */
-                if (counter->attr.sample_freq < HZ) {
-                        freq = counter->attr.sample_freq;
-
-                        hwc->freq_count += freq;
-                        hwc->freq_interrupts += interrupts;
-
-                        if (hwc->freq_count < HZ)
-                                continue;
-
-                        interrupts = hwc->freq_interrupts;
-                        hwc->freq_interrupts = 0;
-                        hwc->freq_count -= HZ;
-                } else
-                        freq = HZ;
-
-                perf_adjust_period(counter, freq * interrupts);
-
-                /*
-                 * In order to avoid being stalled by an (accidental) huge
-                 * sample period, force reset the sample period if we didn't
-                 * get any events in this freq period.
-                 */
-                if (!interrupts) {
-                        perf_disable();
-                        counter->pmu->disable(counter);
-                        atomic64_set(&hwc->period_left, 0);
-                        counter->pmu->enable(counter);
-                        perf_enable();
-                }
-        }
-        spin_unlock(&ctx->lock);
-}
-
-/*
- * Round-robin a context's counters:
- */
-static void rotate_ctx(struct perf_counter_context *ctx)
-{
-        struct perf_counter *counter;
-
-        if (!ctx->nr_counters)
-                return;
-
-        spin_lock(&ctx->lock);
-        /*
-         * Rotate the first entry last (works just fine for group counters too):
-         */
-        perf_disable();
-        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-                list_move_tail(&counter->list_entry, &ctx->counter_list);
-                break;
-        }
-        perf_enable();
-
-        spin_unlock(&ctx->lock);
-}
-
-void perf_counter_task_tick(struct task_struct *curr, int cpu)
-{
-        struct perf_cpu_context *cpuctx;
-        struct perf_counter_context *ctx;
-
-        if (!atomic_read(&nr_counters))
-                return;
-
-        cpuctx = &per_cpu(perf_cpu_context, cpu);
-        ctx = curr->perf_counter_ctxp;
-
-        perf_ctx_adjust_freq(&cpuctx->ctx);
-        if (ctx)
-                perf_ctx_adjust_freq(ctx);
-
-        perf_counter_cpu_sched_out(cpuctx);
-        if (ctx)
-                __perf_counter_task_sched_out(ctx);
-
-        rotate_ctx(&cpuctx->ctx);
-        if (ctx)
-                rotate_ctx(ctx);
-
-        perf_counter_cpu_sched_in(cpuctx, cpu);
-        if (ctx)
-                perf_counter_task_sched_in(curr, cpu);
-}
-
-/*
- * Enable all of a task's counters that have been marked enable-on-exec.
- * This expects task == current.
- */
-static void perf_counter_enable_on_exec(struct task_struct *task)
-{
-        struct perf_counter_context *ctx;
-        struct perf_counter *counter;
-        unsigned long flags;
-        int enabled = 0;
-
-        local_irq_save(flags);
-        ctx = task->perf_counter_ctxp;
-        if (!ctx || !ctx->nr_counters)
-                goto out;
-
-        __perf_counter_task_sched_out(ctx);
-
-        spin_lock(&ctx->lock);
-
-        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-                if (!counter->attr.enable_on_exec)
-                        continue;
-                counter->attr.enable_on_exec = 0;
-                if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
-                        continue;
-                __perf_counter_mark_enabled(counter, ctx);
-                enabled = 1;
-        }
-
-        /*
-         * Unclone this context if we enabled any counter.
-         */
-        if (enabled)
-                unclone_ctx(ctx);
-
-        spin_unlock(&ctx->lock);
-
-        perf_counter_task_sched_in(task, smp_processor_id());
- out:
-        local_irq_restore(flags);
-}
-
-/*
- * Cross CPU call to read the hardware counter
- */
-static void __perf_counter_read(void *info)
-{
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-        struct perf_counter *counter = info;
-        struct perf_counter_context *ctx = counter->ctx;
-        unsigned long flags;
-
-        /*
-         * If this is a task context, we need to check whether it is
-         * the current task context of this cpu.  If not it has been
-         * scheduled out before the smp call arrived.  In that case
-         * counter->count would have been updated to a recent sample
-         * when the counter was scheduled out.
-         */
-        if (ctx->task && cpuctx->task_ctx != ctx)
-                return;
-
-        local_irq_save(flags);
-        if (ctx->is_active)
-                update_context_time(ctx);
-        counter->pmu->read(counter);
-        update_counter_times(counter);
-        local_irq_restore(flags);
-}
-
-static u64 perf_counter_read(struct perf_counter *counter)
-{
-        /*
-         * If counter is enabled and currently active on a CPU, update the
-         * value in the counter structure:
-         */
-        if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
-                smp_call_function_single(counter->oncpu,
-                                         __perf_counter_read, counter, 1);
-        } else if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
-                update_counter_times(counter);
-        }
-
-        return atomic64_read(&counter->count);
-}
-
-/*
- * Initialize the perf_counter context in a task_struct:
- */
-static void
-__perf_counter_init_context(struct perf_counter_context *ctx,
-                            struct task_struct *task)
-{
-        memset(ctx, 0, sizeof(*ctx));
-        spin_lock_init(&ctx->lock);
-        mutex_init(&ctx->mutex);
-        INIT_LIST_HEAD(&ctx->counter_list);
-        INIT_LIST_HEAD(&ctx->event_list);
-        atomic_set(&ctx->refcount, 1);
-        ctx->task = task;
-}
-
-static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
-{
-        struct perf_counter_context *ctx;
-        struct perf_cpu_context *cpuctx;
-        struct task_struct *task;
-        unsigned long flags;
-        int err;
-
-        /*
-         * If cpu is not a wildcard then this is a percpu counter:
-         */
-        if (cpu != -1) {
-                /* Must be root to operate on a CPU counter: */
-                if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
-                        return ERR_PTR(-EACCES);
-
-                if (cpu < 0 || cpu > num_possible_cpus())
-                        return ERR_PTR(-EINVAL);
-
-                /*
-                 * We could be clever and allow to attach a counter to an
-                 * offline CPU and activate it when the CPU comes up, but
-                 * that's for later.
-                 */
-                if (!cpu_isset(cpu, cpu_online_map))
-                        return ERR_PTR(-ENODEV);
-
-                cpuctx = &per_cpu(perf_cpu_context, cpu);
-                ctx = &cpuctx->ctx;
-                get_ctx(ctx);
-
-                return ctx;
-        }
-
-        rcu_read_lock();
-        if (!pid)
-                task = current;
-        else
-                task = find_task_by_vpid(pid);
-        if (task)
-                get_task_struct(task);
-        rcu_read_unlock();
-
-        if (!task)
-                return ERR_PTR(-ESRCH);
-
-        /*
-         * Can't attach counters to a dying task.
-         */
-        err = -ESRCH;
-        if (task->flags & PF_EXITING)
-                goto errout;
-
-        /* Reuse ptrace permission checks for now. */
-        err = -EACCES;
-        if (!ptrace_may_access(task, PTRACE_MODE_READ))
-                goto errout;
-
- retry:
-        ctx = perf_lock_task_context(task, &flags);
-        if (ctx) {
-                unclone_ctx(ctx);
-                spin_unlock_irqrestore(&ctx->lock, flags);
-        }
-
-        if (!ctx) {
-                ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL);
-                err = -ENOMEM;
-                if (!ctx)
-                        goto errout;
-                __perf_counter_init_context(ctx, task);
-                get_ctx(ctx);
-                if (cmpxchg(&task->perf_counter_ctxp, NULL, ctx)) {
-                        /*
-                         * We raced with some other task; use
-                         * the context they set.
-                         */
-                        kfree(ctx);
-                        goto retry;
-                }
-                get_task_struct(task);
-        }
-
-        put_task_struct(task);
-        return ctx;
-
- errout:
-        put_task_struct(task);
-        return ERR_PTR(err);
-}
-
-static void free_counter_rcu(struct rcu_head *head)
-{
-        struct perf_counter *counter;
-
-        counter = container_of(head, struct perf_counter, rcu_head);
-        if (counter->ns)
-                put_pid_ns(counter->ns);
-        kfree(counter);
-}
-
-static void perf_pending_sync(struct perf_counter *counter);
-
-static void free_counter(struct perf_counter *counter)
-{
-        perf_pending_sync(counter);
-
-        if (!counter->parent) {
-                atomic_dec(&nr_counters);
-                if (counter->attr.mmap)
-                        atomic_dec(&nr_mmap_counters);
-                if (counter->attr.comm)
-                        atomic_dec(&nr_comm_counters);
-                if (counter->attr.task)
-                        atomic_dec(&nr_task_counters);
-        }
-
-        if (counter->output) {
-                fput(counter->output->filp);
-                counter->output = NULL;
-        }
-
-        if (counter->destroy)
-                counter->destroy(counter);
-
-        put_ctx(counter->ctx);
-        call_rcu(&counter->rcu_head, free_counter_rcu);
-}
-
-/*
- * Called when the last reference to the file is gone.
- */
-static int perf_release(struct inode *inode, struct file *file)
-{
-        struct perf_counter *counter = file->private_data;
-        struct perf_counter_context *ctx = counter->ctx;
-
-        file->private_data = NULL;
-
-        WARN_ON_ONCE(ctx->parent_ctx);
-        mutex_lock(&ctx->mutex);
-        perf_counter_remove_from_context(counter);
-        mutex_unlock(&ctx->mutex);
-
-        mutex_lock(&counter->owner->perf_counter_mutex);
-        list_del_init(&counter->owner_entry);
-        mutex_unlock(&counter->owner->perf_counter_mutex);
-        put_task_struct(counter->owner);
-
-        free_counter(counter);
-
-        return 0;
-}
-
-static int perf_counter_read_size(struct perf_counter *counter)
-{
-        int entry = sizeof(u64); /* value */
-        int size = 0;
-        int nr = 1;
-
-        if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
-                size += sizeof(u64);
-
-        if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
-                size += sizeof(u64);
-
-        if (counter->attr.read_format & PERF_FORMAT_ID)
-                entry += sizeof(u64);
-
-        if (counter->attr.read_format & PERF_FORMAT_GROUP) {
-                nr += counter->group_leader->nr_siblings;
-                size += sizeof(u64);
-        }
-
-        size += entry * nr;
-
-        return size;
-}
-
-static u64 perf_counter_read_value(struct perf_counter *counter)
-{
-        struct perf_counter *child;
-        u64 total = 0;
-
-        total += perf_counter_read(counter);
-        list_for_each_entry(child, &counter->child_list, child_list)
-                total += perf_counter_read(child);
-
-        return total;
-}
-
-static int perf_counter_read_entry(struct perf_counter *counter,
-                                   u64 read_format, char __user *buf)
-{
-        int n = 0, count = 0;
-        u64 values[2];
-
-        values[n++] = perf_counter_read_value(counter);
-        if (read_format & PERF_FORMAT_ID)
-                values[n++] = primary_counter_id(counter);
-
-        count = n * sizeof(u64);
-
-        if (copy_to_user(buf, values, count))
-                return -EFAULT;
-
-        return count;
-}
-
-static int perf_counter_read_group(struct perf_counter *counter,
-                                   u64 read_format, char __user *buf)
-{
-        struct perf_counter *leader = counter->group_leader, *sub;
-        int n = 0, size = 0, err = -EFAULT;
-        u64 values[3];
-
-        values[n++] = 1 + leader->nr_siblings;
-        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-                values[n++] = leader->total_time_enabled +
-                        atomic64_read(&leader->child_total_time_enabled);
-        }
-        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-                values[n++] = leader->total_time_running +
-                        atomic64_read(&leader->child_total_time_running);
-        }
-
-        size = n * sizeof(u64);
-
-        if (copy_to_user(buf, values, size))
-                return -EFAULT;
-
-        err = perf_counter_read_entry(leader, read_format, buf + size);
-        if (err < 0)
-                return err;
-
-        size += err;
-
-        list_for_each_entry(sub, &leader->sibling_list, list_entry) {
-                err = perf_counter_read_entry(sub, read_format,
-                                buf + size);
-                if (err < 0)
-                        return err;
-
-                size += err;
-        }
-
-        return size;
-}
-
-static int perf_counter_read_one(struct perf_counter *counter,
-                                 u64 read_format, char __user *buf)
-{
-        u64 values[4];
-        int n = 0;
-
-        values[n++] = perf_counter_read_value(counter);
-        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-                values[n++] = counter->total_time_enabled +
-                        atomic64_read(&counter->child_total_time_enabled);
-        }
-        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-                values[n++] = counter->total_time_running +
-                        atomic64_read(&counter->child_total_time_running);
-        }
-        if (read_format & PERF_FORMAT_ID)
-                values[n++] = primary_counter_id(counter);
-
-        if (copy_to_user(buf, values, n * sizeof(u64)))
-                return -EFAULT;
-
-        return n * sizeof(u64);
-}
-
-/*
- * Read the performance counter - simple non blocking version for now
- */
-static ssize_t
-perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
-{
-        u64 read_format = counter->attr.read_format;
-        int ret;
-
-        /*
-         * Return end-of-file for a read on a counter that is in
-         * error state (i.e. because it was pinned but it couldn't be
-         * scheduled on to the CPU at some point).
-         */
-        if (counter->state == PERF_COUNTER_STATE_ERROR)
-                return 0;
-
-        if (count < perf_counter_read_size(counter))
-                return -ENOSPC;
-
-        WARN_ON_ONCE(counter->ctx->parent_ctx);
-        mutex_lock(&counter->child_mutex);
-        if (read_format & PERF_FORMAT_GROUP)
-                ret = perf_counter_read_group(counter, read_format, buf);
-        else
-                ret = perf_counter_read_one(counter, read_format, buf);
-        mutex_unlock(&counter->child_mutex);
-
-        return ret;
-}
-
-static ssize_t
-perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
-        struct perf_counter *counter = file->private_data;
-
-        return perf_read_hw(counter, buf, count);
-}
-
-static unsigned int perf_poll(struct file *file, poll_table *wait)
-{
-        struct perf_counter *counter = file->private_data;
-        struct perf_mmap_data *data;
-        unsigned int events = POLL_HUP;
-
-        rcu_read_lock();
-        data = rcu_dereference(counter->data);
-        if (data)
-                events = atomic_xchg(&data->poll, 0);
-        rcu_read_unlock();
-
-        poll_wait(file, &counter->waitq, wait);
-
-        return events;
-}
-
-static void perf_counter_reset(struct perf_counter *counter)
-{
-        (void)perf_counter_read(counter);
-        atomic64_set(&counter->count, 0);
-        perf_counter_update_userpage(counter);
-}
-
-/*
- * Holding the top-level counter's child_mutex means that any
- * descendant process that has inherited this counter will block
- * in sync_child_counter if it goes to exit, thus satisfying the
- * task existence requirements of perf_counter_enable/disable.
- */
-static void perf_counter_for_each_child(struct perf_counter *counter,
-                                        void (*func)(struct perf_counter *))
-{
-        struct perf_counter *child;
-
-        WARN_ON_ONCE(counter->ctx->parent_ctx);
-        mutex_lock(&counter->child_mutex);
-        func(counter);
-        list_for_each_entry(child, &counter->child_list, child_list)
-                func(child);
-        mutex_unlock(&counter->child_mutex);
-}
-
-static void perf_counter_for_each(struct perf_counter *counter,
-                                  void (*func)(struct perf_counter *))
-{
-        struct perf_counter_context *ctx = counter->ctx;
-        struct perf_counter *sibling;
-
-        WARN_ON_ONCE(ctx->parent_ctx);
-        mutex_lock(&ctx->mutex);
-        counter = counter->group_leader;
-
-        perf_counter_for_each_child(counter, func);
-        func(counter);
-        list_for_each_entry(sibling, &counter->sibling_list, list_entry)
-                perf_counter_for_each_child(counter, func);
-        mutex_unlock(&ctx->mutex);
-}
-
-static int perf_counter_period(struct perf_counter *counter, u64 __user *arg)
-{
-        struct perf_counter_context *ctx = counter->ctx;
-        unsigned long size;
-        int ret = 0;
-        u64 value;
-
-        if (!counter->attr.sample_period)
-                return -EINVAL;
-
-        size = copy_from_user(&value, arg, sizeof(value));
-        if (size != sizeof(value))
-                return -EFAULT;
-
-        if (!value)
-                return -EINVAL;
-
-        spin_lock_irq(&ctx->lock);
-        if (counter->attr.freq) {
-                if (value > sysctl_perf_counter_sample_rate) {
-                        ret = -EINVAL;
-                        goto unlock;
-                }
-
-                counter->attr.sample_freq = value;
-        } else {
-                counter->attr.sample_period = value;
-                counter->hw.sample_period = value;
-        }
-unlock:
-        spin_unlock_irq(&ctx->lock);
-
-        return ret;
-}
-
-int perf_counter_set_output(struct perf_counter *counter, int output_fd);
-
-static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
-        struct perf_counter *counter = file->private_data;
-        void (*func)(struct perf_counter *);
-        u32 flags = arg;
-
-        switch (cmd) {
-        case PERF_COUNTER_IOC_ENABLE:
-                func = perf_counter_enable;
-                break;
-        case PERF_COUNTER_IOC_DISABLE:
-                func = perf_counter_disable;
-                break;
-        case PERF_COUNTER_IOC_RESET:
-                func = perf_counter_reset;
-                break;
-
-        case PERF_COUNTER_IOC_REFRESH:
-                return perf_counter_refresh(counter, arg);
-
-        case PERF_COUNTER_IOC_PERIOD:
-                return perf_counter_period(counter, (u64 __user *)arg);
-
-        case PERF_COUNTER_IOC_SET_OUTPUT:
-                return perf_counter_set_output(counter, arg);
-
-        default:
-                return -ENOTTY;
-        }
-
-        if (flags & PERF_IOC_FLAG_GROUP)
-                perf_counter_for_each(counter, func);
-        else
-                perf_counter_for_each_child(counter, func);
-
-        return 0;
-}
-
-int perf_counter_task_enable(void)
-{
-        struct perf_counter *counter;
-
-        mutex_lock(&current->perf_counter_mutex);
-        list_for_each_entry(counter, &current->perf_counter_list, owner_entry)
-                perf_counter_for_each_child(counter, perf_counter_enable);
-        mutex_unlock(&current->perf_counter_mutex);
-
-        return 0;
-}
-
-int perf_counter_task_disable(void)
-{
-        struct perf_counter *counter;
-
-        mutex_lock(&current->perf_counter_mutex);
-        list_for_each_entry(counter, &current->perf_counter_list, owner_entry)
-                perf_counter_for_each_child(counter, perf_counter_disable);
-        mutex_unlock(&current->perf_counter_mutex);
-
-        return 0;
-}
-
-#ifndef PERF_COUNTER_INDEX_OFFSET
-# define PERF_COUNTER_INDEX_OFFSET 0
-#endif
-
-static int perf_counter_index(struct perf_counter *counter)
-{
-        if (counter->state != PERF_COUNTER_STATE_ACTIVE)
-                return 0;
-
-        return counter->hw.idx + 1 - PERF_COUNTER_INDEX_OFFSET;
-}
-
-/*
- * Callers need to ensure there can be no nesting of this function, otherwise
- * the seqlock logic goes bad. We can not serialize this because the arch
- * code calls this from NMI context.
- */
-void perf_counter_update_userpage(struct perf_counter *counter)
-{
-        struct perf_counter_mmap_page *userpg;
-        struct perf_mmap_data *data;
-
-        rcu_read_lock();
-        data = rcu_dereference(counter->data);
-        if (!data)
-                goto unlock;
-
-        userpg = data->user_page;
-
-        /*
-         * Disable preemption so as to not let the corresponding user-space
-         * spin too long if we get preempted.
-         */
-        preempt_disable();
-        ++userpg->lock;
-        barrier();
-        userpg->index = perf_counter_index(counter);
-        userpg->offset = atomic64_read(&counter->count);
-        if (counter->state == PERF_COUNTER_STATE_ACTIVE)
-                userpg->offset -= atomic64_read(&counter->hw.prev_count);
-
-        userpg->time_enabled = counter->total_time_enabled +
-                        atomic64_read(&counter->child_total_time_enabled);
-
-        userpg->time_running = counter->total_time_running +
-                        atomic64_read(&counter->child_total_time_running);
-
-        barrier();
-        ++userpg->lock;
-        preempt_enable();
-unlock:
-        rcu_read_unlock();
-}
-
-static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-        struct perf_counter *counter = vma->vm_file->private_data;
-        struct perf_mmap_data *data;
-        int ret = VM_FAULT_SIGBUS;
-
-        if (vmf->flags & FAULT_FLAG_MKWRITE) {
-                if (vmf->pgoff == 0)
-                        ret = 0;
-                return ret;
-        }
-
-        rcu_read_lock();
-        data = rcu_dereference(counter->data);
-        if (!data)
-                goto unlock;
-
-        if (vmf->pgoff == 0) {
-                vmf->page = virt_to_page(data->user_page);
-        } else {
-                int nr = vmf->pgoff - 1;
-
-                if ((unsigned)nr > data->nr_pages)
-                        goto unlock;
-
-                if (vmf->flags & FAULT_FLAG_WRITE)
-                        goto unlock;
-
-                vmf->page = virt_to_page(data->data_pages[nr]);
-        }
-
-        get_page(vmf->page);
-        vmf->page->mapping = vma->vm_file->f_mapping;
-        vmf->page->index   = vmf->pgoff;
-
-        ret = 0;
-unlock:
-        rcu_read_unlock();
-
-        return ret;
-}
-
-static int perf_mmap_data_alloc(struct perf_counter *counter, int nr_pages)
-{
-        struct perf_mmap_data *data;
-        unsigned long size;
-        int i;
-
-        WARN_ON(atomic_read(&counter->mmap_count));
-
-        size = sizeof(struct perf_mmap_data);
-        size += nr_pages * sizeof(void *);
-
-        data = kzalloc(size, GFP_KERNEL);
-        if (!data)
-                goto fail;
-
-        data->user_page = (void *)get_zeroed_page(GFP_KERNEL);
-        if (!data->user_page)
-                goto fail_user_page;
-
-        for (i = 0; i < nr_pages; i++) {
-                data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
-                if (!data->data_pages[i])
-                        goto fail_data_pages;
-        }
-
-        data->nr_pages = nr_pages;
-        atomic_set(&data->lock, -1);
-
-        rcu_assign_pointer(counter->data, data);
-
-        return 0;
-
-fail_data_pages:
-        for (i--; i >= 0; i--)
-                free_page((unsigned long)data->data_pages[i]);
-
-        free_page((unsigned long)data->user_page);
-
-fail_user_page:
-        kfree(data);
-
-fail:
-        return -ENOMEM;
-}
-
-static void perf_mmap_free_page(unsigned long addr)
-{
-        struct page *page = virt_to_page((void *)addr);
-
-        page->mapping = NULL;
-        __free_page(page);
-}
-
-static void __perf_mmap_data_free(struct rcu_head *rcu_head)
-{
-        struct perf_mmap_data *data;
-        int i;
-
-        data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
-
-        perf_mmap_free_page((unsigned long)data->user_page);
-        for (i = 0; i < data->nr_pages; i++)
-                perf_mmap_free_page((unsigned long)data->data_pages[i]);
-
-        kfree(data);
-}
-
-static void perf_mmap_data_free(struct perf_counter *counter)
-{
-        struct perf_mmap_data *data = counter->data;
-
-        WARN_ON(atomic_read(&counter->mmap_count));
-
-        rcu_assign_pointer(counter->data, NULL);
-        call_rcu(&data->rcu_head, __perf_mmap_data_free);
-}
-
-static void perf_mmap_open(struct vm_area_struct *vma)
-{
-        struct perf_counter *counter = vma->vm_file->private_data;
-
-        atomic_inc(&counter->mmap_count);
-}
-
-static void perf_mmap_close(struct vm_area_struct *vma)
-{
-        struct perf_counter *counter = vma->vm_file->private_data;
-
-        WARN_ON_ONCE(counter->ctx->parent_ctx);
-        if (atomic_dec_and_mutex_lock(&counter->mmap_count, &counter->mmap_mutex)) {
-                struct user_struct *user = current_user();
-
-                atomic_long_sub(counter->data->nr_pages + 1, &user->locked_vm);
-                vma->vm_mm->locked_vm -= counter->data->nr_locked;
-                perf_mmap_data_free(counter);
-                mutex_unlock(&counter->mmap_mutex);
-        }
-}
-
-static struct vm_operations_struct perf_mmap_vmops = {
-        .open           = perf_mmap_open,
-        .close          = perf_mmap_close,
-        .fault          = perf_mmap_fault,
-        .page_mkwrite   = perf_mmap_fault,
-};
-
-static int perf_mmap(struct file *file, struct vm_area_struct *vma)
-{
-        struct perf_counter *counter = file->private_data;
-        unsigned long user_locked, user_lock_limit;
-        struct user_struct *user = current_user();
-        unsigned long locked, lock_limit;
-        unsigned long vma_size;
-        unsigned long nr_pages;
-        long user_extra, extra;
-        int ret = 0;
-
-        if (!(vma->vm_flags & VM_SHARED))
-                return -EINVAL;
-
-        vma_size = vma->vm_end - vma->vm_start;
-        nr_pages = (vma_size / PAGE_SIZE) - 1;
-
-        /*
-         * If we have data pages ensure they're a power-of-two number, so we
-         * can do bitmasks instead of modulo.
-         */
-        if (nr_pages != 0 && !is_power_of_2(nr_pages))
-                return -EINVAL;
-
-        if (vma_size != PAGE_SIZE * (1 + nr_pages))
-                return -EINVAL;
-
-        if (vma->vm_pgoff != 0)
-                return -EINVAL;
-
-        WARN_ON_ONCE(counter->ctx->parent_ctx);
-        mutex_lock(&counter->mmap_mutex);
-        if (counter->output) {
-                ret = -EINVAL;
-                goto unlock;
-        }
-
-        if (atomic_inc_not_zero(&counter->mmap_count)) {
-                if (nr_pages != counter->data->nr_pages)
-                        ret = -EINVAL;
-                goto unlock;
-        }
-
-        user_extra = nr_pages + 1;
-        user_lock_limit = sysctl_perf_counter_mlock >> (PAGE_SHIFT - 10);
-
-        /*
-         * Increase the limit linearly with more CPUs:
-         */
-        user_lock_limit *= num_online_cpus();
-
-        user_locked = atomic_long_read(&user->locked_vm) + user_extra;
-
-        extra = 0;
-        if (user_locked > user_lock_limit)
-                extra = user_locked - user_lock_limit;
-
-        lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
-        lock_limit >>= PAGE_SHIFT;
-        locked = vma->vm_mm->locked_vm + extra;
-
-        if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
-                ret = -EPERM;
-                goto unlock;
-        }
-
-        WARN_ON(counter->data);
-        ret = perf_mmap_data_alloc(counter, nr_pages);
-        if (ret)
-                goto unlock;
-
-        atomic_set(&counter->mmap_count, 1);
-        atomic_long_add(user_extra, &user->locked_vm);
-        vma->vm_mm->locked_vm += extra;
-        counter->data->nr_locked = extra;
-        if (vma->vm_flags & VM_WRITE)
-                counter->data->writable = 1;
-
-unlock:
-        mutex_unlock(&counter->mmap_mutex);
-
-        vma->vm_flags |= VM_RESERVED;
-        vma->vm_ops = &perf_mmap_vmops;
-
-        return ret;
-}
-
-static int perf_fasync(int fd, struct file *filp, int on)
-{
-        struct inode *inode = filp->f_path.dentry->d_inode;
-        struct perf_counter *counter = filp->private_data;
-        int retval;
-
-        mutex_lock(&inode->i_mutex);
-        retval = fasync_helper(fd, filp, on, &counter->fasync);
-        mutex_unlock(&inode->i_mutex);
-
-        if (retval < 0)
-                return retval;
-
-        return 0;
-}
-
-static const struct file_operations perf_fops = {
-        .release                = perf_release,
-        .read                   = perf_read,
-        .poll                   = perf_poll,
-        .unlocked_ioctl         = perf_ioctl,
-        .compat_ioctl           = perf_ioctl,
-        .mmap                   = perf_mmap,
-        .fasync                 = perf_fasync,
-};
-
-/*
- * Perf counter wakeup
- *
- * If there's data, ensure we set the poll() state and publish everything
- * to user-space before waking everybody up.
- */
-
-void perf_counter_wakeup(struct perf_counter *counter)
-{
-        wake_up_all(&counter->waitq);
-
-        if (counter->pending_kill) {
-                kill_fasync(&counter->fasync, SIGIO, counter->pending_kill);
-                counter->pending_kill = 0;
-        }
-}
-
-/*
- * Pending wakeups
- *
- * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
- *
- * The NMI bit means we cannot possibly take locks. Therefore, maintain a
- * single linked list and use cmpxchg() to add entries lockless.
- */
-
-static void perf_pending_counter(struct perf_pending_entry *entry)
-{
-        struct perf_counter *counter = container_of(entry,
-                        struct perf_counter, pending);
-
-        if (counter->pending_disable) {
-                counter->pending_disable = 0;
-                __perf_counter_disable(counter);
-        }
-
-        if (counter->pending_wakeup) {
-                counter->pending_wakeup = 0;
-                perf_counter_wakeup(counter);
-        }
-}
-
-#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
-
-static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
-        PENDING_TAIL,
-};
-
-static void perf_pending_queue(struct perf_pending_entry *entry,
-                               void (*func)(struct perf_pending_entry *))
-{
-        struct perf_pending_entry **head;
-
-        if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
-                return;
-
-        entry->func = func;
-
-        head = &get_cpu_var(perf_pending_head);
-
-        do {
-                entry->next = *head;
-        } while (cmpxchg(head, entry->next, entry) != entry->next);
-
-        set_perf_counter_pending();
-
-        put_cpu_var(perf_pending_head);
-}
-
-static int __perf_pending_run(void)
-{
-        struct perf_pending_entry *list;
-        int nr = 0;
-
-        list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
-        while (list != PENDING_TAIL) {
-                void (*func)(struct perf_pending_entry *);
-                struct perf_pending_entry *entry = list;
-
-                list = list->next;
-
-                func = entry->func;
-                entry->next = NULL;
-                /*
-                 * Ensure we observe the unqueue before we issue the wakeup,
-                 * so that we won't be waiting forever.
-                 * -- see perf_not_pending().
-                 */
-                smp_wmb();
-
-                func(entry);
-                nr++;
-        }
-
-        return nr;
-}
-
-static inline int perf_not_pending(struct perf_counter *counter)
-{
-        /*
-         * If we flush on whatever cpu we run, there is a chance we don't
-         * need to wait.
-         */
-        get_cpu();
-        __perf_pending_run();
-        put_cpu();
-
-        /*
-         * Ensure we see the proper queue state before going to sleep
-         * so that we do not miss the wakeup. -- see perf_pending_handle()
-         */
-        smp_rmb();
-        return counter->pending.next == NULL;
-}
-
-static void perf_pending_sync(struct perf_counter *counter)
-{
-        wait_event(counter->waitq, perf_not_pending(counter));
-}
-
-void perf_counter_do_pending(void)
-{
-        __perf_pending_run();
-}
-
-/*
- * Callchain support -- arch specific
- */
-
-__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
-{
-        return NULL;
-}
-
-/*
- * Output
- */
-
-struct perf_output_handle {
-        struct perf_counter     *counter;
-        struct perf_mmap_data   *data;
-        unsigned long           head;
-        unsigned long           offset;
-        int                     nmi;
-        int                     sample;
-        int                     locked;
-        unsigned long           flags;
-};
-
-static bool perf_output_space(struct perf_mmap_data *data,
-                              unsigned int offset, unsigned int head)
-{
-        unsigned long tail;
-        unsigned long mask;
-
-        if (!data->writable)
-                return true;
-
-        mask = (data->nr_pages << PAGE_SHIFT) - 1;
-        /*
-         * Userspace could choose to issue a mb() before updating the tail
-         * pointer. So that all reads will be completed before the write is
-         * issued.
-         */
-        tail = ACCESS_ONCE(data->user_page->data_tail);
-        smp_rmb();
-
-        offset = (offset - tail) & mask;
-        head   = (head   - tail) & mask;
-
-        if ((int)(head - offset) < 0)
-                return false;
-
-        return true;
-}
-
-static void perf_output_wakeup(struct perf_output_handle *handle)
-{
-        atomic_set(&handle->data->poll, POLL_IN);
-
-        if (handle->nmi) {
-                handle->counter->pending_wakeup = 1;
-                perf_pending_queue(&handle->counter->pending,
-                                   perf_pending_counter);
-        } else
-                perf_counter_wakeup(handle->counter);
-}
-
-/*
- * Curious locking construct.
- *
- * We need to ensure a later event doesn't publish a head when a former
- * event isn't done writing. However since we need to deal with NMIs we
- * cannot fully serialize things.
- *
- * What we do is serialize between CPUs so we only have to deal with NMI
- * nesting on a single CPU.
- *
- * We only publish the head (and generate a wakeup) when the outer-most
- * event completes.
- */
-static void perf_output_lock(struct perf_output_handle *handle)
-{
-        struct perf_mmap_data *data = handle->data;
-        int cpu;
-
-        handle->locked = 0;
-
-        local_irq_save(handle->flags);
-        cpu = smp_processor_id();
-
-        if (in_nmi() && atomic_read(&data->lock) == cpu)
-                return;
-
-        while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
-                cpu_relax();
-
-        handle->locked = 1;
-}
-
-static void perf_output_unlock(struct perf_output_handle *handle)
-{
-        struct perf_mmap_data *data = handle->data;
-        unsigned long head;
-        int cpu;
-
-        data->done_head = data->head;
-
-        if (!handle->locked)
-                goto out;
-
-again:
-        /*
-         * The xchg implies a full barrier that ensures all writes are done
-         * before we publish the new head, matched by a rmb() in userspace when
-         * reading this position.
-         */
-        while ((head = atomic_long_xchg(&data->done_head, 0)))
-                data->user_page->data_head = head;
-
-        /*
-         * NMI can happen here, which means we can miss a done_head update.
-         */
-
-        cpu = atomic_xchg(&data->lock, -1);
-        WARN_ON_ONCE(cpu != smp_processor_id());
-
-        /*
-         * Therefore we have to validate we did not indeed do so.
-         */
-        if (unlikely(atomic_long_read(&data->done_head))) {
-                /*
-                 * Since we had it locked, we can lock it again.
-                 */
-                while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
-                        cpu_relax();
-
-                goto again;
-        }
-
-        if (atomic_xchg(&data->wakeup, 0))
-                perf_output_wakeup(handle);
-out:
-        local_irq_restore(handle->flags);
-}
-
-static void perf_output_copy(struct perf_output_handle *handle,
-                             const void *buf, unsigned int len)
-{
-        unsigned int pages_mask;
-        unsigned int offset;
-        unsigned int size;
-        void **pages;
-
-        offset          = handle->offset;
-        pages_mask      = handle->data->nr_pages - 1;
-        pages           = handle->data->data_pages;
-
-        do {
-                unsigned int page_offset;
-                int nr;
-
-                nr          = (offset >> PAGE_SHIFT) & pages_mask;
-                page_offset = offset & (PAGE_SIZE - 1);
-                size        = min_t(unsigned int, PAGE_SIZE - page_offset, len);
-
-                memcpy(pages[nr] + page_offset, buf, size);
-
-                len         -= size;
-                buf         += size;
-                offset      += size;
-        } while (len);
-
-        handle->offset = offset;
-
-        /*
-         * Check we didn't copy past our reservation window, taking the
-         * possible unsigned int wrap into account.
-         */
-        WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
-}
-
-#define perf_output_put(handle, x) \
-        perf_output_copy((handle), &(x), sizeof(x))
-
-static int perf_output_begin(struct perf_output_handle *handle,
-                             struct perf_counter *counter, unsigned int size,
-                             int nmi, int sample)
-{
-        struct perf_counter *output_counter;
-        struct perf_mmap_data *data;
-        unsigned int offset, head;
-        int have_lost;
-        struct {
-                struct perf_event_header header;
-                u64                      id;
-                u64                      lost;
-        } lost_event;
-
-        rcu_read_lock();
-        /*
-         * For inherited counters we send all the output towards the parent.
-         */
-        if (counter->parent)
-                counter = counter->parent;
-
-        output_counter = rcu_dereference(counter->output);
-        if (output_counter)
-                counter = output_counter;
-
-        data = rcu_dereference(counter->data);
-        if (!data)
-                goto out;
-
-        handle->data    = data;
-        handle->counter = counter;
-        handle->nmi     = nmi;
-        handle->sample  = sample;
-
-        if (!data->nr_pages)
-                goto fail;
-
-        have_lost = atomic_read(&data->lost);
-        if (have_lost)
-                size += sizeof(lost_event);
-
-        perf_output_lock(handle);
-
-        do {
-                offset = head = atomic_long_read(&data->head);
-                head += size;
-                if (unlikely(!perf_output_space(data, offset, head)))
-                        goto fail;
-        } while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
-
-        handle->offset  = offset;
-        handle->head    = head;
-
-        if ((offset >> PAGE_SHIFT) != (head >> PAGE_SHIFT))
-                atomic_set(&data->wakeup, 1);
-
-        if (have_lost) {
-                lost_event.header.type = PERF_EVENT_LOST;
-                lost_event.header.misc = 0;
-                lost_event.header.size = sizeof(lost_event);
-                lost_event.id          = counter->id;
-                lost_event.lost        = atomic_xchg(&data->lost, 0);
-
-                perf_output_put(handle, lost_event);
-        }
-
-        return 0;
-
-fail:
-        atomic_inc(&data->lost);
-        perf_output_unlock(handle);
-out:
-        rcu_read_unlock();
-
-        return -ENOSPC;
-}
-
-static void perf_output_end(struct perf_output_handle *handle)
-{
-        struct perf_counter *counter = handle->counter;
-        struct perf_mmap_data *data = handle->data;
-
-        int wakeup_events = counter->attr.wakeup_events;
-
-        if (handle->sample && wakeup_events) {
-                int events = atomic_inc_return(&data->events);
-                if (events >= wakeup_events) {
-                        atomic_sub(wakeup_events, &data->events);
-                        atomic_set(&data->wakeup, 1);
-                }
-        }
-
-        perf_output_unlock(handle);
-        rcu_read_unlock();
-}
-
-static u32 perf_counter_pid(struct perf_counter *counter, struct task_struct *p)
-{
-        /*
-         * only top level counters have the pid namespace they were created in
-         */
-        if (counter->parent)
-                counter = counter->parent;
-
-        return task_tgid_nr_ns(p, counter->ns);
-}
-
-static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p)
-{
-        /*
-         * only top level counters have the pid namespace they were created in
-         */
-        if (counter->parent)
-                counter = counter->parent;
-
-        return task_pid_nr_ns(p, counter->ns);
-}
-
-static void perf_output_read_one(struct perf_output_handle *handle,
-                                 struct perf_counter *counter)
-{
-        u64 read_format = counter->attr.read_format;
-        u64 values[4];
-        int n = 0;
-
-        values[n++] = atomic64_read(&counter->count);
-        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-                values[n++] = counter->total_time_enabled +
-                        atomic64_read(&counter->child_total_time_enabled);
-        }
-        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-                values[n++] = counter->total_time_running +
-                        atomic64_read(&counter->child_total_time_running);
-        }
-        if (read_format & PERF_FORMAT_ID)
-                values[n++] = primary_counter_id(counter);
-
-        perf_output_copy(handle, values, n * sizeof(u64));
-}
-
-/*
- * XXX PERF_FORMAT_GROUP vs inherited counters seems difficult.
- */
-static void perf_output_read_group(struct perf_output_handle *handle,
-                            struct perf_counter *counter)
-{
-        struct perf_counter *leader = counter->group_leader, *sub;
-        u64 read_format = counter->attr.read_format;
-        u64 values[5];
-        int n = 0;
-
-        values[n++] = 1 + leader->nr_siblings;
-
-        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
-                values[n++] = leader->total_time_enabled;
-
-        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
-                values[n++] = leader->total_time_running;
-
-        if (leader != counter)
-                leader->pmu->read(leader);
-
-        values[n++] = atomic64_read(&leader->count);
-        if (read_format & PERF_FORMAT_ID)
-                values[n++] = primary_counter_id(leader);
-
-        perf_output_copy(handle, values, n * sizeof(u64));
-
-        list_for_each_entry(sub, &leader->sibling_list, list_entry) {
-                n = 0;
-
-                if (sub != counter)
-                        sub->pmu->read(sub);
-
-                values[n++] = atomic64_read(&sub->count);
-                if (read_format & PERF_FORMAT_ID)
-                        values[n++] = primary_counter_id(sub);
-
-                perf_output_copy(handle, values, n * sizeof(u64));
-        }
-}
-
-static void perf_output_read(struct perf_output_handle *handle,
-                             struct perf_counter *counter)
-{
-        if (counter->attr.read_format & PERF_FORMAT_GROUP)
-                perf_output_read_group(handle, counter);
-        else
-                perf_output_read_one(handle, counter);
-}
-
-void perf_counter_output(struct perf_counter *counter, int nmi,
-                                struct perf_sample_data *data)
-{
-        int ret;
-        u64 sample_type = counter->attr.sample_type;
-        struct perf_output_handle handle;
-        struct perf_event_header header;
-        u64 ip;
-        struct {
-                u32 pid, tid;
-        } tid_entry;
-        struct perf_callchain_entry *callchain = NULL;
-        int callchain_size = 0;
-        u64 time;
-        struct {
-                u32 cpu, reserved;
-        } cpu_entry;
-
-        header.type = PERF_EVENT_SAMPLE;
-        header.size = sizeof(header);
-
-        header.misc = 0;
-        header.misc |= perf_misc_flags(data->regs);
-
-        if (sample_type & PERF_SAMPLE_IP) {
-                ip = perf_instruction_pointer(data->regs);
-                header.size += sizeof(ip);
-        }
-
-        if (sample_type & PERF_SAMPLE_TID) {
-                /* namespace issues */
-                tid_entry.pid = perf_counter_pid(counter, current);
-                tid_entry.tid = perf_counter_tid(counter, current);
-
-                header.size += sizeof(tid_entry);
-        }
-
-        if (sample_type & PERF_SAMPLE_TIME) {
-                /*
-                 * Maybe do better on x86 and provide cpu_clock_nmi()
-                 */
-                time = sched_clock();
-
-                header.size += sizeof(u64);
-        }
-
-        if (sample_type & PERF_SAMPLE_ADDR)
-                header.size += sizeof(u64);
-
-        if (sample_type & PERF_SAMPLE_ID)
-                header.size += sizeof(u64);
-
-        if (sample_type & PERF_SAMPLE_STREAM_ID)
-                header.size += sizeof(u64);
-
-        if (sample_type & PERF_SAMPLE_CPU) {
-                header.size += sizeof(cpu_entry);
-
-                cpu_entry.cpu = raw_smp_processor_id();
-                cpu_entry.reserved = 0;
-        }
-
-        if (sample_type & PERF_SAMPLE_PERIOD)
-                header.size += sizeof(u64);
-
-        if (sample_type & PERF_SAMPLE_READ)
-                header.size += perf_counter_read_size(counter);
-
-        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
-                callchain = perf_callchain(data->regs);
-
-                if (callchain) {
-                        callchain_size = (1 + callchain->nr) * sizeof(u64);
-                        header.size += callchain_size;
-                } else
-                        header.size += sizeof(u64);
-        }
-
-        if (sample_type & PERF_SAMPLE_RAW) {
-                int size = sizeof(u32);
-
-                if (data->raw)
-                        size += data->raw->size;
-                else
-                        size += sizeof(u32);
-
-                WARN_ON_ONCE(size & (sizeof(u64)-1));
-                header.size += size;
-        }
-
-        ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
-        if (ret)
-                return;
-
-        perf_output_put(&handle, header);
-
-        if (sample_type & PERF_SAMPLE_IP)
-                perf_output_put(&handle, ip);
-
-        if (sample_type & PERF_SAMPLE_TID)
-                perf_output_put(&handle, tid_entry);
-
-        if (sample_type & PERF_SAMPLE_TIME)
-                perf_output_put(&handle, time);
-
-        if (sample_type & PERF_SAMPLE_ADDR)
-                perf_output_put(&handle, data->addr);
-
-        if (sample_type & PERF_SAMPLE_ID) {
-                u64 id = primary_counter_id(counter);
-
-                perf_output_put(&handle, id);
-        }
-
-        if (sample_type & PERF_SAMPLE_STREAM_ID)
-                perf_output_put(&handle, counter->id);
-
-        if (sample_type & PERF_SAMPLE_CPU)
-                perf_output_put(&handle, cpu_entry);
-
-        if (sample_type & PERF_SAMPLE_PERIOD)
-                perf_output_put(&handle, data->period);
-
-        if (sample_type & PERF_SAMPLE_READ)
-                perf_output_read(&handle, counter);
-
-        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
-                if (callchain)
-                        perf_output_copy(&handle, callchain, callchain_size);
-                else {
-                        u64 nr = 0;
-                        perf_output_put(&handle, nr);
-                }
-        }
-
-        if (sample_type & PERF_SAMPLE_RAW) {
-                if (data->raw) {
-                        perf_output_put(&handle, data->raw->size);
-                        perf_output_copy(&handle, data->raw->data, data->raw->size);
-                } else {
-                        struct {
-                                u32     size;
-                                u32     data;
-                        } raw = {
-                                .size = sizeof(u32),
-                                .data = 0,
-                        };
-                        perf_output_put(&handle, raw);
-                }
-        }
-
-        perf_output_end(&handle);
-}
-
-/*
- * read event
- */
-
-struct perf_read_event {
-        struct perf_event_header        header;
-
-        u32                             pid;
-        u32                             tid;
-};
-
-static void
-perf_counter_read_event(struct perf_counter *counter,
-                        struct task_struct *task)
-{
-        struct perf_output_handle handle;
-        struct perf_read_event event = {
-                .header = {
-                        .type = PERF_EVENT_READ,
-                        .misc = 0,
-                        .size = sizeof(event) + perf_counter_read_size(counter),
-                },
-                .pid = perf_counter_pid(counter, task),
-                .tid = perf_counter_tid(counter, task),
-        };
-        int ret;
-
-        ret = perf_output_begin(&handle, counter, event.header.size, 0, 0);
-        if (ret)
-                return;
-
-        perf_output_put(&handle, event);
-        perf_output_read(&handle, counter);
-
-        perf_output_end(&handle);
-}
-
-/*
- * task tracking -- fork/exit
- *
- * enabled by: attr.comm | attr.mmap | attr.task
- */
-
-struct perf_task_event {
-        struct task_struct              *task;
-        struct perf_counter_context     *task_ctx;
-
-        struct {
-                struct perf_event_header        header;
-
-                u32                             pid;
-                u32                             ppid;
-                u32                             tid;
-                u32                             ptid;
-        } event;
-};
-
-static void perf_counter_task_output(struct perf_counter *counter,
-                                     struct perf_task_event *task_event)
-{
-        struct perf_output_handle handle;
-        int size = task_event->event.header.size;
-        struct task_struct *task = task_event->task;
-        int ret = perf_output_begin(&handle, counter, size, 0, 0);
-
-        if (ret)
-                return;
-
-        task_event->event.pid = perf_counter_pid(counter, task);
-        task_event->event.ppid = perf_counter_pid(counter, current);
-
-        task_event->event.tid = perf_counter_tid(counter, task);
-        task_event->event.ptid = perf_counter_tid(counter, current);
-
-        perf_output_put(&handle, task_event->event);
-        perf_output_end(&handle);
-}
-
-static int perf_counter_task_match(struct perf_counter *counter)
-{
-        if (counter->attr.comm || counter->attr.mmap || counter->attr.task)
-                return 1;
-
-        return 0;
-}
-
-static void perf_counter_task_ctx(struct perf_counter_context *ctx,
-                                  struct perf_task_event *task_event)
-{
-        struct perf_counter *counter;
-
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
-        list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-                if (perf_counter_task_match(counter))
-                        perf_counter_task_output(counter, task_event);
-        }
-        rcu_read_unlock();
-}
-
-static void perf_counter_task_event(struct perf_task_event *task_event)
-{
-        struct perf_cpu_context *cpuctx;
-        struct perf_counter_context *ctx = task_event->task_ctx;
-
-        cpuctx = &get_cpu_var(perf_cpu_context);
-        perf_counter_task_ctx(&cpuctx->ctx, task_event);
-        put_cpu_var(perf_cpu_context);
-
-        rcu_read_lock();
-        if (!ctx)
-                ctx = rcu_dereference(task_event->task->perf_counter_ctxp);
-        if (ctx)
-                perf_counter_task_ctx(ctx, task_event);
-        rcu_read_unlock();
-}
-
-static void perf_counter_task(struct task_struct *task,
-                              struct perf_counter_context *task_ctx,
-                              int new)
-{
-        struct perf_task_event task_event;
-
-        if (!atomic_read(&nr_comm_counters) &&
-            !atomic_read(&nr_mmap_counters) &&
-            !atomic_read(&nr_task_counters))
-                return;
-
-        task_event = (struct perf_task_event){
-                .task     = task,
-                .task_ctx = task_ctx,
-                .event    = {
-                        .header = {
-                                .type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
-                                .misc = 0,
-                                .size = sizeof(task_event.event),
-                        },
-                        /* .pid  */
-                        /* .ppid */
-                        /* .tid  */
-                        /* .ptid */
-                },
-        };
-
-        perf_counter_task_event(&task_event);
-}
-
-void perf_counter_fork(struct task_struct *task)
-{
-        perf_counter_task(task, NULL, 1);
-}
-
-/*
- * comm tracking
- */
-
-struct perf_comm_event {
-        struct task_struct      *task;
-        char                    *comm;
-        int                     comm_size;
-
-        struct {
-                struct perf_event_header        header;
-
-                u32                             pid;
-                u32                             tid;
-        } event;
-};
-
-static void perf_counter_comm_output(struct perf_counter *counter,
-                                     struct perf_comm_event *comm_event)
-{
-        struct perf_output_handle handle;
-        int size = comm_event->event.header.size;
-        int ret = perf_output_begin(&handle, counter, size, 0, 0);
-
-        if (ret)
-                return;
-
-        comm_event->event.pid = perf_counter_pid(counter, comm_event->task);
-        comm_event->event.tid = perf_counter_tid(counter, comm_event->task);
-
-        perf_output_put(&handle, comm_event->event);
-        perf_output_copy(&handle, comm_event->comm,
-                                   comm_event->comm_size);
-        perf_output_end(&handle);
-}
-
-static int perf_counter_comm_match(struct perf_counter *counter)
-{
-        if (counter->attr.comm)
-                return 1;
-
-        return 0;
-}
-
-static void perf_counter_comm_ctx(struct perf_counter_context *ctx,
-                                  struct perf_comm_event *comm_event)
-{
-        struct perf_counter *counter;
-
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
-        list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-                if (perf_counter_comm_match(counter))
-                        perf_counter_comm_output(counter, comm_event);
-        }
-        rcu_read_unlock();
-}
-
-static void perf_counter_comm_event(struct perf_comm_event *comm_event)
-{
-        struct perf_cpu_context *cpuctx;
-        struct perf_counter_context *ctx;
-        unsigned int size;
-        char comm[TASK_COMM_LEN];
-
-        memset(comm, 0, sizeof(comm));
-        strncpy(comm, comm_event->task->comm, sizeof(comm));
-        size = ALIGN(strlen(comm)+1, sizeof(u64));
-
-        comm_event->comm = comm;
-        comm_event->comm_size = size;
-
-        comm_event->event.header.size = sizeof(comm_event->event) + size;
-
-        cpuctx = &get_cpu_var(perf_cpu_context);
-        perf_counter_comm_ctx(&cpuctx->ctx, comm_event);
-        put_cpu_var(perf_cpu_context);
-
-        rcu_read_lock();
-        /*
-         * doesn't really matter which of the child contexts the
-         * events ends up in.
-         */
-        ctx = rcu_dereference(current->perf_counter_ctxp);
-        if (ctx)
-                perf_counter_comm_ctx(ctx, comm_event);
-        rcu_read_unlock();
-}
-
-void perf_counter_comm(struct task_struct *task)
-{
-        struct perf_comm_event comm_event;
-
-        if (task->perf_counter_ctxp)
-                perf_counter_enable_on_exec(task);
-
-        if (!atomic_read(&nr_comm_counters))
-                return;
-
-        comm_event = (struct perf_comm_event){
-                .task   = task,
-                /* .comm      */
-                /* .comm_size */
-                .event  = {
-                        .header = {
-                                .type = PERF_EVENT_COMM,
-                                .misc = 0,
-                                /* .size */
-                        },
-                        /* .pid */
-                        /* .tid */
-                },
-        };
-
-        perf_counter_comm_event(&comm_event);
-}
-
-/*
- * mmap tracking
- */
-
-struct perf_mmap_event {
-        struct vm_area_struct   *vma;
-
-        const char              *file_name;
-        int                     file_size;
-
-        struct {
-                struct perf_event_header        header;
-
-                u32                             pid;
-                u32                             tid;
-                u64                             start;
-                u64                             len;
-                u64                             pgoff;
-        } event;
-};
-
-static void perf_counter_mmap_output(struct perf_counter *counter,
-                                     struct perf_mmap_event *mmap_event)
-{
-        struct perf_output_handle handle;
-        int size = mmap_event->event.header.size;
-        int ret = perf_output_begin(&handle, counter, size, 0, 0);
-
-        if (ret)
-                return;
-
-        mmap_event->event.pid = perf_counter_pid(counter, current);
-        mmap_event->event.tid = perf_counter_tid(counter, current);
-
-        perf_output_put(&handle, mmap_event->event);
-        perf_output_copy(&handle, mmap_event->file_name,
-                                   mmap_event->file_size);
-        perf_output_end(&handle);
-}
-
-static int perf_counter_mmap_match(struct perf_counter *counter,
-                                   struct perf_mmap_event *mmap_event)
-{
-        if (counter->attr.mmap)
-                return 1;
-
-        return 0;
-}
-
-static void perf_counter_mmap_ctx(struct perf_counter_context *ctx,
-                                  struct perf_mmap_event *mmap_event)
-{
-        struct perf_counter *counter;
-
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
-        list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-                if (perf_counter_mmap_match(counter, mmap_event))
-                        perf_counter_mmap_output(counter, mmap_event);
-        }
-        rcu_read_unlock();
-}
-
-static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
-{
-        struct perf_cpu_context *cpuctx;
-        struct perf_counter_context *ctx;
-        struct vm_area_struct *vma = mmap_event->vma;
-        struct file *file = vma->vm_file;
-        unsigned int size;
-        char tmp[16];
-        char *buf = NULL;
-        const char *name;
-
-        memset(tmp, 0, sizeof(tmp));
-
-        if (file) {
-                /*
-                 * d_path works from the end of the buffer backwards, so we
-                 * need to add enough zero bytes after the string to handle
-                 * the 64bit alignment we do later.
-                 */
-                buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
-                if (!buf) {
-                        name = strncpy(tmp, "//enomem", sizeof(tmp));
-                        goto got_name;
-                }
-                name = d_path(&file->f_path, buf, PATH_MAX);
-                if (IS_ERR(name)) {
-                        name = strncpy(tmp, "//toolong", sizeof(tmp));
-                        goto got_name;
-                }
-        } else {
-                if (arch_vma_name(mmap_event->vma)) {
-                        name = strncpy(tmp, arch_vma_name(mmap_event->vma),
-                                       sizeof(tmp));
-                        goto got_name;
-                }
-
-                if (!vma->vm_mm) {
-                        name = strncpy(tmp, "[vdso]", sizeof(tmp));
-                        goto got_name;
-                }
-
-                name = strncpy(tmp, "//anon", sizeof(tmp));
-                goto got_name;
-        }
-
-got_name:
-        size = ALIGN(strlen(name)+1, sizeof(u64));
-
-        mmap_event->file_name = name;
-        mmap_event->file_size = size;
-
-        mmap_event->event.header.size = sizeof(mmap_event->event) + size;
-
-        cpuctx = &get_cpu_var(perf_cpu_context);
-        perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event);
-        put_cpu_var(perf_cpu_context);
-
-        rcu_read_lock();
-        /*
-         * doesn't really matter which of the child contexts the
-         * events ends up in.
-         */
-        ctx = rcu_dereference(current->perf_counter_ctxp);
-        if (ctx)
-                perf_counter_mmap_ctx(ctx, mmap_event);
-        rcu_read_unlock();
-
-        kfree(buf);
-}
-
-void __perf_counter_mmap(struct vm_area_struct *vma)
-{
-        struct perf_mmap_event mmap_event;
-
-        if (!atomic_read(&nr_mmap_counters))
-                return;
-
-        mmap_event = (struct perf_mmap_event){
-                .vma    = vma,
-                /* .file_name */
-                /* .file_size */
-                .event  = {
-                        .header = {
-                                .type = PERF_EVENT_MMAP,
-                                .misc = 0,
-                                /* .size */
-                        },
-                        /* .pid */
-                        /* .tid */
-                        .start  = vma->vm_start,
-                        .len    = vma->vm_end - vma->vm_start,
-                        .pgoff  = vma->vm_pgoff,
-                },
-        };
-
-        perf_counter_mmap_event(&mmap_event);
-}
-
-/*
- * IRQ throttle logging
- */
-
-static void perf_log_throttle(struct perf_counter *counter, int enable)
-{
-        struct perf_output_handle handle;
-        int ret;
-
-        struct {
-                struct perf_event_header        header;
-                u64                             time;
-                u64                             id;
-                u64                             stream_id;
-        } throttle_event = {
-                .header = {
-                        .type = PERF_EVENT_THROTTLE,
-                        .misc = 0,
-                        .size = sizeof(throttle_event),
-                },
-                .time           = sched_clock(),
-                .id             = primary_counter_id(counter),
-                .stream_id      = counter->id,
-        };
-
-        if (enable)
-                throttle_event.header.type = PERF_EVENT_UNTHROTTLE;
-
-        ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0);
-        if (ret)
-                return;
-
-        perf_output_put(&handle, throttle_event);
-        perf_output_end(&handle);
-}
-
-/*
- * Generic counter overflow handling, sampling.
- */
-
-int perf_counter_overflow(struct perf_counter *counter, int nmi,
-                          struct perf_sample_data *data)
-{
-        int events = atomic_read(&counter->event_limit);
-        int throttle = counter->pmu->unthrottle != NULL;
-        struct hw_perf_counter *hwc = &counter->hw;
-        int ret = 0;
-
-        if (!throttle) {
-                hwc->interrupts++;
-        } else {
-                if (hwc->interrupts != MAX_INTERRUPTS) {
-                        hwc->interrupts++;
-                        if (HZ * hwc->interrupts >
-                                        (u64)sysctl_perf_counter_sample_rate) {
-                                hwc->interrupts = MAX_INTERRUPTS;
-                                perf_log_throttle(counter, 0);
-                                ret = 1;
-                        }
-                } else {
-                        /*
-                         * Keep re-disabling counters even though on the previous
-                         * pass we disabled it - just in case we raced with a
-                         * sched-in and the counter got enabled again:
-                         */
-                        ret = 1;
-                }
-        }
-
-        if (counter->attr.freq) {
-                u64 now = sched_clock();
-                s64 delta = now - hwc->freq_stamp;
-
-                hwc->freq_stamp = now;
-
-                if (delta > 0 && delta < TICK_NSEC)
-                        perf_adjust_period(counter, NSEC_PER_SEC / (int)delta);
-        }
-
-        /*
-         * XXX event_limit might not quite work as expected on inherited
-         * counters
-         */
-
-        counter->pending_kill = POLL_IN;
-        if (events && atomic_dec_and_test(&counter->event_limit)) {
-                ret = 1;
-                counter->pending_kill = POLL_HUP;
-                if (nmi) {
-                        counter->pending_disable = 1;
-                        perf_pending_queue(&counter->pending,
-                                           perf_pending_counter);
-                } else
-                        perf_counter_disable(counter);
-        }
-
-        perf_counter_output(counter, nmi, data);
-        return ret;
-}
-
-/*
- * Generic software counter infrastructure
- */
-
-/*
- * We directly increment counter->count and keep a second value in
- * counter->hw.period_left to count intervals. This period counter
- * is kept in the range [-sample_period, 0] so that we can use the
- * sign as trigger.
- */
-
-static u64 perf_swcounter_set_period(struct perf_counter *counter)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-        u64 period = hwc->last_period;
-        u64 nr, offset;
-        s64 old, val;
-
-        hwc->last_period = hwc->sample_period;
-
-again:
-        old = val = atomic64_read(&hwc->period_left);
-        if (val < 0)
-                return 0;
-
-        nr = div64_u64(period + val, period);
-        offset = nr * period;
-        val -= offset;
-        if (atomic64_cmpxchg(&hwc->period_left, old, val) != old)
-                goto again;
-
-        return nr;
-}
-
-static void perf_swcounter_overflow(struct perf_counter *counter,
-                                    int nmi, struct perf_sample_data *data)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-        u64 overflow;
-
-        data->period = counter->hw.last_period;
-        overflow = perf_swcounter_set_period(counter);
-
-        if (hwc->interrupts == MAX_INTERRUPTS)
-                return;
-
-        for (; overflow; overflow--) {
-                if (perf_counter_overflow(counter, nmi, data)) {
-                        /*
-                         * We inhibit the overflow from happening when
-                         * hwc->interrupts == MAX_INTERRUPTS.
-                         */
-                        break;
-                }
-        }
-}
-
-static void perf_swcounter_unthrottle(struct perf_counter *counter)
-{
-        /*
-         * Nothing to do, we already reset hwc->interrupts.
-         */
-}
-
-static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
-                               int nmi, struct perf_sample_data *data)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-
-        atomic64_add(nr, &counter->count);
-
-        if (!hwc->sample_period)
-                return;
-
-        if (!data->regs)
-                return;
-
-        if (!atomic64_add_negative(nr, &hwc->period_left))
-                perf_swcounter_overflow(counter, nmi, data);
-}
-
-static int perf_swcounter_is_counting(struct perf_counter *counter)
-{
-        /*
-         * The counter is active, we're good!
-         */
-        if (counter->state == PERF_COUNTER_STATE_ACTIVE)
-                return 1;
-
-        /*
-         * The counter is off/error, not counting.
-         */
-        if (counter->state != PERF_COUNTER_STATE_INACTIVE)
-                return 0;
-
-        /*
-         * The counter is inactive, if the context is active
-         * we're part of a group that didn't make it on the 'pmu',
-         * not counting.
-         */
-        if (counter->ctx->is_active)
-                return 0;
-
-        /*
-         * We're inactive and the context is too, this means the
-         * task is scheduled out, we're counting events that happen
-         * to us, like migration events.
-         */
-        return 1;
-}
-
-static int perf_swcounter_match(struct perf_counter *counter,
-                                enum perf_type_id type,
-                                u32 event, struct pt_regs *regs)
-{
-        if (!perf_swcounter_is_counting(counter))
-                return 0;
-
-        if (counter->attr.type != type)
-                return 0;
-        if (counter->attr.config != event)
-                return 0;
-
-        if (regs) {
-                if (counter->attr.exclude_user && user_mode(regs))
-                        return 0;
-
-                if (counter->attr.exclude_kernel && !user_mode(regs))
-                        return 0;
-        }
-
-        return 1;
-}
-
-static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
-                                     enum perf_type_id type,
-                                     u32 event, u64 nr, int nmi,
-                                     struct perf_sample_data *data)
-{
-        struct perf_counter *counter;
-
-        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-                return;
-
-        rcu_read_lock();
-        list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-                if (perf_swcounter_match(counter, type, event, data->regs))
-                        perf_swcounter_add(counter, nr, nmi, data);
-        }
-        rcu_read_unlock();
-}
-
-static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx)
-{
-        if (in_nmi())
-                return &cpuctx->recursion[3];
-
-        if (in_irq())
-                return &cpuctx->recursion[2];
-
-        if (in_softirq())
-                return &cpuctx->recursion[1];
-
-        return &cpuctx->recursion[0];
-}
-
-static void do_perf_swcounter_event(enum perf_type_id type, u32 event,
-                                    u64 nr, int nmi,
-                                    struct perf_sample_data *data)
-{
-        struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
-        int *recursion = perf_swcounter_recursion_context(cpuctx);
-        struct perf_counter_context *ctx;
-
-        if (*recursion)
-                goto out;
-
-        (*recursion)++;
-        barrier();
-
-        perf_swcounter_ctx_event(&cpuctx->ctx, type, event,
-                                 nr, nmi, data);
-        rcu_read_lock();
-        /*
-         * doesn't really matter which of the child contexts the
-         * events ends up in.
-         */
-        ctx = rcu_dereference(current->perf_counter_ctxp);
-        if (ctx)
-                perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data);
-        rcu_read_unlock();
-
-        barrier();
-        (*recursion)--;
-
-out:
-        put_cpu_var(perf_cpu_context);
-}
-
-void __perf_swcounter_event(u32 event, u64 nr, int nmi,
-                            struct pt_regs *regs, u64 addr)
-{
-        struct perf_sample_data data = {
-                .regs = regs,
-                .addr = addr,
-        };
-
-        do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, &data);
-}
-
-static void perf_swcounter_read(struct perf_counter *counter)
-{
-}
-
-static int perf_swcounter_enable(struct perf_counter *counter)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-
-        if (hwc->sample_period) {
-                hwc->last_period = hwc->sample_period;
-                perf_swcounter_set_period(counter);
-        }
-        return 0;
-}
-
-static void perf_swcounter_disable(struct perf_counter *counter)
-{
-}
-
-static const struct pmu perf_ops_generic = {
-        .enable         = perf_swcounter_enable,
-        .disable        = perf_swcounter_disable,
-        .read           = perf_swcounter_read,
-        .unthrottle     = perf_swcounter_unthrottle,
-};
-
-/*
- * hrtimer based swcounter callback
- */
-
-static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
-{
-        enum hrtimer_restart ret = HRTIMER_RESTART;
-        struct perf_sample_data data;
-        struct perf_counter *counter;
-        u64 period;
-
-        counter = container_of(hrtimer, struct perf_counter, hw.hrtimer);
-        counter->pmu->read(counter);
-
-        data.addr = 0;
-        data.regs = get_irq_regs();
-        /*
-         * In case we exclude kernel IPs or are somehow not in interrupt
-         * context, provide the next best thing, the user IP.
-         */
-        if ((counter->attr.exclude_kernel || !data.regs) &&
-                        !counter->attr.exclude_user)
-                data.regs = task_pt_regs(current);
-
-        if (data.regs) {
-                if (perf_counter_overflow(counter, 0, &data))
-                        ret = HRTIMER_NORESTART;
-        }
-
-        period = max_t(u64, 10000, counter->hw.sample_period);
-        hrtimer_forward_now(hrtimer, ns_to_ktime(period));
-
-        return ret;
-}
-
-/*
- * Software counter: cpu wall time clock
- */
-
-static void cpu_clock_perf_counter_update(struct perf_counter *counter)
-{
-        int cpu = raw_smp_processor_id();
-        s64 prev;
-        u64 now;
-
-        now = cpu_clock(cpu);
-        prev = atomic64_read(&counter->hw.prev_count);
-        atomic64_set(&counter->hw.prev_count, now);
-        atomic64_add(now - prev, &counter->count);
-}
-
-static int cpu_clock_perf_counter_enable(struct perf_counter *counter)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-        int cpu = raw_smp_processor_id();
-
-        atomic64_set(&hwc->prev_count, cpu_clock(cpu));
-        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-        hwc->hrtimer.function = perf_swcounter_hrtimer;
-        if (hwc->sample_period) {
-                u64 period = max_t(u64, 10000, hwc->sample_period);
-                __hrtimer_start_range_ns(&hwc->hrtimer,
-                                ns_to_ktime(period), 0,
-                                HRTIMER_MODE_REL, 0);
-        }
-
-        return 0;
-}
-
-static void cpu_clock_perf_counter_disable(struct perf_counter *counter)
-{
-        if (counter->hw.sample_period)
-                hrtimer_cancel(&counter->hw.hrtimer);
-        cpu_clock_perf_counter_update(counter);
-}
-
-static void cpu_clock_perf_counter_read(struct perf_counter *counter)
-{
-        cpu_clock_perf_counter_update(counter);
-}
-
-static const struct pmu perf_ops_cpu_clock = {
-        .enable         = cpu_clock_perf_counter_enable,
-        .disable        = cpu_clock_perf_counter_disable,
-        .read           = cpu_clock_perf_counter_read,
-};
-
-/*
- * Software counter: task time clock
- */
-
-static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now)
-{
-        u64 prev;
-        s64 delta;
-
-        prev = atomic64_xchg(&counter->hw.prev_count, now);
-        delta = now - prev;
-        atomic64_add(delta, &counter->count);
-}
-
-static int task_clock_perf_counter_enable(struct perf_counter *counter)
-{
-        struct hw_perf_counter *hwc = &counter->hw;
-        u64 now;
-
-        now = counter->ctx->time;
-
-        atomic64_set(&hwc->prev_count, now);
-        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-        hwc->hrtimer.function = perf_swcounter_hrtimer;
-        if (hwc->sample_period) {
-                u64 period = max_t(u64, 10000, hwc->sample_period);
-                __hrtimer_start_range_ns(&hwc->hrtimer,
-                                ns_to_ktime(period), 0,
-                                HRTIMER_MODE_REL, 0);
-        }
-
-        return 0;
-}
-
-static void task_clock_perf_counter_disable(struct perf_counter *counter)
-{
-        if (counter->hw.sample_period)
-                hrtimer_cancel(&counter->hw.hrtimer);
-        task_clock_perf_counter_update(counter, counter->ctx->time);
-
-}
-
-static void task_clock_perf_counter_read(struct perf_counter *counter)
-{
-        u64 time;
-
-        if (!in_nmi()) {
-                update_context_time(counter->ctx);
-                time = counter->ctx->time;
-        } else {
-                u64 now = perf_clock();
-                u64 delta = now - counter->ctx->timestamp;
-                time = counter->ctx->time + delta;
-        }
-
-        task_clock_perf_counter_update(counter, time);
-}
-
-static const struct pmu perf_ops_task_clock = {
-        .enable         = task_clock_perf_counter_enable,
-        .disable        = task_clock_perf_counter_disable,
-        .read           = task_clock_perf_counter_read,
-};
-
-#ifdef CONFIG_EVENT_PROFILE
-void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record,
-                          int entry_size)
-{
-        struct perf_raw_record raw = {
-                .size = entry_size,
-                .data = record,
-        };
-
-        struct perf_sample_data data = {
-                .regs = get_irq_regs(),
-                .addr = addr,
-                .raw = &raw,
-        };
-
-        if (!data.regs)
-                data.regs = task_pt_regs(current);
-
-        do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, &data);
-}
-EXPORT_SYMBOL_GPL(perf_tpcounter_event);
-
-extern int ftrace_profile_enable(int);
-extern void ftrace_profile_disable(int);
-
-static void tp_perf_counter_destroy(struct perf_counter *counter)
-{
-        ftrace_profile_disable(counter->attr.config);
-}
-
-static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
-{
-        /*
-         * Raw tracepoint data is a severe data leak, only allow root to
-         * have these.
-         */
-        if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
-                        perf_paranoid_tracepoint_raw() &&
-                        !capable(CAP_SYS_ADMIN))
-                return ERR_PTR(-EPERM);
-
-        if (ftrace_profile_enable(counter->attr.config))
-                return NULL;
-
-        counter->destroy = tp_perf_counter_destroy;
-
-        return &perf_ops_generic;
-}
-#else
-static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
-{
-        return NULL;
-}
-#endif
-
-atomic_t perf_swcounter_enabled[PERF_COUNT_SW_MAX];
-
-static void sw_perf_counter_destroy(struct perf_counter *counter)
-{
-        u64 event = counter->attr.config;
-
-        WARN_ON(counter->parent);
-
-        atomic_dec(&perf_swcounter_enabled[event]);
-}
-
-static const struct pmu *sw_perf_counter_init(struct perf_counter *counter)
-{
-        const struct pmu *pmu = NULL;
-        u64 event = counter->attr.config;
-
-        /*
-         * Software counters (currently) can't in general distinguish
-         * between user, kernel and hypervisor events.
-         * However, context switches and cpu migrations are considered
-         * to be kernel events, and page faults are never hypervisor
-         * events.
-         */
-        switch (event) {
-        case PERF_COUNT_SW_CPU_CLOCK:
-                pmu = &perf_ops_cpu_clock;
-
-                break;
-        case PERF_COUNT_SW_TASK_CLOCK:
-                /*
-                 * If the user instantiates this as a per-cpu counter,
-                 * use the cpu_clock counter instead.
-                 */
-                if (counter->ctx->task)
-                        pmu = &perf_ops_task_clock;
-                else
-                        pmu = &perf_ops_cpu_clock;
-
-                break;
-        case PERF_COUNT_SW_PAGE_FAULTS:
-        case PERF_COUNT_SW_PAGE_FAULTS_MIN:
-        case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
-        case PERF_COUNT_SW_CONTEXT_SWITCHES:
-        case PERF_COUNT_SW_CPU_MIGRATIONS:
-                if (!counter->parent) {
-                        atomic_inc(&perf_swcounter_enabled[event]);
-                        counter->destroy = sw_perf_counter_destroy;
-                }
-                pmu = &perf_ops_generic;
-                break;
-        }
-
-        return pmu;
-}
-
-/*
- * Allocate and initialize a counter structure
- */
-static struct perf_counter *
-perf_counter_alloc(struct perf_counter_attr *attr,
-                   int cpu,
-                   struct perf_counter_context *ctx,
-                   struct perf_counter *group_leader,
-                   struct perf_counter *parent_counter,
-                   gfp_t gfpflags)
-{
-        const struct pmu *pmu;
-        struct perf_counter *counter;
-        struct hw_perf_counter *hwc;
-        long err;
-
-        counter = kzalloc(sizeof(*counter), gfpflags);
-        if (!counter)
-                return ERR_PTR(-ENOMEM);
-
-        /*
-         * Single counters are their own group leaders, with an
-         * empty sibling list:
-         */
-        if (!group_leader)
-                group_leader = counter;
-
-        mutex_init(&counter->child_mutex);
-        INIT_LIST_HEAD(&counter->child_list);
-
-        INIT_LIST_HEAD(&counter->list_entry);
-        INIT_LIST_HEAD(&counter->event_entry);
-        INIT_LIST_HEAD(&counter->sibling_list);
-        init_waitqueue_head(&counter->waitq);
-
-        mutex_init(&counter->mmap_mutex);
-
-        counter->cpu            = cpu;
-        counter->attr           = *attr;
-        counter->group_leader   = group_leader;
-        counter->pmu            = NULL;
-        counter->ctx            = ctx;
-        counter->oncpu          = -1;
-
-        counter->parent         = parent_counter;
-
-        counter->ns             = get_pid_ns(current->nsproxy->pid_ns);
-        counter->id             = atomic64_inc_return(&perf_counter_id);
-
-        counter->state          = PERF_COUNTER_STATE_INACTIVE;
-
-        if (attr->disabled)
-                counter->state = PERF_COUNTER_STATE_OFF;
-
-        pmu = NULL;
-
-        hwc = &counter->hw;
-        hwc->sample_period = attr->sample_period;
-        if (attr->freq && attr->sample_freq)
-                hwc->sample_period = 1;
-        hwc->last_period = hwc->sample_period;
-
-        atomic64_set(&hwc->period_left, hwc->sample_period);
-
-        /*
-         * we currently do not support PERF_FORMAT_GROUP on inherited counters
-         */
-        if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
-                goto done;
-
-        switch (attr->type) {
-        case PERF_TYPE_RAW:
-        case PERF_TYPE_HARDWARE:
-        case PERF_TYPE_HW_CACHE:
-                pmu = hw_perf_counter_init(counter);
-                break;
-
-        case PERF_TYPE_SOFTWARE:
-                pmu = sw_perf_counter_init(counter);
-                break;
-
-        case PERF_TYPE_TRACEPOINT:
-                pmu = tp_perf_counter_init(counter);
-                break;
-
-        default:
-                break;
-        }
-done:
-        err = 0;
-        if (!pmu)
-                err = -EINVAL;
-        else if (IS_ERR(pmu))
-                err = PTR_ERR(pmu);
-
-        if (err) {
-                if (counter->ns)
-                        put_pid_ns(counter->ns);
-                kfree(counter);
-                return ERR_PTR(err);
-        }
-
-        counter->pmu = pmu;
-
-        if (!counter->parent) {
-                atomic_inc(&nr_counters);
-                if (counter->attr.mmap)
-                        atomic_inc(&nr_mmap_counters);
-                if (counter->attr.comm)
-                        atomic_inc(&nr_comm_counters);
-                if (counter->attr.task)
-                        atomic_inc(&nr_task_counters);
-        }
-
-        return counter;
-}
-
-static int perf_copy_attr(struct perf_counter_attr __user *uattr,
-                          struct perf_counter_attr *attr)
-{
-        int ret;
-        u32 size;
-
-        if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
-                return -EFAULT;
-
-        /*
-         * zero the full structure, so that a short copy will be nice.
-         */
-        memset(attr, 0, sizeof(*attr));
-
-        ret = get_user(size, &uattr->size);
-        if (ret)
-                return ret;
-
-        if (size > PAGE_SIZE)   /* silly large */
-                goto err_size;
-
-        if (!size)              /* abi compat */
-                size = PERF_ATTR_SIZE_VER0;
-
-        if (size < PERF_ATTR_SIZE_VER0)
-                goto err_size;
-
-        /*
-         * If we're handed a bigger struct than we know of,
-         * ensure all the unknown bits are 0.
-         */
-        if (size > sizeof(*attr)) {
-                unsigned long val;
-                unsigned long __user *addr;
-                unsigned long __user *end;
-
-                addr = PTR_ALIGN((void __user *)uattr + sizeof(*attr),
-                                sizeof(unsigned long));
-                end  = PTR_ALIGN((void __user *)uattr + size,
-                                sizeof(unsigned long));
-
-                for (; addr < end; addr += sizeof(unsigned long)) {
-                        ret = get_user(val, addr);
-                        if (ret)
-                                return ret;
-                        if (val)
-                                goto err_size;
-                }
-                size = sizeof(*attr);
-        }
-
-        ret = copy_from_user(attr, uattr, size);
-        if (ret)
-                return -EFAULT;
-
-        /*
-         * If the type exists, the corresponding creation will verify
-         * the attr->config.
-         */
-        if (attr->type >= PERF_TYPE_MAX)
-                return -EINVAL;
-
-        if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
-                return -EINVAL;
-
-        if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
-                return -EINVAL;
-
-        if (attr->read_format & ~(PERF_FORMAT_MAX-1))
-                return -EINVAL;
-
-out:
-        return ret;
-
-err_size:
-        put_user(sizeof(*attr), &uattr->size);
-        ret = -E2BIG;
-        goto out;
-}
-
-int perf_counter_set_output(struct perf_counter *counter, int output_fd)
-{
-        struct perf_counter *output_counter = NULL;
-        struct file *output_file = NULL;
-        struct perf_counter *old_output;
-        int fput_needed = 0;
-        int ret = -EINVAL;
-
-        if (!output_fd)
-                goto set;
-
-        output_file = fget_light(output_fd, &fput_needed);
-        if (!output_file)
-                return -EBADF;
-
-        if (output_file->f_op != &perf_fops)
-                goto out;
-
-        output_counter = output_file->private_data;
-
-        /* Don't chain output fds */
-        if (output_counter->output)
-                goto out;
-
-        /* Don't set an output fd when we already have an output channel */
-        if (counter->data)
-                goto out;
-
-        atomic_long_inc(&output_file->f_count);
-
-set:
-        mutex_lock(&counter->mmap_mutex);
-        old_output = counter->output;
-        rcu_assign_pointer(counter->output, output_counter);
-        mutex_unlock(&counter->mmap_mutex);
-
-        if (old_output) {
-                /*
-                 * we need to make sure no existing perf_output_*()
-                 * is still referencing this counter.
-                 */
-                synchronize_rcu();
-                fput(old_output->filp);
-        }
-
-        ret = 0;
-out:
-        fput_light(output_file, fput_needed);
-        return ret;
-}
-
-/**
- * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
- *
- * @attr_uptr:  event type attributes for monitoring/sampling
- * @pid:                target pid
- * @cpu:                target cpu
- * @group_fd:           group leader counter fd
- */
-SYSCALL_DEFINE5(perf_counter_open,
-                struct perf_counter_attr __user *, attr_uptr,
-                pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
-{
-        struct perf_counter *counter, *group_leader;
-        struct perf_counter_attr attr;
-        struct perf_counter_context *ctx;
-        struct file *counter_file = NULL;
-        struct file *group_file = NULL;
-        int fput_needed = 0;
-        int fput_needed2 = 0;
-        int err;
-
-        /* for future expandability... */
-        if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT))
-                return -EINVAL;
-
-        err = perf_copy_attr(attr_uptr, &attr);
-        if (err)
-                return err;
-
-        if (!attr.exclude_kernel) {
-                if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
-                        return -EACCES;
-        }
-
-        if (attr.freq) {
-                if (attr.sample_freq > sysctl_perf_counter_sample_rate)
-                        return -EINVAL;
-        }
-
-        /*
-         * Get the target context (task or percpu):
-         */
-        ctx = find_get_context(pid, cpu);
-        if (IS_ERR(ctx))
-                return PTR_ERR(ctx);
-
-        /*
-         * Look up the group leader (we will attach this counter to it):
-         */
-        group_leader = NULL;
-        if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) {
-                err = -EINVAL;
-                group_file = fget_light(group_fd, &fput_needed);
-                if (!group_file)
-                        goto err_put_context;
-                if (group_file->f_op != &perf_fops)
-                        goto err_put_context;
-
-                group_leader = group_file->private_data;
-                /*
-                 * Do not allow a recursive hierarchy (this new sibling
-                 * becoming part of another group-sibling):
-                 */
-                if (group_leader->group_leader != group_leader)
-                        goto err_put_context;
-                /*
-                 * Do not allow to attach to a group in a different
-                 * task or CPU context:
-                 */
-                if (group_leader->ctx != ctx)
-                        goto err_put_context;
-                /*
-                 * Only a group leader can be exclusive or pinned
-                 */
-                if (attr.exclusive || attr.pinned)
-                        goto err_put_context;
-        }
-
-        counter = perf_counter_alloc(&attr, cpu, ctx, group_leader,
-                                     NULL, GFP_KERNEL);
-        err = PTR_ERR(counter);
-        if (IS_ERR(counter))
-                goto err_put_context;
-
-        err = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
-        if (err < 0)
-                goto err_free_put_context;
-
-        counter_file = fget_light(err, &fput_needed2);
-        if (!counter_file)
-                goto err_free_put_context;
-
-        if (flags & PERF_FLAG_FD_OUTPUT) {
-                err = perf_counter_set_output(counter, group_fd);
-                if (err)
-                        goto err_fput_free_put_context;
-        }
-
-        counter->filp = counter_file;
-        WARN_ON_ONCE(ctx->parent_ctx);
-        mutex_lock(&ctx->mutex);
-        perf_install_in_context(ctx, counter, cpu);
-        ++ctx->generation;
-        mutex_unlock(&ctx->mutex);
-
-        counter->owner = current;
-        get_task_struct(current);
-        mutex_lock(&current->perf_counter_mutex);
-        list_add_tail(&counter->owner_entry, &current->perf_counter_list);
-        mutex_unlock(&current->perf_counter_mutex);
-
-err_fput_free_put_context:
-        fput_light(counter_file, fput_needed2);
-
-err_free_put_context:
-        if (err < 0)
-                kfree(counter);
-
-err_put_context:
-        if (err < 0)
-                put_ctx(ctx);
-
-        fput_light(group_file, fput_needed);
-
-        return err;
-}
-
-/*
- * inherit a counter from parent task to child task:
- */
-static struct perf_counter *
-inherit_counter(struct perf_counter *parent_counter,
-              struct task_struct *parent,
-              struct perf_counter_context *parent_ctx,
-              struct task_struct *child,
-              struct perf_counter *group_leader,
-              struct perf_counter_context *child_ctx)
-{
-        struct perf_counter *child_counter;
-
-        /*
-         * Instead of creating recursive hierarchies of counters,
-         * we link inherited counters back to the original parent,
-         * which has a filp for sure, which we use as the reference
-         * count:
-         */
-        if (parent_counter->parent)
-                parent_counter = parent_counter->parent;
-
-        child_counter = perf_counter_alloc(&parent_counter->attr,
-                                           parent_counter->cpu, child_ctx,
-                                           group_leader, parent_counter,
-                                           GFP_KERNEL);
-        if (IS_ERR(child_counter))
-                return child_counter;
-        get_ctx(child_ctx);
-
-        /*
-         * Make the child state follow the state of the parent counter,
-         * not its attr.disabled bit.  We hold the parent's mutex,
-         * so we won't race with perf_counter_{en, dis}able_family.
-         */
-        if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE)
-                child_counter->state = PERF_COUNTER_STATE_INACTIVE;
-        else
-                child_counter->state = PERF_COUNTER_STATE_OFF;
-
-        if (parent_counter->attr.freq)
-                child_counter->hw.sample_period = parent_counter->hw.sample_period;
-
-        /*
-         * Link it up in the child's context:
-         */
-        add_counter_to_ctx(child_counter, child_ctx);
-
-        /*
-         * Get a reference to the parent filp - we will fput it
-         * when the child counter exits. This is safe to do because
-         * we are in the parent and we know that the filp still
-         * exists and has a nonzero count:
-         */
-        atomic_long_inc(&parent_counter->filp->f_count);
-
-        /*
-         * Link this into the parent counter's child list
-         */
-        WARN_ON_ONCE(parent_counter->ctx->parent_ctx);
-        mutex_lock(&parent_counter->child_mutex);
-        list_add_tail(&child_counter->child_list, &parent_counter->child_list);
-        mutex_unlock(&parent_counter->child_mutex);
-
-        return child_counter;
-}
-
-static int inherit_group(struct perf_counter *parent_counter,
-              struct task_struct *parent,
-              struct perf_counter_context *parent_ctx,
-              struct task_struct *child,
-              struct perf_counter_context *child_ctx)
-{
-        struct perf_counter *leader;
-        struct perf_counter *sub;
-        struct perf_counter *child_ctr;
-
-        leader = inherit_counter(parent_counter, parent, parent_ctx,
-                                 child, NULL, child_ctx);
-        if (IS_ERR(leader))
-                return PTR_ERR(leader);
-        list_for_each_entry(sub, &parent_counter->sibling_list, list_entry) {
-                child_ctr = inherit_counter(sub, parent, parent_ctx,
-                                            child, leader, child_ctx);
-                if (IS_ERR(child_ctr))
-                        return PTR_ERR(child_ctr);
-        }
-        return 0;
-}
-
-static void sync_child_counter(struct perf_counter *child_counter,
-                               struct task_struct *child)
-{
-        struct perf_counter *parent_counter = child_counter->parent;
-        u64 child_val;
-
-        if (child_counter->attr.inherit_stat)
-                perf_counter_read_event(child_counter, child);
-
-        child_val = atomic64_read(&child_counter->count);
-
-        /*
-         * Add back the child's count to the parent's count:
-         */
-        atomic64_add(child_val, &parent_counter->count);
-        atomic64_add(child_counter->total_time_enabled,
-                     &parent_counter->child_total_time_enabled);
-        atomic64_add(child_counter->total_time_running,
-                     &parent_counter->child_total_time_running);
-
-        /*
-         * Remove this counter from the parent's list
-         */
-        WARN_ON_ONCE(parent_counter->ctx->parent_ctx);
-        mutex_lock(&parent_counter->child_mutex);
-        list_del_init(&child_counter->child_list);
-        mutex_unlock(&parent_counter->child_mutex);
-
-        /*
-         * Release the parent counter, if this was the last
-         * reference to it.
-         */
-        fput(parent_counter->filp);
-}
-
-static void
-__perf_counter_exit_task(struct perf_counter *child_counter,
-                         struct perf_counter_context *child_ctx,
-                         struct task_struct *child)
-{
-        struct perf_counter *parent_counter;
-
-        update_counter_times(child_counter);
-        perf_counter_remove_from_context(child_counter);
-
-        parent_counter = child_counter->parent;
-        /*
-         * It can happen that parent exits first, and has counters
-         * that are still around due to the child reference. These
-         * counters need to be zapped - but otherwise linger.
-         */
-        if (parent_counter) {
-                sync_child_counter(child_counter, child);
-                free_counter(child_counter);
-        }
-}
-
-/*
- * When a child task exits, feed back counter values to parent counters.
- */
-void perf_counter_exit_task(struct task_struct *child)
-{
-        struct perf_counter *child_counter, *tmp;
-        struct perf_counter_context *child_ctx;
-        unsigned long flags;
-
-        if (likely(!child->perf_counter_ctxp)) {
-                perf_counter_task(child, NULL, 0);
-                return;
-        }
-
-        local_irq_save(flags);
-        /*
-         * We can't reschedule here because interrupts are disabled,
-         * and either child is current or it is a task that can't be
-         * scheduled, so we are now safe from rescheduling changing
-         * our context.
-         */
-        child_ctx = child->perf_counter_ctxp;
-        __perf_counter_task_sched_out(child_ctx);
-
-        /*
-         * Take the context lock here so that if find_get_context is
-         * reading child->perf_counter_ctxp, we wait until it has
-         * incremented the context's refcount before we do put_ctx below.
-         */
-        spin_lock(&child_ctx->lock);
-        child->perf_counter_ctxp = NULL;
-        /*
-         * If this context is a clone; unclone it so it can't get
-         * swapped to another process while we're removing all
-         * the counters from it.
-         */
-        unclone_ctx(child_ctx);
-        spin_unlock_irqrestore(&child_ctx->lock, flags);
-
-        /*
-         * Report the task dead after unscheduling the counters so that we
-         * won't get any samples after PERF_EVENT_EXIT. We can however still
-         * get a few PERF_EVENT_READ events.
-         */
-        perf_counter_task(child, child_ctx, 0);
-
-        /*
-         * We can recurse on the same lock type through:
-         *
-         *   __perf_counter_exit_task()
-         *     sync_child_counter()
-         *       fput(parent_counter->filp)
-         *         perf_release()
-         *           mutex_lock(&ctx->mutex)
-         *
-         * But since its the parent context it won't be the same instance.
-         */
-        mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING);
-
-again:
-        list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list,
-                                 list_entry)
-                __perf_counter_exit_task(child_counter, child_ctx, child);
-
-        /*
-         * If the last counter was a group counter, it will have appended all
-         * its siblings to the list, but we obtained 'tmp' before that which
-         * will still point to the list head terminating the iteration.
-         */
-        if (!list_empty(&child_ctx->counter_list))
-                goto again;
-
-        mutex_unlock(&child_ctx->mutex);
-
-        put_ctx(child_ctx);
-}
-
-/*
- * free an unexposed, unused context as created by inheritance by
- * init_task below, used by fork() in case of fail.
- */
-void perf_counter_free_task(struct task_struct *task)
-{
-        struct perf_counter_context *ctx = task->perf_counter_ctxp;
-        struct perf_counter *counter, *tmp;
-
-        if (!ctx)
-                return;
-
-        mutex_lock(&ctx->mutex);
-again:
-        list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) {
-                struct perf_counter *parent = counter->parent;
-
-                if (WARN_ON_ONCE(!parent))
-                        continue;
-
-                mutex_lock(&parent->child_mutex);
-                list_del_init(&counter->child_list);
-                mutex_unlock(&parent->child_mutex);
-
-                fput(parent->filp);
-
-                list_del_counter(counter, ctx);
-                free_counter(counter);
-        }
-
-        if (!list_empty(&ctx->counter_list))
-                goto again;
-
-        mutex_unlock(&ctx->mutex);
-
-        put_ctx(ctx);
-}
-
-/*
- * Initialize the perf_counter context in task_struct
- */
-int perf_counter_init_task(struct task_struct *child)
-{
-        struct perf_counter_context *child_ctx, *parent_ctx;
-        struct perf_counter_context *cloned_ctx;
-        struct perf_counter *counter;
-        struct task_struct *parent = current;
-        int inherited_all = 1;
-        int ret = 0;
-
-        child->perf_counter_ctxp = NULL;
-
-        mutex_init(&child->perf_counter_mutex);
-        INIT_LIST_HEAD(&child->perf_counter_list);
-
-        if (likely(!parent->perf_counter_ctxp))
-                return 0;
-
-        /*
-         * This is executed from the parent task context, so inherit
-         * counters that have been marked for cloning.
-         * First allocate and initialize a context for the child.
-         */
-
-        child_ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL);
-        if (!child_ctx)
-                return -ENOMEM;
-
-        __perf_counter_init_context(child_ctx, child);
-        child->perf_counter_ctxp = child_ctx;
-        get_task_struct(child);
-
-        /*
-         * If the parent's context is a clone, pin it so it won't get
-         * swapped under us.
-         */
-        parent_ctx = perf_pin_task_context(parent);
-
-        /*
-         * No need to check if parent_ctx != NULL here; since we saw
-         * it non-NULL earlier, the only reason for it to become NULL
-         * is if we exit, and since we're currently in the middle of
-         * a fork we can't be exiting at the same time.
-         */
-
-        /*
-         * Lock the parent list. No need to lock the child - not PID
-         * hashed yet and not running, so nobody can access it.
-         */
-        mutex_lock(&parent_ctx->mutex);
-
-        /*
-         * We dont have to disable NMIs - we are only looking at
-         * the list, not manipulating it:
-         */
-        list_for_each_entry_rcu(counter, &parent_ctx->event_list, event_entry) {
-                if (counter != counter->group_leader)
-                        continue;
-
-                if (!counter->attr.inherit) {
-                        inherited_all = 0;
-                        continue;
-                }
-
-                ret = inherit_group(counter, parent, parent_ctx,
-                                             child, child_ctx);
-                if (ret) {
-                        inherited_all = 0;
-                        break;
-                }
-        }
-
-        if (inherited_all) {
-                /*
-                 * Mark the child context as a clone of the parent
-                 * context, or of whatever the parent is a clone of.
-                 * Note that if the parent is a clone, it could get
-                 * uncloned at any point, but that doesn't matter
-                 * because the list of counters and the generation
-                 * count can't have changed since we took the mutex.
-                 */
-                cloned_ctx = rcu_dereference(parent_ctx->parent_ctx);
-                if (cloned_ctx) {
-                        child_ctx->parent_ctx = cloned_ctx;
-                        child_ctx->parent_gen = parent_ctx->parent_gen;
-                } else {
-                        child_ctx->parent_ctx = parent_ctx;
-                        child_ctx->parent_gen = parent_ctx->generation;
-                }
-                get_ctx(child_ctx->parent_ctx);
-        }
-
-        mutex_unlock(&parent_ctx->mutex);
-
-        perf_unpin_context(parent_ctx);
-
-        return ret;
-}
-
-static void __cpuinit perf_counter_init_cpu(int cpu)
-{
-        struct perf_cpu_context *cpuctx;
-
-        cpuctx = &per_cpu(perf_cpu_context, cpu);
-        __perf_counter_init_context(&cpuctx->ctx, NULL);
-
-        spin_lock(&perf_resource_lock);
-        cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu;
-        spin_unlock(&perf_resource_lock);
-
-        hw_perf_counter_setup(cpu);
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-static void __perf_counter_exit_cpu(void *info)
-{
-        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-        struct perf_counter_context *ctx = &cpuctx->ctx;
-        struct perf_counter *counter, *tmp;
-
-        list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry)
-                __perf_counter_remove_from_context(counter);
-}
-static void perf_counter_exit_cpu(int cpu)
-{
-        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
-        struct perf_counter_context *ctx = &cpuctx->ctx;
-
-        mutex_lock(&ctx->mutex);
-        smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1);
-        mutex_unlock(&ctx->mutex);
-}
-#else
-static inline void perf_counter_exit_cpu(int cpu) { }
-#endif
-
-static int __cpuinit
-perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
-{
-        unsigned int cpu = (long)hcpu;
-
-        switch (action) {
-
-        case CPU_UP_PREPARE:
-        case CPU_UP_PREPARE_FROZEN:
-                perf_counter_init_cpu(cpu);
-                break;
-
-        case CPU_ONLINE:
-        case CPU_ONLINE_FROZEN:
-                hw_perf_counter_setup_online(cpu);
-                break;
-
-        case CPU_DOWN_PREPARE:
-        case CPU_DOWN_PREPARE_FROZEN:
-                perf_counter_exit_cpu(cpu);
-                break;
-
-        default:
-                break;
-        }
-
-        return NOTIFY_OK;
-}
-
-/*
- * This has to have a higher priority than migration_notifier in sched.c.
- */
-static struct notifier_block __cpuinitdata perf_cpu_nb = {
-        .notifier_call          = perf_cpu_notify,
-        .priority               = 20,
-};
-
-void __init perf_counter_init(void)
-{
-        perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
-                        (void *)(long)smp_processor_id());
-        perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,
-                        (void *)(long)smp_processor_id());
-        register_cpu_notifier(&perf_cpu_nb);
-}
-
-static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf)
-{
-        return sprintf(buf, "%d\n", perf_reserved_percpu);
-}
-
-static ssize_t
-perf_set_reserve_percpu(struct sysdev_class *class,
-                        const char *buf,
-                        size_t count)
-{
-        struct perf_cpu_context *cpuctx;
-        unsigned long val;
-        int err, cpu, mpt;
-
-        err = strict_strtoul(buf, 10, &val);
-        if (err)
-                return err;
-        if (val > perf_max_counters)
-                return -EINVAL;
-
-        spin_lock(&perf_resource_lock);
-        perf_reserved_percpu = val;
-        for_each_online_cpu(cpu) {
-                cpuctx = &per_cpu(perf_cpu_context, cpu);
-                spin_lock_irq(&cpuctx->ctx.lock);
-                mpt = min(perf_max_counters - cpuctx->ctx.nr_counters,
-                          perf_max_counters - perf_reserved_percpu);
-                cpuctx->max_pertask = mpt;
-                spin_unlock_irq(&cpuctx->ctx.lock);
-        }
-        spin_unlock(&perf_resource_lock);
-
-        return count;
-}
-
-static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf)
-{
-        return sprintf(buf, "%d\n", perf_overcommit);
-}
-
-static ssize_t
-perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
-{
-        unsigned long val;
-        int err;
-
-        err = strict_strtoul(buf, 10, &val);
-        if (err)
-                return err;
-        if (val > 1)
-                return -EINVAL;
-
-        spin_lock(&perf_resource_lock);
-        perf_overcommit = val;
-        spin_unlock(&perf_resource_lock);
-
-        return count;
-}
-
-static SYSDEV_CLASS_ATTR(
-                                reserve_percpu,
-                                0644,
-                                perf_show_reserve_percpu,
-                                perf_set_reserve_percpu
-                        );
-
-static SYSDEV_CLASS_ATTR(
-                                overcommit,
-                                0644,
-                                perf_show_overcommit,
-                                perf_set_overcommit
-                        );
-
-static struct attribute *perfclass_attrs[] = {
-        &attr_reserve_percpu.attr,
-        &attr_overcommit.attr,
-        NULL
-};
-
-static struct attribute_group perfclass_attr_group = {
-        .attrs                  = perfclass_attrs,
-        .name                   = "perf_counters",
-};
-
-static int __init perf_counter_sysfs_init(void)
-{
-        return sysfs_create_group(&cpu_sysdev_class.kset.kobj,
-                                  &perfclass_attr_group);
-}
-device_initcall(perf_counter_sysfs_init);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
new file mode 100644
index 000000000000..9d0b5c665883
--- /dev/null
+++ b/kernel/perf_event.c
@@ -0,0 +1,5108 @@
+/*
+ * Performance events core code:
+ *
+ *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * For licensing details see kernel-base/COPYING
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/sysfs.h>
+#include <linux/dcache.h>
+#include <linux/percpu.h>
+#include <linux/ptrace.h>
+#include <linux/vmstat.h>
+#include <linux/vmalloc.h>
+#include <linux/hardirq.h>
+#include <linux/rculist.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/anon_inodes.h>
+#include <linux/kernel_stat.h>
+#include <linux/perf_event.h>
+
+#include <asm/irq_regs.h>
+
+/*
+ * Each CPU has a list of per CPU events:
+ */
+DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
+
+int perf_max_events __read_mostly = 1;
+static int perf_reserved_percpu __read_mostly;
+static int perf_overcommit __read_mostly = 1;
+
+static atomic_t nr_events __read_mostly;
+static atomic_t nr_mmap_events __read_mostly;
+static atomic_t nr_comm_events __read_mostly;
+static atomic_t nr_task_events __read_mostly;
+
+/*
+ * perf event paranoia level:
+ *  -1 - not paranoid at all
+ *   0 - disallow raw tracepoint access for unpriv
+ *   1 - disallow cpu events for unpriv
+ *   2 - disallow kernel profiling for unpriv
+ */
+int sysctl_perf_event_paranoid __read_mostly = 1;
+
+static inline bool perf_paranoid_tracepoint_raw(void)
+{
+        return sysctl_perf_event_paranoid > -1;
+}
+
+static inline bool perf_paranoid_cpu(void)
+{
+        return sysctl_perf_event_paranoid > 0;
+}
+
+static inline bool perf_paranoid_kernel(void)
+{
+        return sysctl_perf_event_paranoid > 1;
+}
+
+int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */
+
+/*
+ * max perf event sample rate
+ */
+int sysctl_perf_event_sample_rate __read_mostly = 100000;
+
+static atomic64_t perf_event_id;
+
+/*
+ * Lock for (sysadmin-configurable) event reservations:
+ */
+static DEFINE_SPINLOCK(perf_resource_lock);
+
+/*
+ * Architecture provided APIs - weak aliases:
+ */
+extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event)
+{
+        return NULL;
+}
+
+void __weak hw_perf_disable(void)               { barrier(); }
+void __weak hw_perf_enable(void)                { barrier(); }
+
+void __weak hw_perf_event_setup(int cpu)        { barrier(); }
+void __weak hw_perf_event_setup_online(int cpu) { barrier(); }
+
+int __weak
+hw_perf_group_sched_in(struct perf_event *group_leader,
+               struct perf_cpu_context *cpuctx,
+               struct perf_event_context *ctx, int cpu)
+{
+        return 0;
+}
+
+void __weak perf_event_print_debug(void)        { }
+
+static DEFINE_PER_CPU(int, perf_disable_count);
+
+void __perf_disable(void)
+{
+        __get_cpu_var(perf_disable_count)++;
+}
+
+bool __perf_enable(void)
+{
+        return !--__get_cpu_var(perf_disable_count);
+}
+
+void perf_disable(void)
+{
+        __perf_disable();
+        hw_perf_disable();
+}
+
+void perf_enable(void)
+{
+        if (__perf_enable())
+                hw_perf_enable();
+}
+
+static void get_ctx(struct perf_event_context *ctx)
+{
+        WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
+}
+
+static void free_ctx(struct rcu_head *head)
+{
+        struct perf_event_context *ctx;
+
+        ctx = container_of(head, struct perf_event_context, rcu_head);
+        kfree(ctx);
+}
+
+static void put_ctx(struct perf_event_context *ctx)
+{
+        if (atomic_dec_and_test(&ctx->refcount)) {
+                if (ctx->parent_ctx)
+                        put_ctx(ctx->parent_ctx);
+                if (ctx->task)
+                        put_task_struct(ctx->task);
+                call_rcu(&ctx->rcu_head, free_ctx);
+        }
+}
+
+static void unclone_ctx(struct perf_event_context *ctx)
+{
+        if (ctx->parent_ctx) {
+                put_ctx(ctx->parent_ctx);
+                ctx->parent_ctx = NULL;
+        }
+}
+
+/*
+ * If we inherit events we want to return the parent event id
+ * to userspace.
+ */
+static u64 primary_event_id(struct perf_event *event)
+{
+        u64 id = event->id;
+
+        if (event->parent)
+                id = event->parent->id;
+
+        return id;
+}
+
+/*
+ * Get the perf_event_context for a task and lock it.
+ * This has to cope with with the fact that until it is locked,
+ * the context could get moved to another task.
+ */
+static struct perf_event_context *
+perf_lock_task_context(struct task_struct *task, unsigned long *flags)
+{
+        struct perf_event_context *ctx;
+
+        rcu_read_lock();
+ retry:
+        ctx = rcu_dereference(task->perf_event_ctxp);
+        if (ctx) {
+                /*
+                 * If this context is a clone of another, it might
+                 * get swapped for another underneath us by
+                 * perf_event_task_sched_out, though the
+                 * rcu_read_lock() protects us from any context
+                 * getting freed.  Lock the context and check if it
+                 * got swapped before we could get the lock, and retry
+                 * if so.  If we locked the right context, then it
+                 * can't get swapped on us any more.
+                 */
+                spin_lock_irqsave(&ctx->lock, *flags);
+                if (ctx != rcu_dereference(task->perf_event_ctxp)) {
+                        spin_unlock_irqrestore(&ctx->lock, *flags);
+                        goto retry;
+                }
+
+                if (!atomic_inc_not_zero(&ctx->refcount)) {
+                        spin_unlock_irqrestore(&ctx->lock, *flags);
+                        ctx = NULL;
+                }
+        }
+        rcu_read_unlock();
+        return ctx;
+}
+
+/*
+ * Get the context for a task and increment its pin_count so it
+ * can't get swapped to another task.  This also increments its
+ * reference count so that the context can't get freed.
+ */
+static struct perf_event_context *perf_pin_task_context(struct task_struct *task)
+{
+        struct perf_event_context *ctx;
+        unsigned long flags;
+
+        ctx = perf_lock_task_context(task, &flags);
+        if (ctx) {
+                ++ctx->pin_count;
+                spin_unlock_irqrestore(&ctx->lock, flags);
+        }
+        return ctx;
+}
+
+static void perf_unpin_context(struct perf_event_context *ctx)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&ctx->lock, flags);
+        --ctx->pin_count;
+        spin_unlock_irqrestore(&ctx->lock, flags);
+        put_ctx(ctx);
+}
+
+/*
+ * Add a event from the lists for its context.
+ * Must be called with ctx->mutex and ctx->lock held.
+ */
+static void
+list_add_event(struct perf_event *event, struct perf_event_context *ctx)
+{
+        struct perf_event *group_leader = event->group_leader;
+
+        /*
+         * Depending on whether it is a standalone or sibling event,
+         * add it straight to the context's event list, or to the group
+         * leader's sibling list:
+         */
+        if (group_leader == event)
+                list_add_tail(&event->group_entry, &ctx->group_list);
+        else {
+                list_add_tail(&event->group_entry, &group_leader->sibling_list);
+                group_leader->nr_siblings++;
+        }
+
+        list_add_rcu(&event->event_entry, &ctx->event_list);
+        ctx->nr_events++;
+        if (event->attr.inherit_stat)
+                ctx->nr_stat++;
+}
+
+/*
+ * Remove a event from the lists for its context.
+ * Must be called with ctx->mutex and ctx->lock held.
+ */
+static void
+list_del_event(struct perf_event *event, struct perf_event_context *ctx)
+{
+        struct perf_event *sibling, *tmp;
+
+        if (list_empty(&event->group_entry))
+                return;
+        ctx->nr_events--;
+        if (event->attr.inherit_stat)
+                ctx->nr_stat--;
+
+        list_del_init(&event->group_entry);
+        list_del_rcu(&event->event_entry);
+
+        if (event->group_leader != event)
+                event->group_leader->nr_siblings--;
+
+        /*
+         * If this was a group event with sibling events then
+         * upgrade the siblings to singleton events by adding them
+         * to the context list directly:
+         */
+        list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
+
+                list_move_tail(&sibling->group_entry, &ctx->group_list);
+                sibling->group_leader = sibling;
+        }
+}
+
+static void
+event_sched_out(struct perf_event *event,
+                  struct perf_cpu_context *cpuctx,
+                  struct perf_event_context *ctx)
+{
+        if (event->state != PERF_EVENT_STATE_ACTIVE)
+                return;
+
+        event->state = PERF_EVENT_STATE_INACTIVE;
+        if (event->pending_disable) {
+                event->pending_disable = 0;
+                event->state = PERF_EVENT_STATE_OFF;
+        }
+        event->tstamp_stopped = ctx->time;
+        event->pmu->disable(event);
+        event->oncpu = -1;
+
+        if (!is_software_event(event))
+                cpuctx->active_oncpu--;
+        ctx->nr_active--;
+        if (event->attr.exclusive || !cpuctx->active_oncpu)
+                cpuctx->exclusive = 0;
+}
+
+static void
+group_sched_out(struct perf_event *group_event,
+                struct perf_cpu_context *cpuctx,
+                struct perf_event_context *ctx)
+{
+        struct perf_event *event;
+
+        if (group_event->state != PERF_EVENT_STATE_ACTIVE)
+                return;
+
+        event_sched_out(group_event, cpuctx, ctx);
+
+        /*
+         * Schedule out siblings (if any):
+         */
+        list_for_each_entry(event, &group_event->sibling_list, group_entry)
+                event_sched_out(event, cpuctx, ctx);
+
+        if (group_event->attr.exclusive)
+                cpuctx->exclusive = 0;
+}
+
+/*
+ * Cross CPU call to remove a performance event
+ *
+ * We disable the event on the hardware level first. After that we
+ * remove it from the context list.
+ */
+static void __perf_event_remove_from_context(void *info)
+{
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        struct perf_event *event = info;
+        struct perf_event_context *ctx = event->ctx;
+
+        /*
+         * If this is a task context, we need to check whether it is
+         * the current task context of this cpu. If not it has been
+         * scheduled out before the smp call arrived.
+         */
+        if (ctx->task && cpuctx->task_ctx != ctx)
+                return;
+
+        spin_lock(&ctx->lock);
+        /*
+         * Protect the list operation against NMI by disabling the
+         * events on a global level.
+         */
+        perf_disable();
+
+        event_sched_out(event, cpuctx, ctx);
+
+        list_del_event(event, ctx);
+
+        if (!ctx->task) {
+                /*
+                 * Allow more per task events with respect to the
+                 * reservation:
+                 */
+                cpuctx->max_pertask =
+                        min(perf_max_events - ctx->nr_events,
+                            perf_max_events - perf_reserved_percpu);
+        }
+
+        perf_enable();
+        spin_unlock(&ctx->lock);
+}
+
+
+/*
+ * Remove the event from a task's (or a CPU's) list of events.
+ *
+ * Must be called with ctx->mutex held.
+ *
+ * CPU events are removed with a smp call. For task events we only
+ * call when the task is on a CPU.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This is OK when called from perf_release since
+ * that only calls us on the top-level context, which can't be a clone.
+ * When called from perf_event_exit_task, it's OK because the
+ * context has been detached from its task.
+ */
+static void perf_event_remove_from_context(struct perf_event *event)
+{
+        struct perf_event_context *ctx = event->ctx;
+        struct task_struct *task = ctx->task;
+
+        if (!task) {
+                /*
+                 * Per cpu events are removed via an smp call and
+                 * the removal is always sucessful.
+                 */
+                smp_call_function_single(event->cpu,
+                                         __perf_event_remove_from_context,
+                                         event, 1);
+                return;
+        }
+
+retry:
+        task_oncpu_function_call(task, __perf_event_remove_from_context,
+                                 event);
+
+        spin_lock_irq(&ctx->lock);
+        /*
+         * If the context is active we need to retry the smp call.
+         */
+        if (ctx->nr_active && !list_empty(&event->group_entry)) {
+                spin_unlock_irq(&ctx->lock);
+                goto retry;
+        }
+
+        /*
+         * The lock prevents that this context is scheduled in so we
+         * can remove the event safely, if the call above did not
+         * succeed.
+         */
+        if (!list_empty(&event->group_entry)) {
+                list_del_event(event, ctx);
+        }
+        spin_unlock_irq(&ctx->lock);
+}
+
+static inline u64 perf_clock(void)
+{
+        return cpu_clock(smp_processor_id());
+}
+
+/*
+ * Update the record of the current time in a context.
+ */
+static void update_context_time(struct perf_event_context *ctx)
+{
+        u64 now = perf_clock();
+
+        ctx->time += now - ctx->timestamp;
+        ctx->timestamp = now;
+}
+
+/*
+ * Update the total_time_enabled and total_time_running fields for a event.
+ */
+static void update_event_times(struct perf_event *event)
+{
+        struct perf_event_context *ctx = event->ctx;
+        u64 run_end;
+
+        if (event->state < PERF_EVENT_STATE_INACTIVE ||
+            event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
+                return;
+
+        event->total_time_enabled = ctx->time - event->tstamp_enabled;
+
+        if (event->state == PERF_EVENT_STATE_INACTIVE)
+                run_end = event->tstamp_stopped;
+        else
+                run_end = ctx->time;
+
+        event->total_time_running = run_end - event->tstamp_running;
+}
+
+/*
+ * Update total_time_enabled and total_time_running for all events in a group.
+ */
+static void update_group_times(struct perf_event *leader)
+{
+        struct perf_event *event;
+
+        update_event_times(leader);
+        list_for_each_entry(event, &leader->sibling_list, group_entry)
+                update_event_times(event);
+}
+
+/*
+ * Cross CPU call to disable a performance event
+ */
+static void __perf_event_disable(void *info)
+{
+        struct perf_event *event = info;
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        struct perf_event_context *ctx = event->ctx;
+
+        /*
+         * If this is a per-task event, need to check whether this
+         * event's task is the current task on this cpu.
+         */
+        if (ctx->task && cpuctx->task_ctx != ctx)
+                return;
+
+        spin_lock(&ctx->lock);
+
+        /*
+         * If the event is on, turn it off.
+         * If it is in error state, leave it in error state.
+         */
+        if (event->state >= PERF_EVENT_STATE_INACTIVE) {
+                update_context_time(ctx);
+                update_group_times(event);
+                if (event == event->group_leader)
+                        group_sched_out(event, cpuctx, ctx);
+                else
+                        event_sched_out(event, cpuctx, ctx);
+                event->state = PERF_EVENT_STATE_OFF;
+        }
+
+        spin_unlock(&ctx->lock);
+}
+
+/*
+ * Disable a event.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This condition is satisifed when called through
+ * perf_event_for_each_child or perf_event_for_each because they
+ * hold the top-level event's child_mutex, so any descendant that
+ * goes to exit will block in sync_child_event.
+ * When called from perf_pending_event it's OK because event->ctx
+ * is the current context on this CPU and preemption is disabled,
+ * hence we can't get into perf_event_task_sched_out for this context.
+ */
+static void perf_event_disable(struct perf_event *event)
+{
+        struct perf_event_context *ctx = event->ctx;
+        struct task_struct *task = ctx->task;
+
+        if (!task) {
+                /*
+                 * Disable the event on the cpu that it's on
+                 */
+                smp_call_function_single(event->cpu, __perf_event_disable,
+                                         event, 1);
+                return;
+        }
+
+ retry:
+        task_oncpu_function_call(task, __perf_event_disable, event);
+
+        spin_lock_irq(&ctx->lock);
+        /*
+         * If the event is still active, we need to retry the cross-call.
+         */
+        if (event->state == PERF_EVENT_STATE_ACTIVE) {
+                spin_unlock_irq(&ctx->lock);
+                goto retry;
+        }
+
+        /*
+         * Since we have the lock this context can't be scheduled
+         * in, so we can change the state safely.
+         */
+        if (event->state == PERF_EVENT_STATE_INACTIVE) {
+                update_group_times(event);
+                event->state = PERF_EVENT_STATE_OFF;
+        }
+
+        spin_unlock_irq(&ctx->lock);
+}
+
+static int
+event_sched_in(struct perf_event *event,
+                 struct perf_cpu_context *cpuctx,
+                 struct perf_event_context *ctx,
+                 int cpu)
+{
+        if (event->state <= PERF_EVENT_STATE_OFF)
+                return 0;
+
+        event->state = PERF_EVENT_STATE_ACTIVE;
+        event->oncpu = cpu;     /* TODO: put 'cpu' into cpuctx->cpu */
+        /*
+         * The new state must be visible before we turn it on in the hardware:
+         */
+        smp_wmb();
+
+        if (event->pmu->enable(event)) {
+                event->state = PERF_EVENT_STATE_INACTIVE;
+                event->oncpu = -1;
+                return -EAGAIN;
+        }
+
+        event->tstamp_running += ctx->time - event->tstamp_stopped;
+
+        if (!is_software_event(event))
+                cpuctx->active_oncpu++;
+        ctx->nr_active++;
+
+        if (event->attr.exclusive)
+                cpuctx->exclusive = 1;
+
+        return 0;
+}
+
+static int
+group_sched_in(struct perf_event *group_event,
+               struct perf_cpu_context *cpuctx,
+               struct perf_event_context *ctx,
+               int cpu)
+{
+        struct perf_event *event, *partial_group;
+        int ret;
+
+        if (group_event->state == PERF_EVENT_STATE_OFF)
+                return 0;
+
+        ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu);
+        if (ret)
+                return ret < 0 ? ret : 0;
+
+        if (event_sched_in(group_event, cpuctx, ctx, cpu))
+                return -EAGAIN;
+
+        /*
+         * Schedule in siblings as one group (if any):
+         */
+        list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+                if (event_sched_in(event, cpuctx, ctx, cpu)) {
+                        partial_group = event;
+                        goto group_error;
+                }
+        }
+
+        return 0;
+
+group_error:
+        /*
+         * Groups can be scheduled in as one unit only, so undo any
+         * partial group before returning:
+         */
+        list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+                if (event == partial_group)
+                        break;
+                event_sched_out(event, cpuctx, ctx);
+        }
+        event_sched_out(group_event, cpuctx, ctx);
+
+        return -EAGAIN;
+}
+
+/*
+ * Return 1 for a group consisting entirely of software events,
+ * 0 if the group contains any hardware events.
+ */
+static int is_software_only_group(struct perf_event *leader)
+{
+        struct perf_event *event;
+
+        if (!is_software_event(leader))
+                return 0;
+
+        list_for_each_entry(event, &leader->sibling_list, group_entry)
+                if (!is_software_event(event))
+                        return 0;
+
+        return 1;
+}
+
+/*
+ * Work out whether we can put this event group on the CPU now.
+ */
+static int group_can_go_on(struct perf_event *event,
+                           struct perf_cpu_context *cpuctx,
+                           int can_add_hw)
+{
+        /*
+         * Groups consisting entirely of software events can always go on.
+         */
+        if (is_software_only_group(event))
+                return 1;
+        /*
+         * If an exclusive group is already on, no other hardware
+         * events can go on.
+         */
+        if (cpuctx->exclusive)
+                return 0;
+        /*
+         * If this group is exclusive and there are already
+         * events on the CPU, it can't go on.
+         */
+        if (event->attr.exclusive && cpuctx->active_oncpu)
+                return 0;
+        /*
+         * Otherwise, try to add it if all previous groups were able
+         * to go on.
+         */
+        return can_add_hw;
+}
+
+static void add_event_to_ctx(struct perf_event *event,
+                               struct perf_event_context *ctx)
+{
+        list_add_event(event, ctx);
+        event->tstamp_enabled = ctx->time;
+        event->tstamp_running = ctx->time;
+        event->tstamp_stopped = ctx->time;
+}
+
+/*
+ * Cross CPU call to install and enable a performance event
+ *
+ * Must be called with ctx->mutex held
+ */
+static void __perf_install_in_context(void *info)
+{
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        struct perf_event *event = info;
+        struct perf_event_context *ctx = event->ctx;
+        struct perf_event *leader = event->group_leader;
+        int cpu = smp_processor_id();
+        int err;
+
+        /*
+         * If this is a task context, we need to check whether it is
+         * the current task context of this cpu. If not it has been
+         * scheduled out before the smp call arrived.
+         * Or possibly this is the right context but it isn't
+         * on this cpu because it had no events.
+         */
+        if (ctx->task && cpuctx->task_ctx != ctx) {
+                if (cpuctx->task_ctx || ctx->task != current)
+                        return;
+                cpuctx->task_ctx = ctx;
+        }
+
+        spin_lock(&ctx->lock);
+        ctx->is_active = 1;
+        update_context_time(ctx);
+
+        /*
+         * Protect the list operation against NMI by disabling the
+         * events on a global level. NOP for non NMI based events.
+         */
+        perf_disable();
+
+        add_event_to_ctx(event, ctx);
+
+        /*
+         * Don't put the event on if it is disabled or if
+         * it is in a group and the group isn't on.
+         */
+        if (event->state != PERF_EVENT_STATE_INACTIVE ||
+            (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE))
+                goto unlock;
+
+        /*
+         * An exclusive event can't go on if there are already active
+         * hardware events, and no hardware event can go on if there
+         * is already an exclusive event on.
+         */
+        if (!group_can_go_on(event, cpuctx, 1))
+                err = -EEXIST;
+        else
+                err = event_sched_in(event, cpuctx, ctx, cpu);
+
+        if (err) {
+                /*
+                 * This event couldn't go on.  If it is in a group
+                 * then we have to pull the whole group off.
+                 * If the event group is pinned then put it in error state.
+                 */
+                if (leader != event)
+                        group_sched_out(leader, cpuctx, ctx);
+                if (leader->attr.pinned) {
+                        update_group_times(leader);
+                        leader->state = PERF_EVENT_STATE_ERROR;
+                }
+        }
+
+        if (!err && !ctx->task && cpuctx->max_pertask)
+                cpuctx->max_pertask--;
+
+ unlock:
+        perf_enable();
+
+        spin_unlock(&ctx->lock);
+}
+
+/*
+ * Attach a performance event to a context
+ *
+ * First we add the event to the list with the hardware enable bit
+ * in event->hw_config cleared.
+ *
+ * If the event is attached to a task which is on a CPU we use a smp
+ * call to enable it in the task context. The task might have been
+ * scheduled away, but we check this in the smp call again.
+ *
+ * Must be called with ctx->mutex held.
+ */
+static void
+perf_install_in_context(struct perf_event_context *ctx,
+                        struct perf_event *event,
+                        int cpu)
+{
+        struct task_struct *task = ctx->task;
+
+        if (!task) {
+                /*
+                 * Per cpu events are installed via an smp call and
+                 * the install is always sucessful.
+                 */
+                smp_call_function_single(cpu, __perf_install_in_context,
+                                         event, 1);
+                return;
+        }
+
+retry:
+        task_oncpu_function_call(task, __perf_install_in_context,
+                                 event);
+
+        spin_lock_irq(&ctx->lock);
+        /*
+         * we need to retry the smp call.
+         */
+        if (ctx->is_active && list_empty(&event->group_entry)) {
+                spin_unlock_irq(&ctx->lock);
+                goto retry;
+        }
+
+        /*
+         * The lock prevents that this context is scheduled in so we
+         * can add the event safely, if it the call above did not
+         * succeed.
+         */
+        if (list_empty(&event->group_entry))
+                add_event_to_ctx(event, ctx);
+        spin_unlock_irq(&ctx->lock);
+}
+
+/*
+ * Put a event into inactive state and update time fields.
+ * Enabling the leader of a group effectively enables all
+ * the group members that aren't explicitly disabled, so we
+ * have to update their ->tstamp_enabled also.
+ * Note: this works for group members as well as group leaders
+ * since the non-leader members' sibling_lists will be empty.
+ */
+static void __perf_event_mark_enabled(struct perf_event *event,
+                                        struct perf_event_context *ctx)
+{
+        struct perf_event *sub;
+
+        event->state = PERF_EVENT_STATE_INACTIVE;
+        event->tstamp_enabled = ctx->time - event->total_time_enabled;
+        list_for_each_entry(sub, &event->sibling_list, group_entry)
+                if (sub->state >= PERF_EVENT_STATE_INACTIVE)
+                        sub->tstamp_enabled =
+                                ctx->time - sub->total_time_enabled;
+}
+
+/*
+ * Cross CPU call to enable a performance event
+ */
+static void __perf_event_enable(void *info)
+{
+        struct perf_event *event = info;
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        struct perf_event_context *ctx = event->ctx;
+        struct perf_event *leader = event->group_leader;
+        int err;
+
+        /*
+         * If this is a per-task event, need to check whether this
+         * event's task is the current task on this cpu.
+         */
+        if (ctx->task && cpuctx->task_ctx != ctx) {
+                if (cpuctx->task_ctx || ctx->task != current)
+                        return;
+                cpuctx->task_ctx = ctx;
+        }
+
+        spin_lock(&ctx->lock);
+        ctx->is_active = 1;
+        update_context_time(ctx);
+
+        if (event->state >= PERF_EVENT_STATE_INACTIVE)
+                goto unlock;
+        __perf_event_mark_enabled(event, ctx);
+
+        /*
+         * If the event is in a group and isn't the group leader,
+         * then don't put it on unless the group is on.
+         */
+        if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
+                goto unlock;
+
+        if (!group_can_go_on(event, cpuctx, 1)) {
+                err = -EEXIST;
+        } else {
+                perf_disable();
+                if (event == leader)
+                        err = group_sched_in(event, cpuctx, ctx,
+                                             smp_processor_id());
+                else
+                        err = event_sched_in(event, cpuctx, ctx,
+                                               smp_processor_id());
+                perf_enable();
+        }
+
+        if (err) {
+                /*
+                 * If this event can't go on and it's part of a
+                 * group, then the whole group has to come off.
+                 */
+                if (leader != event)
+                        group_sched_out(leader, cpuctx, ctx);
+                if (leader->attr.pinned) {
+                        update_group_times(leader);
+                        leader->state = PERF_EVENT_STATE_ERROR;
+                }
+        }
+
+ unlock:
+        spin_unlock(&ctx->lock);
+}
+
+/*
+ * Enable a event.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This condition is satisfied when called through
+ * perf_event_for_each_child or perf_event_for_each as described
+ * for perf_event_disable.
+ */
+static void perf_event_enable(struct perf_event *event)
+{
+        struct perf_event_context *ctx = event->ctx;
+        struct task_struct *task = ctx->task;
+
+        if (!task) {
+                /*
+                 * Enable the event on the cpu that it's on
+                 */
+                smp_call_function_single(event->cpu, __perf_event_enable,
+                                         event, 1);
+                return;
+        }
+
+        spin_lock_irq(&ctx->lock);
+        if (event->state >= PERF_EVENT_STATE_INACTIVE)
+                goto out;
+
+        /*
+         * If the event is in error state, clear that first.
+         * That way, if we see the event in error state below, we
+         * know that it has gone back into error state, as distinct
+         * from the task having been scheduled away before the
+         * cross-call arrived.
+         */
+        if (event->state == PERF_EVENT_STATE_ERROR)
+                event->state = PERF_EVENT_STATE_OFF;
+
+ retry:
+        spin_unlock_irq(&ctx->lock);
+        task_oncpu_function_call(task, __perf_event_enable, event);
+
+        spin_lock_irq(&ctx->lock);
+
+        /*
+         * If the context is active and the event is still off,
+         * we need to retry the cross-call.
+         */
+        if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF)
+                goto retry;
+
+        /*
+         * Since we have the lock this context can't be scheduled
+         * in, so we can change the state safely.
+         */
+        if (event->state == PERF_EVENT_STATE_OFF)
+                __perf_event_mark_enabled(event, ctx);
+
+ out:
+        spin_unlock_irq(&ctx->lock);
+}
+
+static int perf_event_refresh(struct perf_event *event, int refresh)
+{
+        /*
+         * not supported on inherited events
+         */
+        if (event->attr.inherit)
+                return -EINVAL;
+
+        atomic_add(refresh, &event->event_limit);
+        perf_event_enable(event);
+
+        return 0;
+}
+
+void __perf_event_sched_out(struct perf_event_context *ctx,
+                              struct perf_cpu_context *cpuctx)
+{
+        struct perf_event *event;
+
+        spin_lock(&ctx->lock);
+        ctx->is_active = 0;
+        if (likely(!ctx->nr_events))
+                goto out;
+        update_context_time(ctx);
+
+        perf_disable();
+        if (ctx->nr_active)
+                list_for_each_entry(event, &ctx->group_list, group_entry)
+                        group_sched_out(event, cpuctx, ctx);
+
+        perf_enable();
+ out:
+        spin_unlock(&ctx->lock);
+}
+
+/*
+ * Test whether two contexts are equivalent, i.e. whether they
+ * have both been cloned from the same version of the same context
+ * and they both have the same number of enabled events.
+ * If the number of enabled events is the same, then the set
+ * of enabled events should be the same, because these are both
+ * inherited contexts, therefore we can't access individual events
+ * in them directly with an fd; we can only enable/disable all
+ * events via prctl, or enable/disable all events in a family
+ * via ioctl, which will have the same effect on both contexts.
+ */
+static int context_equiv(struct perf_event_context *ctx1,
+                         struct perf_event_context *ctx2)
+{
+        return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
+                && ctx1->parent_gen == ctx2->parent_gen
+                && !ctx1->pin_count && !ctx2->pin_count;
+}
+
+static void __perf_event_read(void *event);
+
+static void __perf_event_sync_stat(struct perf_event *event,
+                                     struct perf_event *next_event)
+{
+        u64 value;
+
+        if (!event->attr.inherit_stat)
+                return;
+
+        /*
+         * Update the event value, we cannot use perf_event_read()
+         * because we're in the middle of a context switch and have IRQs
+         * disabled, which upsets smp_call_function_single(), however
+         * we know the event must be on the current CPU, therefore we
+         * don't need to use it.
+         */
+        switch (event->state) {
+        case PERF_EVENT_STATE_ACTIVE:
+                __perf_event_read(event);
+                break;
+
+        case PERF_EVENT_STATE_INACTIVE:
+                update_event_times(event);
+                break;
+
+        default:
+                break;
+        }
+
+        /*
+         * In order to keep per-task stats reliable we need to flip the event
+         * values when we flip the contexts.
+         */
+        value = atomic64_read(&next_event->count);
+        value = atomic64_xchg(&event->count, value);
+        atomic64_set(&next_event->count, value);
+
+        swap(event->total_time_enabled, next_event->total_time_enabled);
+        swap(event->total_time_running, next_event->total_time_running);
+
+        /*
+         * Since we swizzled the values, update the user visible data too.
+         */
+        perf_event_update_userpage(event);
+        perf_event_update_userpage(next_event);
+}
+
+#define list_next_entry(pos, member) \
+        list_entry(pos->member.next, typeof(*pos), member)
+
+static void perf_event_sync_stat(struct perf_event_context *ctx,
+                                   struct perf_event_context *next_ctx)
+{
+        struct perf_event *event, *next_event;
+
+        if (!ctx->nr_stat)
+                return;
+
+        event = list_first_entry(&ctx->event_list,
+                                   struct perf_event, event_entry);
+
+        next_event = list_first_entry(&next_ctx->event_list,
+                                        struct perf_event, event_entry);
+
+        while (&event->event_entry != &ctx->event_list &&
+               &next_event->event_entry != &next_ctx->event_list) {
+
+                __perf_event_sync_stat(event, next_event);
+
+                event = list_next_entry(event, event_entry);
+                next_event = list_next_entry(next_event, event_entry);
+        }
+}
+
+/*
+ * Called from scheduler to remove the events of the current task,
+ * with interrupts disabled.
+ *
+ * We stop each event and update the event value in event->count.
+ *
+ * This does not protect us against NMI, but disable()
+ * sets the disabled bit in the control field of event _before_
+ * accessing the event control register. If a NMI hits, then it will
+ * not restart the event.
+ */
+void perf_event_task_sched_out(struct task_struct *task,
+                                 struct task_struct *next, int cpu)
+{
+        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+        struct perf_event_context *ctx = task->perf_event_ctxp;
+        struct perf_event_context *next_ctx;
+        struct perf_event_context *parent;
+        struct pt_regs *regs;
+        int do_switch = 1;
+
+        regs = task_pt_regs(task);
+        perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
+
+        if (likely(!ctx || !cpuctx->task_ctx))
+                return;
+
+        update_context_time(ctx);
+
+        rcu_read_lock();
+        parent = rcu_dereference(ctx->parent_ctx);
+        next_ctx = next->perf_event_ctxp;
+        if (parent && next_ctx &&
+            rcu_dereference(next_ctx->parent_ctx) == parent) {
+                /*
+                 * Looks like the two contexts are clones, so we might be
+                 * able to optimize the context switch.  We lock both
+                 * contexts and check that they are clones under the
+                 * lock (including re-checking that neither has been
+                 * uncloned in the meantime).  It doesn't matter which
+                 * order we take the locks because no other cpu could
+                 * be trying to lock both of these tasks.
+                 */
+                spin_lock(&ctx->lock);
+                spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
+                if (context_equiv(ctx, next_ctx)) {
+                        /*
+                         * XXX do we need a memory barrier of sorts
+                         * wrt to rcu_dereference() of perf_event_ctxp
+                         */
+                        task->perf_event_ctxp = next_ctx;
+                        next->perf_event_ctxp = ctx;
+                        ctx->task = next;
+                        next_ctx->task = task;
+                        do_switch = 0;
+
+                        perf_event_sync_stat(ctx, next_ctx);
+                }
+                spin_unlock(&next_ctx->lock);
+                spin_unlock(&ctx->lock);
+        }
+        rcu_read_unlock();
+
+        if (do_switch) {
+                __perf_event_sched_out(ctx, cpuctx);
+                cpuctx->task_ctx = NULL;
+        }
+}
+
+/*
+ * Called with IRQs disabled
+ */
+static void __perf_event_task_sched_out(struct perf_event_context *ctx)
+{
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+
+        if (!cpuctx->task_ctx)
+                return;
+
+        if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
+                return;
+
+        __perf_event_sched_out(ctx, cpuctx);
+        cpuctx->task_ctx = NULL;
+}
+
+/*
+ * Called with IRQs disabled
+ */
+static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx)
+{
+        __perf_event_sched_out(&cpuctx->ctx, cpuctx);
+}
+
+static void
+__perf_event_sched_in(struct perf_event_context *ctx,
+                        struct perf_cpu_context *cpuctx, int cpu)
+{
+        struct perf_event *event;
+        int can_add_hw = 1;
+
+        spin_lock(&ctx->lock);
+        ctx->is_active = 1;
+        if (likely(!ctx->nr_events))
+                goto out;
+
+        ctx->timestamp = perf_clock();
+
+        perf_disable();
+
+        /*
+         * First go through the list and put on any pinned groups
+         * in order to give them the best chance of going on.
+         */
+        list_for_each_entry(event, &ctx->group_list, group_entry) {
+                if (event->state <= PERF_EVENT_STATE_OFF ||
+                    !event->attr.pinned)
+                        continue;
+                if (event->cpu != -1 && event->cpu != cpu)
+                        continue;
+
+                if (group_can_go_on(event, cpuctx, 1))
+                        group_sched_in(event, cpuctx, ctx, cpu);
+
+                /*
+                 * If this pinned group hasn't been scheduled,
+                 * put it in error state.
+                 */
+                if (event->state == PERF_EVENT_STATE_INACTIVE) {
+                        update_group_times(event);
+                        event->state = PERF_EVENT_STATE_ERROR;
+                }
+        }
+
+        list_for_each_entry(event, &ctx->group_list, group_entry) {
+                /*
+                 * Ignore events in OFF or ERROR state, and
+                 * ignore pinned events since we did them already.
+                 */
+                if (event->state <= PERF_EVENT_STATE_OFF ||
+                    event->attr.pinned)
+                        continue;
+
+                /*
+                 * Listen to the 'cpu' scheduling filter constraint
+                 * of events:
+                 */
+                if (event->cpu != -1 && event->cpu != cpu)
+                        continue;
+
+                if (group_can_go_on(event, cpuctx, can_add_hw))
+                        if (group_sched_in(event, cpuctx, ctx, cpu))
+                                can_add_hw = 0;
+        }
+        perf_enable();
+ out:
+        spin_unlock(&ctx->lock);
+}
+
+/*
+ * Called from scheduler to add the events of the current task
+ * with interrupts disabled.
+ *
+ * We restore the event value and then enable it.
+ *
+ * This does not protect us against NMI, but enable()
+ * sets the enabled bit in the control field of event _before_
+ * accessing the event control register. If a NMI hits, then it will
+ * keep the event running.
+ */
+void perf_event_task_sched_in(struct task_struct *task, int cpu)
+{
+        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+        struct perf_event_context *ctx = task->perf_event_ctxp;
+
+        if (likely(!ctx))
+                return;
+        if (cpuctx->task_ctx == ctx)
+                return;
+        __perf_event_sched_in(ctx, cpuctx, cpu);
+        cpuctx->task_ctx = ctx;
+}
+
+static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
+{
+        struct perf_event_context *ctx = &cpuctx->ctx;
+
+        __perf_event_sched_in(ctx, cpuctx, cpu);
+}
+
+#define MAX_INTERRUPTS (~0ULL)
+
+static void perf_log_throttle(struct perf_event *event, int enable);
+
+static void perf_adjust_period(struct perf_event *event, u64 events)
+{
+        struct hw_perf_event *hwc = &event->hw;
+        u64 period, sample_period;
+        s64 delta;
+
+        events *= hwc->sample_period;
+        period = div64_u64(events, event->attr.sample_freq);
+
+        delta = (s64)(period - hwc->sample_period);
+        delta = (delta + 7) / 8; /* low pass filter */
+
+        sample_period = hwc->sample_period + delta;
+
+        if (!sample_period)
+                sample_period = 1;
+
+        hwc->sample_period = sample_period;
+}
+
+static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
+{
+        struct perf_event *event;
+        struct hw_perf_event *hwc;
+        u64 interrupts, freq;
+
+        spin_lock(&ctx->lock);
+        list_for_each_entry(event, &ctx->group_list, group_entry) {
+                if (event->state != PERF_EVENT_STATE_ACTIVE)
+                        continue;
+
+                hwc = &event->hw;
+
+                interrupts = hwc->interrupts;
+                hwc->interrupts = 0;
+
+                /*
+                 * unthrottle events on the tick
+                 */
+                if (interrupts == MAX_INTERRUPTS) {
+                        perf_log_throttle(event, 1);
+                        event->pmu->unthrottle(event);
+                        interrupts = 2*sysctl_perf_event_sample_rate/HZ;
+                }
+
+                if (!event->attr.freq || !event->attr.sample_freq)
+                        continue;
+
+                /*
+                 * if the specified freq < HZ then we need to skip ticks
+                 */
+                if (event->attr.sample_freq < HZ) {
+                        freq = event->attr.sample_freq;
+
+                        hwc->freq_count += freq;
+                        hwc->freq_interrupts += interrupts;
+
+                        if (hwc->freq_count < HZ)
+                                continue;
+
+                        interrupts = hwc->freq_interrupts;
+                        hwc->freq_interrupts = 0;
+                        hwc->freq_count -= HZ;
+                } else
+                        freq = HZ;
+
+                perf_adjust_period(event, freq * interrupts);
+
+                /*
+                 * In order to avoid being stalled by an (accidental) huge
+                 * sample period, force reset the sample period if we didn't
+                 * get any events in this freq period.
+                 */
+                if (!interrupts) {
+                        perf_disable();
+                        event->pmu->disable(event);
+                        atomic64_set(&hwc->period_left, 0);
+                        event->pmu->enable(event);
+                        perf_enable();
+                }
+        }
+        spin_unlock(&ctx->lock);
+}
+
+/*
+ * Round-robin a context's events:
+ */
+static void rotate_ctx(struct perf_event_context *ctx)
+{
+        struct perf_event *event;
+
+        if (!ctx->nr_events)
+                return;
+
+        spin_lock(&ctx->lock);
+        /*
+         * Rotate the first entry last (works just fine for group events too):
+         */
+        perf_disable();
+        list_for_each_entry(event, &ctx->group_list, group_entry) {
+                list_move_tail(&event->group_entry, &ctx->group_list);
+                break;
+        }
+        perf_enable();
+
+        spin_unlock(&ctx->lock);
+}
+
+void perf_event_task_tick(struct task_struct *curr, int cpu)
+{
+        struct perf_cpu_context *cpuctx;
+        struct perf_event_context *ctx;
+
+        if (!atomic_read(&nr_events))
+                return;
+
+        cpuctx = &per_cpu(perf_cpu_context, cpu);
+        ctx = curr->perf_event_ctxp;
+
+        perf_ctx_adjust_freq(&cpuctx->ctx);
+        if (ctx)
+                perf_ctx_adjust_freq(ctx);
+
+        perf_event_cpu_sched_out(cpuctx);
+        if (ctx)
+                __perf_event_task_sched_out(ctx);
+
+        rotate_ctx(&cpuctx->ctx);
+        if (ctx)
+                rotate_ctx(ctx);
+
+        perf_event_cpu_sched_in(cpuctx, cpu);
+        if (ctx)
+                perf_event_task_sched_in(curr, cpu);
+}
+
+/*
+ * Enable all of a task's events that have been marked enable-on-exec.
+ * This expects task == current.
+ */
+static void perf_event_enable_on_exec(struct task_struct *task)
+{
+        struct perf_event_context *ctx;
+        struct perf_event *event;
+        unsigned long flags;
+        int enabled = 0;
+
+        local_irq_save(flags);
+        ctx = task->perf_event_ctxp;
+        if (!ctx || !ctx->nr_events)
+                goto out;
+
+        __perf_event_task_sched_out(ctx);
+
+        spin_lock(&ctx->lock);
+
+        list_for_each_entry(event, &ctx->group_list, group_entry) {
+                if (!event->attr.enable_on_exec)
+                        continue;
+                event->attr.enable_on_exec = 0;
+                if (event->state >= PERF_EVENT_STATE_INACTIVE)
+                        continue;
+                __perf_event_mark_enabled(event, ctx);
+                enabled = 1;
+        }
+
+        /*
+         * Unclone this context if we enabled any event.
+         */
+        if (enabled)
+                unclone_ctx(ctx);
+
+        spin_unlock(&ctx->lock);
+
+        perf_event_task_sched_in(task, smp_processor_id());
+ out:
+        local_irq_restore(flags);
+}
+
+/*
+ * Cross CPU call to read the hardware event
+ */
+static void __perf_event_read(void *info)
+{
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        struct perf_event *event = info;
+        struct perf_event_context *ctx = event->ctx;
+        unsigned long flags;
+
+        /*
+         * If this is a task context, we need to check whether it is
+         * the current task context of this cpu.  If not it has been
+         * scheduled out before the smp call arrived.  In that case
+         * event->count would have been updated to a recent sample
+         * when the event was scheduled out.
+         */
+        if (ctx->task && cpuctx->task_ctx != ctx)
+                return;
+
+        local_irq_save(flags);
+        if (ctx->is_active)
+                update_context_time(ctx);
+        event->pmu->read(event);
+        update_event_times(event);
+        local_irq_restore(flags);
+}
+
+static u64 perf_event_read(struct perf_event *event)
+{
+        /*
+         * If event is enabled and currently active on a CPU, update the
+         * value in the event structure:
+         */
+        if (event->state == PERF_EVENT_STATE_ACTIVE) {
+                smp_call_function_single(event->oncpu,
+                                         __perf_event_read, event, 1);
+        } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
+                update_event_times(event);
+        }
+
+        return atomic64_read(&event->count);
+}
+
+/*
+ * Initialize the perf_event context in a task_struct:
+ */
+static void
+__perf_event_init_context(struct perf_event_context *ctx,
+                            struct task_struct *task)
+{
+        memset(ctx, 0, sizeof(*ctx));
+        spin_lock_init(&ctx->lock);
+        mutex_init(&ctx->mutex);
+        INIT_LIST_HEAD(&ctx->group_list);
+        INIT_LIST_HEAD(&ctx->event_list);
+        atomic_set(&ctx->refcount, 1);
+        ctx->task = task;
+}
+
+static struct perf_event_context *find_get_context(pid_t pid, int cpu)
+{
+        struct perf_event_context *ctx;
+        struct perf_cpu_context *cpuctx;
+        struct task_struct *task;
+        unsigned long flags;
+        int err;
+
+        /*
+         * If cpu is not a wildcard then this is a percpu event:
+         */
+        if (cpu != -1) {
+                /* Must be root to operate on a CPU event: */
+                if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+                        return ERR_PTR(-EACCES);
+
+                if (cpu < 0 || cpu > num_possible_cpus())
+                        return ERR_PTR(-EINVAL);
+
+                /*
+                 * We could be clever and allow to attach a event to an
+                 * offline CPU and activate it when the CPU comes up, but
+                 * that's for later.
+                 */
+                if (!cpu_isset(cpu, cpu_online_map))
+                        return ERR_PTR(-ENODEV);
+
+                cpuctx = &per_cpu(perf_cpu_context, cpu);
+                ctx = &cpuctx->ctx;
+                get_ctx(ctx);
+
+                return ctx;
+        }
+
+        rcu_read_lock();
+        if (!pid)
+                task = current;
+        else
+                task = find_task_by_vpid(pid);
+        if (task)
+                get_task_struct(task);
+        rcu_read_unlock();
+
+        if (!task)
+                return ERR_PTR(-ESRCH);
+
+        /*
+         * Can't attach events to a dying task.
+         */
+        err = -ESRCH;
+        if (task->flags & PF_EXITING)
+                goto errout;
+
+        /* Reuse ptrace permission checks for now. */
+        err = -EACCES;
+        if (!ptrace_may_access(task, PTRACE_MODE_READ))
+                goto errout;
+
+ retry:
+        ctx = perf_lock_task_context(task, &flags);
+        if (ctx) {
+                unclone_ctx(ctx);
+                spin_unlock_irqrestore(&ctx->lock, flags);
+        }
+
+        if (!ctx) {
+                ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL);
+                err = -ENOMEM;
+                if (!ctx)
+                        goto errout;
+                __perf_event_init_context(ctx, task);
+                get_ctx(ctx);
+                if (cmpxchg(&task->perf_event_ctxp, NULL, ctx)) {
+                        /*
+                         * We raced with some other task; use
+                         * the context they set.
+                         */
+                        kfree(ctx);
+                        goto retry;
+                }
+                get_task_struct(task);
+        }
+
+        put_task_struct(task);
+        return ctx;
+
+ errout:
+        put_task_struct(task);
+        return ERR_PTR(err);
+}
+
+static void free_event_rcu(struct rcu_head *head)
+{
+        struct perf_event *event;
+
+        event = container_of(head, struct perf_event, rcu_head);
+        if (event->ns)
+                put_pid_ns(event->ns);
+        kfree(event);
+}
+
+static void perf_pending_sync(struct perf_event *event);
+
+static void free_event(struct perf_event *event)
+{
+        perf_pending_sync(event);
+
+        if (!event->parent) {
+                atomic_dec(&nr_events);
+                if (event->attr.mmap)
+                        atomic_dec(&nr_mmap_events);
+                if (event->attr.comm)
+                        atomic_dec(&nr_comm_events);
+                if (event->attr.task)
+                        atomic_dec(&nr_task_events);
+        }
+
+        if (event->output) {
+                fput(event->output->filp);
+                event->output = NULL;
+        }
+
+        if (event->destroy)
+                event->destroy(event);
+
+        put_ctx(event->ctx);
+        call_rcu(&event->rcu_head, free_event_rcu);
+}
+
+/*
+ * Called when the last reference to the file is gone.
+ */
+static int perf_release(struct inode *inode, struct file *file)
+{
+        struct perf_event *event = file->private_data;
+        struct perf_event_context *ctx = event->ctx;
+
+        file->private_data = NULL;
+
+        WARN_ON_ONCE(ctx->parent_ctx);
+        mutex_lock(&ctx->mutex);
+        perf_event_remove_from_context(event);
+        mutex_unlock(&ctx->mutex);
+
+        mutex_lock(&event->owner->perf_event_mutex);
+        list_del_init(&event->owner_entry);
+        mutex_unlock(&event->owner->perf_event_mutex);
+        put_task_struct(event->owner);
+
+        free_event(event);
+
+        return 0;
+}
+
+static int perf_event_read_size(struct perf_event *event)
+{
+        int entry = sizeof(u64); /* value */
+        int size = 0;
+        int nr = 1;
+
+        if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+                size += sizeof(u64);
+
+        if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+                size += sizeof(u64);
+
+        if (event->attr.read_format & PERF_FORMAT_ID)
+                entry += sizeof(u64);
+
+        if (event->attr.read_format & PERF_FORMAT_GROUP) {
+                nr += event->group_leader->nr_siblings;
+                size += sizeof(u64);
+        }
+
+        size += entry * nr;
+
+        return size;
+}
+
+static u64 perf_event_read_value(struct perf_event *event)
+{
+        struct perf_event *child;
+        u64 total = 0;
+
+        total += perf_event_read(event);
+        list_for_each_entry(child, &event->child_list, child_list)
+                total += perf_event_read(child);
+
+        return total;
+}
+
+static int perf_event_read_entry(struct perf_event *event,
+                                   u64 read_format, char __user *buf)
+{
+        int n = 0, count = 0;
+        u64 values[2];
+
+        values[n++] = perf_event_read_value(event);
+        if (read_format & PERF_FORMAT_ID)
+                values[n++] = primary_event_id(event);
+
+        count = n * sizeof(u64);
+
+        if (copy_to_user(buf, values, count))
+                return -EFAULT;
+
+        return count;
+}
+
+static int perf_event_read_group(struct perf_event *event,
+                                   u64 read_format, char __user *buf)
+{
+        struct perf_event *leader = event->group_leader, *sub;
+        int n = 0, size = 0, err = -EFAULT;
+        u64 values[3];
+
+        values[n++] = 1 + leader->nr_siblings;
+        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+                values[n++] = leader->total_time_enabled +
+                        atomic64_read(&leader->child_total_time_enabled);
+        }
+        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+                values[n++] = leader->total_time_running +
+                        atomic64_read(&leader->child_total_time_running);
+        }
+
+        size = n * sizeof(u64);
+
+        if (copy_to_user(buf, values, size))
+                return -EFAULT;
+
+        err = perf_event_read_entry(leader, read_format, buf + size);
+        if (err < 0)
+                return err;
+
+        size += err;
+
+        list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+                err = perf_event_read_entry(sub, read_format,
+                                buf + size);
+                if (err < 0)
+                        return err;
+
+                size += err;
+        }
+
+        return size;
+}
+
+static int perf_event_read_one(struct perf_event *event,
+                                 u64 read_format, char __user *buf)
+{
+        u64 values[4];
+        int n = 0;
+
+        values[n++] = perf_event_read_value(event);
+        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+                values[n++] = event->total_time_enabled +
+                        atomic64_read(&event->child_total_time_enabled);
+        }
+        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+                values[n++] = event->total_time_running +
+                        atomic64_read(&event->child_total_time_running);
+        }
+        if (read_format & PERF_FORMAT_ID)
+                values[n++] = primary_event_id(event);
+
+        if (copy_to_user(buf, values, n * sizeof(u64)))
+                return -EFAULT;
+
+        return n * sizeof(u64);
+}
+
+/*
+ * Read the performance event - simple non blocking version for now
+ */
+static ssize_t
+perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
+{
+        u64 read_format = event->attr.read_format;
+        int ret;
+
+        /*
+         * Return end-of-file for a read on a event that is in
+         * error state (i.e. because it was pinned but it couldn't be
+         * scheduled on to the CPU at some point).
+         */
+        if (event->state == PERF_EVENT_STATE_ERROR)
+                return 0;
+
+        if (count < perf_event_read_size(event))
+                return -ENOSPC;
+
+        WARN_ON_ONCE(event->ctx->parent_ctx);
+        mutex_lock(&event->child_mutex);
+        if (read_format & PERF_FORMAT_GROUP)
+                ret = perf_event_read_group(event, read_format, buf);
+        else
+                ret = perf_event_read_one(event, read_format, buf);
+        mutex_unlock(&event->child_mutex);
+
+        return ret;
+}
+
+static ssize_t
+perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+        struct perf_event *event = file->private_data;
+
+        return perf_read_hw(event, buf, count);
+}
+
+static unsigned int perf_poll(struct file *file, poll_table *wait)
+{
+        struct perf_event *event = file->private_data;
+        struct perf_mmap_data *data;
+        unsigned int events = POLL_HUP;
+
+        rcu_read_lock();
+        data = rcu_dereference(event->data);
+        if (data)
+                events = atomic_xchg(&data->poll, 0);
+        rcu_read_unlock();
+
+        poll_wait(file, &event->waitq, wait);
+
+        return events;
+}
+
+static void perf_event_reset(struct perf_event *event)
+{
+        (void)perf_event_read(event);
+        atomic64_set(&event->count, 0);
+        perf_event_update_userpage(event);
+}
+
+/*
+ * Holding the top-level event's child_mutex means that any
+ * descendant process that has inherited this event will block
+ * in sync_child_event if it goes to exit, thus satisfying the
+ * task existence requirements of perf_event_enable/disable.
+ */
+static void perf_event_for_each_child(struct perf_event *event,
+                                        void (*func)(struct perf_event *))
+{
+        struct perf_event *child;
+
+        WARN_ON_ONCE(event->ctx->parent_ctx);
+        mutex_lock(&event->child_mutex);
+        func(event);
+        list_for_each_entry(child, &event->child_list, child_list)
+                func(child);
+        mutex_unlock(&event->child_mutex);
+}
+
+static void perf_event_for_each(struct perf_event *event,
+                                  void (*func)(struct perf_event *))
+{
+        struct perf_event_context *ctx = event->ctx;
+        struct perf_event *sibling;
+
+        WARN_ON_ONCE(ctx->parent_ctx);
+        mutex_lock(&ctx->mutex);
+        event = event->group_leader;
+
+        perf_event_for_each_child(event, func);
+        func(event);
+        list_for_each_entry(sibling, &event->sibling_list, group_entry)
+                perf_event_for_each_child(event, func);
+        mutex_unlock(&ctx->mutex);
+}
+
+static int perf_event_period(struct perf_event *event, u64 __user *arg)
+{
+        struct perf_event_context *ctx = event->ctx;
+        unsigned long size;
+        int ret = 0;
+        u64 value;
+
+        if (!event->attr.sample_period)
+                return -EINVAL;
+
+        size = copy_from_user(&value, arg, sizeof(value));
+        if (size != sizeof(value))
+                return -EFAULT;
+
+        if (!value)
+                return -EINVAL;
+
+        spin_lock_irq(&ctx->lock);
+        if (event->attr.freq) {
+                if (value > sysctl_perf_event_sample_rate) {
+                        ret = -EINVAL;
+                        goto unlock;
+                }
+
+                event->attr.sample_freq = value;
+        } else {
+                event->attr.sample_period = value;
+                event->hw.sample_period = value;
+        }
+unlock:
+        spin_unlock_irq(&ctx->lock);
+
+        return ret;
+}
+
+int perf_event_set_output(struct perf_event *event, int output_fd);
+
+static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+        struct perf_event *event = file->private_data;
+        void (*func)(struct perf_event *);
+        u32 flags = arg;
+
+        switch (cmd) {
+        case PERF_EVENT_IOC_ENABLE:
+                func = perf_event_enable;
+                break;
+        case PERF_EVENT_IOC_DISABLE:
+                func = perf_event_disable;
+                break;
+        case PERF_EVENT_IOC_RESET:
+                func = perf_event_reset;
+                break;
+
+        case PERF_EVENT_IOC_REFRESH:
+                return perf_event_refresh(event, arg);
+
+        case PERF_EVENT_IOC_PERIOD:
+                return perf_event_period(event, (u64 __user *)arg);
+
+        case PERF_EVENT_IOC_SET_OUTPUT:
+                return perf_event_set_output(event, arg);
+
+        default:
+                return -ENOTTY;
+        }
+
+        if (flags & PERF_IOC_FLAG_GROUP)
+                perf_event_for_each(event, func);
+        else
+                perf_event_for_each_child(event, func);
+
+        return 0;
+}
+
+int perf_event_task_enable(void)
+{
+        struct perf_event *event;
+
+        mutex_lock(&current->perf_event_mutex);
+        list_for_each_entry(event, &current->perf_event_list, owner_entry)
+                perf_event_for_each_child(event, perf_event_enable);
+        mutex_unlock(&current->perf_event_mutex);
+
+        return 0;
+}
+
+int perf_event_task_disable(void)
+{
+        struct perf_event *event;
+
+        mutex_lock(&current->perf_event_mutex);
+        list_for_each_entry(event, &current->perf_event_list, owner_entry)
+                perf_event_for_each_child(event, perf_event_disable);
+        mutex_unlock(&current->perf_event_mutex);
+
+        return 0;
+}
+
+#ifndef PERF_EVENT_INDEX_OFFSET
+# define PERF_EVENT_INDEX_OFFSET 0
+#endif
+
+static int perf_event_index(struct perf_event *event)
+{
+        if (event->state != PERF_EVENT_STATE_ACTIVE)
+                return 0;
+
+        return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET;
+}
+
+/*
+ * Callers need to ensure there can be no nesting of this function, otherwise
+ * the seqlock logic goes bad. We can not serialize this because the arch
+ * code calls this from NMI context.
+ */
+void perf_event_update_userpage(struct perf_event *event)
+{
+        struct perf_event_mmap_page *userpg;
+        struct perf_mmap_data *data;
+
+        rcu_read_lock();
+        data = rcu_dereference(event->data);
+        if (!data)
+                goto unlock;
+
+        userpg = data->user_page;
+
+        /*
+         * Disable preemption so as to not let the corresponding user-space
+         * spin too long if we get preempted.
+         */
+        preempt_disable();
+        ++userpg->lock;
+        barrier();
+        userpg->index = perf_event_index(event);
+        userpg->offset = atomic64_read(&event->count);
+        if (event->state == PERF_EVENT_STATE_ACTIVE)
+                userpg->offset -= atomic64_read(&event->hw.prev_count);
+
+        userpg->time_enabled = event->total_time_enabled +
+                        atomic64_read(&event->child_total_time_enabled);
+
+        userpg->time_running = event->total_time_running +
+                        atomic64_read(&event->child_total_time_running);
+
+        barrier();
+        ++userpg->lock;
+        preempt_enable();
+unlock:
+        rcu_read_unlock();
+}
+
+static unsigned long perf_data_size(struct perf_mmap_data *data)
+{
+        return data->nr_pages << (PAGE_SHIFT + data->data_order);
+}
+
+#ifndef CONFIG_PERF_USE_VMALLOC
+
+/*
+ * Back perf_mmap() with regular GFP_KERNEL-0 pages.
+ */
+
+static struct page *
+perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff)
+{
+        if (pgoff > data->nr_pages)
+                return NULL;
+
+        if (pgoff == 0)
+                return virt_to_page(data->user_page);
+
+        return virt_to_page(data->data_pages[pgoff - 1]);
+}
+
+static struct perf_mmap_data *
+perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
+{
+        struct perf_mmap_data *data;
+        unsigned long size;
+        int i;
+
+        WARN_ON(atomic_read(&event->mmap_count));
+
+        size = sizeof(struct perf_mmap_data);
+        size += nr_pages * sizeof(void *);
+
+        data = kzalloc(size, GFP_KERNEL);
+        if (!data)
+                goto fail;
+
+        data->user_page = (void *)get_zeroed_page(GFP_KERNEL);
+        if (!data->user_page)
+                goto fail_user_page;
+
+        for (i = 0; i < nr_pages; i++) {
+                data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
+                if (!data->data_pages[i])
+                        goto fail_data_pages;
+        }
+
+        data->data_order = 0;
+        data->nr_pages = nr_pages;
+
+        return data;
+
+fail_data_pages:
+        for (i--; i >= 0; i--)
+                free_page((unsigned long)data->data_pages[i]);
+
+        free_page((unsigned long)data->user_page);
+
+fail_user_page:
+        kfree(data);
+
+fail:
+        return NULL;
+}
+
+static void perf_mmap_free_page(unsigned long addr)
+{
+        struct page *page = virt_to_page((void *)addr);
+
+        page->mapping = NULL;
+        __free_page(page);
+}
+
+static void perf_mmap_data_free(struct perf_mmap_data *data)
+{
+        int i;
+
+        perf_mmap_free_page((unsigned long)data->user_page);
+        for (i = 0; i < data->nr_pages; i++)
+                perf_mmap_free_page((unsigned long)data->data_pages[i]);
+}
+
+#else
+
+/*
+ * Back perf_mmap() with vmalloc memory.
+ *
+ * Required for architectures that have d-cache aliasing issues.
+ */
+
+static struct page *
+perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff)
+{
+        if (pgoff > (1UL << data->data_order))
+                return NULL;
+
+        return vmalloc_to_page((void *)data->user_page + pgoff * PAGE_SIZE);
+}
+
+static void perf_mmap_unmark_page(void *addr)
+{
+        struct page *page = vmalloc_to_page(addr);
+
+        page->mapping = NULL;
+}
+
+static void perf_mmap_data_free_work(struct work_struct *work)
+{
+        struct perf_mmap_data *data;
+        void *base;
+        int i, nr;
+
+        data = container_of(work, struct perf_mmap_data, work);
+        nr = 1 << data->data_order;
+
+        base = data->user_page;
+        for (i = 0; i < nr + 1; i++)
+                perf_mmap_unmark_page(base + (i * PAGE_SIZE));
+
+        vfree(base);
+}
+
+static void perf_mmap_data_free(struct perf_mmap_data *data)
+{
+        schedule_work(&data->work);
+}
+
+static struct perf_mmap_data *
+perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
+{
+        struct perf_mmap_data *data;
+        unsigned long size;
+        void *all_buf;
+
+        WARN_ON(atomic_read(&event->mmap_count));
+
+        size = sizeof(struct perf_mmap_data);
+        size += sizeof(void *);
+
+        data = kzalloc(size, GFP_KERNEL);
+        if (!data)
+                goto fail;
+
+        INIT_WORK(&data->work, perf_mmap_data_free_work);
+
+        all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
+        if (!all_buf)
+                goto fail_all_buf;
+
+        data->user_page = all_buf;
+        data->data_pages[0] = all_buf + PAGE_SIZE;
+        data->data_order = ilog2(nr_pages);
+        data->nr_pages = 1;
+
+        return data;
+
+fail_all_buf:
+        kfree(data);
+
+fail:
+        return NULL;
+}
+
+#endif
+
+static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        struct perf_event *event = vma->vm_file->private_data;
+        struct perf_mmap_data *data;
+        int ret = VM_FAULT_SIGBUS;
+
+        if (vmf->flags & FAULT_FLAG_MKWRITE) {
+                if (vmf->pgoff == 0)
+                        ret = 0;
+                return ret;
+        }
+
+        rcu_read_lock();
+        data = rcu_dereference(event->data);
+        if (!data)
+                goto unlock;
+
+        if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
+                goto unlock;
+
+        vmf->page = perf_mmap_to_page(data, vmf->pgoff);
+        if (!vmf->page)
+                goto unlock;
+
+        get_page(vmf->page);
+        vmf->page->mapping = vma->vm_file->f_mapping;
+        vmf->page->index   = vmf->pgoff;
+
+        ret = 0;
+unlock:
+        rcu_read_unlock();
+
+        return ret;
+}
+
+static void
+perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data)
+{
+        long max_size = perf_data_size(data);
+
+        atomic_set(&data->lock, -1);
+
+        if (event->attr.watermark) {
+                data->watermark = min_t(long, max_size,
+                                        event->attr.wakeup_watermark);
+        }
+
+        if (!data->watermark)
+                data->watermark = max_t(long, PAGE_SIZE, max_size / 2);
+
+
+        rcu_assign_pointer(event->data, data);
+}
+
+static void perf_mmap_data_free_rcu(struct rcu_head *rcu_head)
+{
+        struct perf_mmap_data *data;
+
+        data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
+        perf_mmap_data_free(data);
+        kfree(data);
+}
+
+static void perf_mmap_data_release(struct perf_event *event)
+{
+        struct perf_mmap_data *data = event->data;
+
+        WARN_ON(atomic_read(&event->mmap_count));
+
+        rcu_assign_pointer(event->data, NULL);
+        call_rcu(&data->rcu_head, perf_mmap_data_free_rcu);
+}
+
+static void perf_mmap_open(struct vm_area_struct *vma)
+{
+        struct perf_event *event = vma->vm_file->private_data;
+
+        atomic_inc(&event->mmap_count);
+}
+
+static void perf_mmap_close(struct vm_area_struct *vma)
+{
+        struct perf_event *event = vma->vm_file->private_data;
+
+        WARN_ON_ONCE(event->ctx->parent_ctx);
+        if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) {
+                unsigned long size = perf_data_size(event->data);
+                struct user_struct *user = current_user();
+
+                atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm);
+                vma->vm_mm->locked_vm -= event->data->nr_locked;
+                perf_mmap_data_release(event);
+                mutex_unlock(&event->mmap_mutex);
+        }
+}
+
+static const struct vm_operations_struct perf_mmap_vmops = {
+        .open           = perf_mmap_open,
+        .close          = perf_mmap_close,
+        .fault          = perf_mmap_fault,
+        .page_mkwrite   = perf_mmap_fault,
+};
+
+static int perf_mmap(struct file *file, struct vm_area_struct *vma)
+{
+        struct perf_event *event = file->private_data;
+        unsigned long user_locked, user_lock_limit;
+        struct user_struct *user = current_user();
+        unsigned long locked, lock_limit;
+        struct perf_mmap_data *data;
+        unsigned long vma_size;
+        unsigned long nr_pages;
+        long user_extra, extra;
+        int ret = 0;
+
+        if (!(vma->vm_flags & VM_SHARED))
+                return -EINVAL;
+
+        vma_size = vma->vm_end - vma->vm_start;
+        nr_pages = (vma_size / PAGE_SIZE) - 1;
+
+        /*
+         * If we have data pages ensure they're a power-of-two number, so we
+         * can do bitmasks instead of modulo.
+         */
+        if (nr_pages != 0 && !is_power_of_2(nr_pages))
+                return -EINVAL;
+
+        if (vma_size != PAGE_SIZE * (1 + nr_pages))
+                return -EINVAL;
+
+        if (vma->vm_pgoff != 0)
+                return -EINVAL;
+
+        WARN_ON_ONCE(event->ctx->parent_ctx);
+        mutex_lock(&event->mmap_mutex);
+        if (event->output) {
+                ret = -EINVAL;
+                goto unlock;
+        }
+
+        if (atomic_inc_not_zero(&event->mmap_count)) {
+                if (nr_pages != event->data->nr_pages)
+                        ret = -EINVAL;
+                goto unlock;
+        }
+
+        user_extra = nr_pages + 1;
+        user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
+
+        /*
+         * Increase the limit linearly with more CPUs:
+         */
+        user_lock_limit *= num_online_cpus();
+
+        user_locked = atomic_long_read(&user->locked_vm) + user_extra;
+
+        extra = 0;
+        if (user_locked > user_lock_limit)
+                extra = user_locked - user_lock_limit;
+
+        lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+        lock_limit >>= PAGE_SHIFT;
+        locked = vma->vm_mm->locked_vm + extra;
+
+        if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
+                !capable(CAP_IPC_LOCK)) {
+                ret = -EPERM;
+                goto unlock;
+        }
+
+        WARN_ON(event->data);
+
+        data = perf_mmap_data_alloc(event, nr_pages);
+        ret = -ENOMEM;
+        if (!data)
+                goto unlock;
+
+        ret = 0;
+        perf_mmap_data_init(event, data);
+
+        atomic_set(&event->mmap_count, 1);
+        atomic_long_add(user_extra, &user->locked_vm);
+        vma->vm_mm->locked_vm += extra;
+        event->data->nr_locked = extra;
+        if (vma->vm_flags & VM_WRITE)
+                event->data->writable = 1;
+
+unlock:
+        mutex_unlock(&event->mmap_mutex);
+
+        vma->vm_flags |= VM_RESERVED;
+        vma->vm_ops = &perf_mmap_vmops;
+
+        return ret;
+}
+
+static int perf_fasync(int fd, struct file *filp, int on)
+{
+        struct inode *inode = filp->f_path.dentry->d_inode;
+        struct perf_event *event = filp->private_data;
+        int retval;
+
+        mutex_lock(&inode->i_mutex);
+        retval = fasync_helper(fd, filp, on, &event->fasync);
+        mutex_unlock(&inode->i_mutex);
+
+        if (retval < 0)
+                return retval;
+
+        return 0;
+}
+
+static const struct file_operations perf_fops = {
+        .release                = perf_release,
+        .read                   = perf_read,
+        .poll                   = perf_poll,
+        .unlocked_ioctl         = perf_ioctl,
+        .compat_ioctl           = perf_ioctl,
+        .mmap                   = perf_mmap,
+        .fasync                 = perf_fasync,
+};
+
+/*
+ * Perf event wakeup
+ *
+ * If there's data, ensure we set the poll() state and publish everything
+ * to user-space before waking everybody up.
+ */
+
+void perf_event_wakeup(struct perf_event *event)
+{
+        wake_up_all(&event->waitq);
+
+        if (event->pending_kill) {
+                kill_fasync(&event->fasync, SIGIO, event->pending_kill);
+                event->pending_kill = 0;
+        }
+}
+
+/*
+ * Pending wakeups
+ *
+ * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
+ *
+ * The NMI bit means we cannot possibly take locks. Therefore, maintain a
+ * single linked list and use cmpxchg() to add entries lockless.
+ */
+
+static void perf_pending_event(struct perf_pending_entry *entry)
+{
+        struct perf_event *event = container_of(entry,
+                        struct perf_event, pending);
+
+        if (event->pending_disable) {
+                event->pending_disable = 0;
+                __perf_event_disable(event);
+        }
+
+        if (event->pending_wakeup) {
+                event->pending_wakeup = 0;
+                perf_event_wakeup(event);
+        }
+}
+
+#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
+
+static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
+        PENDING_TAIL,
+};
+
+static void perf_pending_queue(struct perf_pending_entry *entry,
+                               void (*func)(struct perf_pending_entry *))
+{
+        struct perf_pending_entry **head;
+
+        if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
+                return;
+
+        entry->func = func;
+
+        head = &get_cpu_var(perf_pending_head);
+
+        do {
+                entry->next = *head;
+        } while (cmpxchg(head, entry->next, entry) != entry->next);
+
+        set_perf_event_pending();
+
+        put_cpu_var(perf_pending_head);
+}
+
+static int __perf_pending_run(void)
+{
+        struct perf_pending_entry *list;
+        int nr = 0;
+
+        list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
+        while (list != PENDING_TAIL) {
+                void (*func)(struct perf_pending_entry *);
+                struct perf_pending_entry *entry = list;
+
+                list = list->next;
+
+                func = entry->func;
+                entry->next = NULL;
+                /*
+                 * Ensure we observe the unqueue before we issue the wakeup,
+                 * so that we won't be waiting forever.
+                 * -- see perf_not_pending().
+                 */
+                smp_wmb();
+
+                func(entry);
+                nr++;
+        }
+
+        return nr;
+}
+
+static inline int perf_not_pending(struct perf_event *event)
+{
+        /*
+         * If we flush on whatever cpu we run, there is a chance we don't
+         * need to wait.
+         */
+        get_cpu();
+        __perf_pending_run();
+        put_cpu();
+
+        /*
+         * Ensure we see the proper queue state before going to sleep
+         * so that we do not miss the wakeup. -- see perf_pending_handle()
+         */
+        smp_rmb();
+        return event->pending.next == NULL;
+}
+
+static void perf_pending_sync(struct perf_event *event)
+{
+        wait_event(event->waitq, perf_not_pending(event));
+}
+
+void perf_event_do_pending(void)
+{
+        __perf_pending_run();
+}
+
+/*
+ * Callchain support -- arch specific
+ */
+
+__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+{
+        return NULL;
+}
+
+/*
+ * Output
+ */
+static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail,
+                              unsigned long offset, unsigned long head)
+{
+        unsigned long mask;
+
+        if (!data->writable)
+                return true;
+
+        mask = perf_data_size(data) - 1;
+
+        offset = (offset - tail) & mask;
+        head   = (head   - tail) & mask;
+
+        if ((int)(head - offset) < 0)
+                return false;
+
+        return true;
+}
+
+static void perf_output_wakeup(struct perf_output_handle *handle)
+{
+        atomic_set(&handle->data->poll, POLL_IN);
+
+        if (handle->nmi) {
+                handle->event->pending_wakeup = 1;
+                perf_pending_queue(&handle->event->pending,
+                                   perf_pending_event);
+        } else
+                perf_event_wakeup(handle->event);
+}
+
+/*
+ * Curious locking construct.
+ *
+ * We need to ensure a later event_id doesn't publish a head when a former
+ * event_id isn't done writing. However since we need to deal with NMIs we
+ * cannot fully serialize things.
+ *
+ * What we do is serialize between CPUs so we only have to deal with NMI
+ * nesting on a single CPU.
+ *
+ * We only publish the head (and generate a wakeup) when the outer-most
+ * event_id completes.
+ */
+static void perf_output_lock(struct perf_output_handle *handle)
+{
+        struct perf_mmap_data *data = handle->data;
+        int cpu;
+
+        handle->locked = 0;
+
+        local_irq_save(handle->flags);
+        cpu = smp_processor_id();
+
+        if (in_nmi() && atomic_read(&data->lock) == cpu)
+                return;
+
+        while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
+                cpu_relax();
+
+        handle->locked = 1;
+}
+
+static void perf_output_unlock(struct perf_output_handle *handle)
+{
+        struct perf_mmap_data *data = handle->data;
+        unsigned long head;
+        int cpu;
+
+        data->done_head = data->head;
+
+        if (!handle->locked)
+                goto out;
+
+again:
+        /*
+         * The xchg implies a full barrier that ensures all writes are done
+         * before we publish the new head, matched by a rmb() in userspace when
+         * reading this position.
+         */
+        while ((head = atomic_long_xchg(&data->done_head, 0)))
+                data->user_page->data_head = head;
+
+        /*
+         * NMI can happen here, which means we can miss a done_head update.
+         */
+
+        cpu = atomic_xchg(&data->lock, -1);
+        WARN_ON_ONCE(cpu != smp_processor_id());
+
+        /*
+         * Therefore we have to validate we did not indeed do so.
+         */
+        if (unlikely(atomic_long_read(&data->done_head))) {
+                /*
+                 * Since we had it locked, we can lock it again.
+                 */
+                while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
+                        cpu_relax();
+
+                goto again;
+        }
+
+        if (atomic_xchg(&data->wakeup, 0))
+                perf_output_wakeup(handle);
+out:
+        local_irq_restore(handle->flags);
+}
+
+void perf_output_copy(struct perf_output_handle *handle,
+                      const void *buf, unsigned int len)
+{
+        unsigned int pages_mask;
+        unsigned long offset;
+        unsigned int size;
+        void **pages;
+
+        offset          = handle->offset;
+        pages_mask      = handle->data->nr_pages - 1;
+        pages           = handle->data->data_pages;
+
+        do {
+                unsigned long page_offset;
+                unsigned long page_size;
+                int nr;
+
+                nr          = (offset >> PAGE_SHIFT) & pages_mask;
+                page_size   = 1UL << (handle->data->data_order + PAGE_SHIFT);
+                page_offset = offset & (page_size - 1);
+                size        = min_t(unsigned int, page_size - page_offset, len);
+
+                memcpy(pages[nr] + page_offset, buf, size);
+
+                len         -= size;
+                buf         += size;
+                offset      += size;
+        } while (len);
+
+        handle->offset = offset;
+
+        /*
+         * Check we didn't copy past our reservation window, taking the
+         * possible unsigned int wrap into account.
+         */
+        WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
+}
+
+int perf_output_begin(struct perf_output_handle *handle,
+                      struct perf_event *event, unsigned int size,
+                      int nmi, int sample)
+{
+        struct perf_event *output_event;
+        struct perf_mmap_data *data;
+        unsigned long tail, offset, head;
+        int have_lost;
+        struct {
+                struct perf_event_header header;
+                u64                      id;
+                u64                      lost;
+        } lost_event;
+
+        rcu_read_lock();
+        /*
+         * For inherited events we send all the output towards the parent.
+         */
+        if (event->parent)
+                event = event->parent;
+
+        output_event = rcu_dereference(event->output);
+        if (output_event)
+                event = output_event;
+
+        data = rcu_dereference(event->data);
+        if (!data)
+                goto out;
+
+        handle->data    = data;
+        handle->event   = event;
+        handle->nmi     = nmi;
+        handle->sample  = sample;
+
+        if (!data->nr_pages)
+                goto fail;
+
+        have_lost = atomic_read(&data->lost);
+        if (have_lost)
+                size += sizeof(lost_event);
+
+        perf_output_lock(handle);
+
+        do {
+                /*
+                 * Userspace could choose to issue a mb() before updating the
+                 * tail pointer. So that all reads will be completed before the
+                 * write is issued.
+                 */
+                tail = ACCESS_ONCE(data->user_page->data_tail);
+                smp_rmb();
+                offset = head = atomic_long_read(&data->head);
+                head += size;
+                if (unlikely(!perf_output_space(data, tail, offset, head)))
+                        goto fail;
+        } while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
+
+        handle->offset  = offset;
+        handle->head    = head;
+
+        if (head - tail > data->watermark)
+                atomic_set(&data->wakeup, 1);
+
+        if (have_lost) {
+                lost_event.header.type = PERF_RECORD_LOST;
+                lost_event.header.misc = 0;
+                lost_event.header.size = sizeof(lost_event);
+                lost_event.id          = event->id;
+                lost_event.lost        = atomic_xchg(&data->lost, 0);
+
+                perf_output_put(handle, lost_event);
+        }
+
+        return 0;
+
+fail:
+        atomic_inc(&data->lost);
+        perf_output_unlock(handle);
+out:
+        rcu_read_unlock();
+
+        return -ENOSPC;
+}
+
+void perf_output_end(struct perf_output_handle *handle)
+{
+        struct perf_event *event = handle->event;
+        struct perf_mmap_data *data = handle->data;
+
+        int wakeup_events = event->attr.wakeup_events;
+
+        if (handle->sample && wakeup_events) {
+                int events = atomic_inc_return(&data->events);
+                if (events >= wakeup_events) {
+                        atomic_sub(wakeup_events, &data->events);
+                        atomic_set(&data->wakeup, 1);
+                }
+        }
+
+        perf_output_unlock(handle);
+        rcu_read_unlock();
+}
+
+static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
+{
+        /*
+         * only top level events have the pid namespace they were created in
+         */
+        if (event->parent)
+                event = event->parent;
+
+        return task_tgid_nr_ns(p, event->ns);
+}
+
+static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
+{
+        /*
+         * only top level events have the pid namespace they were created in
+         */
+        if (event->parent)
+                event = event->parent;
+
+        return task_pid_nr_ns(p, event->ns);
+}
+
+static void perf_output_read_one(struct perf_output_handle *handle,
+                                 struct perf_event *event)
+{
+        u64 read_format = event->attr.read_format;
+        u64 values[4];
+        int n = 0;
+
+        values[n++] = atomic64_read(&event->count);
+        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+                values[n++] = event->total_time_enabled +
+                        atomic64_read(&event->child_total_time_enabled);
+        }
+        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+                values[n++] = event->total_time_running +
+                        atomic64_read(&event->child_total_time_running);
+        }
+        if (read_format & PERF_FORMAT_ID)
+                values[n++] = primary_event_id(event);
+
+        perf_output_copy(handle, values, n * sizeof(u64));
+}
+
+/*
+ * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
+ */
+static void perf_output_read_group(struct perf_output_handle *handle,
+                            struct perf_event *event)
+{
+        struct perf_event *leader = event->group_leader, *sub;
+        u64 read_format = event->attr.read_format;
+        u64 values[5];
+        int n = 0;
+
+        values[n++] = 1 + leader->nr_siblings;
+
+        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+                values[n++] = leader->total_time_enabled;
+
+        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+                values[n++] = leader->total_time_running;
+
+        if (leader != event)
+                leader->pmu->read(leader);
+
+        values[n++] = atomic64_read(&leader->count);
+        if (read_format & PERF_FORMAT_ID)
+                values[n++] = primary_event_id(leader);
+
+        perf_output_copy(handle, values, n * sizeof(u64));
+
+        list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+                n = 0;
+
+                if (sub != event)
+                        sub->pmu->read(sub);
+
+                values[n++] = atomic64_read(&sub->count);
+                if (read_format & PERF_FORMAT_ID)
+                        values[n++] = primary_event_id(sub);
+
+                perf_output_copy(handle, values, n * sizeof(u64));
+        }
+}
+
+static void perf_output_read(struct perf_output_handle *handle,
+                             struct perf_event *event)
+{
+        if (event->attr.read_format & PERF_FORMAT_GROUP)
+                perf_output_read_group(handle, event);
+        else
+                perf_output_read_one(handle, event);
+}
+
+void perf_output_sample(struct perf_output_handle *handle,
+                        struct perf_event_header *header,
+                        struct perf_sample_data *data,
+                        struct perf_event *event)
+{
+        u64 sample_type = data->type;
+
+        perf_output_put(handle, *header);
+
+        if (sample_type & PERF_SAMPLE_IP)
+                perf_output_put(handle, data->ip);
+
+        if (sample_type & PERF_SAMPLE_TID)
+                perf_output_put(handle, data->tid_entry);
+
+        if (sample_type & PERF_SAMPLE_TIME)
+                perf_output_put(handle, data->time);
+
+        if (sample_type & PERF_SAMPLE_ADDR)
+                perf_output_put(handle, data->addr);
+
+        if (sample_type & PERF_SAMPLE_ID)
+                perf_output_put(handle, data->id);
+
+        if (sample_type & PERF_SAMPLE_STREAM_ID)
+                perf_output_put(handle, data->stream_id);
+
+        if (sample_type & PERF_SAMPLE_CPU)
+                perf_output_put(handle, data->cpu_entry);
+
+        if (sample_type & PERF_SAMPLE_PERIOD)
+                perf_output_put(handle, data->period);
+
+        if (sample_type & PERF_SAMPLE_READ)
+                perf_output_read(handle, event);
+
+        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+                if (data->callchain) {
+                        int size = 1;
+
+                        if (data->callchain)
+                                size += data->callchain->nr;
+
+                        size *= sizeof(u64);
+
+                        perf_output_copy(handle, data->callchain, size);
+                } else {
+                        u64 nr = 0;
+                        perf_output_put(handle, nr);
+                }
+        }
+
+        if (sample_type & PERF_SAMPLE_RAW) {
+                if (data->raw) {
+                        perf_output_put(handle, data->raw->size);
+                        perf_output_copy(handle, data->raw->data,
+                                         data->raw->size);
+                } else {
+                        struct {
+                                u32     size;
+                                u32     data;
+                        } raw = {
+                                .size = sizeof(u32),
+                                .data = 0,
+                        };
+                        perf_output_put(handle, raw);
+                }
+        }
+}
+
+void perf_prepare_sample(struct perf_event_header *header,
+                         struct perf_sample_data *data,
+                         struct perf_event *event,
+                         struct pt_regs *regs)
+{
+        u64 sample_type = event->attr.sample_type;
+
+        data->type = sample_type;
+
+        header->type = PERF_RECORD_SAMPLE;
+        header->size = sizeof(*header);
+
+        header->misc = 0;
+        header->misc |= perf_misc_flags(regs);
+
+        if (sample_type & PERF_SAMPLE_IP) {
+                data->ip = perf_instruction_pointer(regs);
+
+                header->size += sizeof(data->ip);
+        }
+
+        if (sample_type & PERF_SAMPLE_TID) {
+                /* namespace issues */
+                data->tid_entry.pid = perf_event_pid(event, current);
+                data->tid_entry.tid = perf_event_tid(event, current);
+
+                header->size += sizeof(data->tid_entry);
+        }
+
+        if (sample_type & PERF_SAMPLE_TIME) {
+                data->time = perf_clock();
+
+                header->size += sizeof(data->time);
+        }
+
+        if (sample_type & PERF_SAMPLE_ADDR)
+                header->size += sizeof(data->addr);
+
+        if (sample_type & PERF_SAMPLE_ID) {
+                data->id = primary_event_id(event);
+
+                header->size += sizeof(data->id);
+        }
+
+        if (sample_type & PERF_SAMPLE_STREAM_ID) {
+                data->stream_id = event->id;
+
+                header->size += sizeof(data->stream_id);
+        }
+
+        if (sample_type & PERF_SAMPLE_CPU) {
+                data->cpu_entry.cpu             = raw_smp_processor_id();
+                data->cpu_entry.reserved        = 0;
+
+                header->size += sizeof(data->cpu_entry);
+        }
+
+        if (sample_type & PERF_SAMPLE_PERIOD)
+                header->size += sizeof(data->period);
+
+        if (sample_type & PERF_SAMPLE_READ)
+                header->size += perf_event_read_size(event);
+
+        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+                int size = 1;
+
+                data->callchain = perf_callchain(regs);
+
+                if (data->callchain)
+                        size += data->callchain->nr;
+
+                header->size += size * sizeof(u64);
+        }
+
+        if (sample_type & PERF_SAMPLE_RAW) {
+                int size = sizeof(u32);
+
+                if (data->raw)
+                        size += data->raw->size;
+                else
+                        size += sizeof(u32);
+
+                WARN_ON_ONCE(size & (sizeof(u64)-1));
+                header->size += size;
+        }
+}
+
+static void perf_event_output(struct perf_event *event, int nmi,
+                                struct perf_sample_data *data,
+                                struct pt_regs *regs)
+{
+        struct perf_output_handle handle;
+        struct perf_event_header header;
+
+        perf_prepare_sample(&header, data, event, regs);
+
+        if (perf_output_begin(&handle, event, header.size, nmi, 1))
+                return;
+
+        perf_output_sample(&handle, &header, data, event);
+
+        perf_output_end(&handle);
+}
+
+/*
+ * read event_id
+ */
+
+struct perf_read_event {
+        struct perf_event_header        header;
+
+        u32                             pid;
+        u32                             tid;
+};
+
+static void
+perf_event_read_event(struct perf_event *event,
+                        struct task_struct *task)
+{
+        struct perf_output_handle handle;
+        struct perf_read_event read_event = {
+                .header = {
+                        .type = PERF_RECORD_READ,
+                        .misc = 0,
+                        .size = sizeof(read_event) + perf_event_read_size(event),
+                },
+                .pid = perf_event_pid(event, task),
+                .tid = perf_event_tid(event, task),
+        };
+        int ret;
+
+        ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0);
+        if (ret)
+                return;
+
+        perf_output_put(&handle, read_event);
+        perf_output_read(&handle, event);
+
+        perf_output_end(&handle);
+}
+
+/*
+ * task tracking -- fork/exit
+ *
+ * enabled by: attr.comm | attr.mmap | attr.task
+ */
+
+struct perf_task_event {
+        struct task_struct              *task;
+        struct perf_event_context       *task_ctx;
+
+        struct {
+                struct perf_event_header        header;
+
+                u32                             pid;
+                u32                             ppid;
+                u32                             tid;
+                u32                             ptid;
+                u64                             time;
+        } event_id;
+};
+
+static void perf_event_task_output(struct perf_event *event,
+                                     struct perf_task_event *task_event)
+{
+        struct perf_output_handle handle;
+        int size;
+        struct task_struct *task = task_event->task;
+        int ret;
+
+        size  = task_event->event_id.header.size;
+        ret = perf_output_begin(&handle, event, size, 0, 0);
+
+        if (ret)
+                return;
+
+        task_event->event_id.pid = perf_event_pid(event, task);
+        task_event->event_id.ppid = perf_event_pid(event, current);
+
+        task_event->event_id.tid = perf_event_tid(event, task);
+        task_event->event_id.ptid = perf_event_tid(event, current);
+
+        task_event->event_id.time = perf_clock();
+
+        perf_output_put(&handle, task_event->event_id);
+
+        perf_output_end(&handle);
+}
+
+static int perf_event_task_match(struct perf_event *event)
+{
+        if (event->attr.comm || event->attr.mmap || event->attr.task)
+                return 1;
+
+        return 0;
+}
+
+static void perf_event_task_ctx(struct perf_event_context *ctx,
+                                  struct perf_task_event *task_event)
+{
+        struct perf_event *event;
+
+        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+                return;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+                if (perf_event_task_match(event))
+                        perf_event_task_output(event, task_event);
+        }
+        rcu_read_unlock();
+}
+
+static void perf_event_task_event(struct perf_task_event *task_event)
+{
+        struct perf_cpu_context *cpuctx;
+        struct perf_event_context *ctx = task_event->task_ctx;
+
+        cpuctx = &get_cpu_var(perf_cpu_context);
+        perf_event_task_ctx(&cpuctx->ctx, task_event);
+        put_cpu_var(perf_cpu_context);
+
+        rcu_read_lock();
+        if (!ctx)
+                ctx = rcu_dereference(task_event->task->perf_event_ctxp);
+        if (ctx)
+                perf_event_task_ctx(ctx, task_event);
+        rcu_read_unlock();
+}
+
+static void perf_event_task(struct task_struct *task,
+                              struct perf_event_context *task_ctx,
+                              int new)
+{
+        struct perf_task_event task_event;
+
+        if (!atomic_read(&nr_comm_events) &&
+            !atomic_read(&nr_mmap_events) &&
+            !atomic_read(&nr_task_events))
+                return;
+
+        task_event = (struct perf_task_event){
+                .task     = task,
+                .task_ctx = task_ctx,
+                .event_id    = {
+                        .header = {
+                                .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
+                                .misc = 0,
+                                .size = sizeof(task_event.event_id),
+                        },
+                        /* .pid  */
+                        /* .ppid */
+                        /* .tid  */
+                        /* .ptid */
+                },
+        };
+
+        perf_event_task_event(&task_event);
+}
+
+void perf_event_fork(struct task_struct *task)
+{
+        perf_event_task(task, NULL, 1);
+}
+
+/*
+ * comm tracking
+ */
+
+struct perf_comm_event {
+        struct task_struct      *task;
+        char                    *comm;
+        int                     comm_size;
+
+        struct {
+                struct perf_event_header        header;
+
+                u32                             pid;
+                u32                             tid;
+        } event_id;
+};
+
+static void perf_event_comm_output(struct perf_event *event,
+                                     struct perf_comm_event *comm_event)
+{
+        struct perf_output_handle handle;
+        int size = comm_event->event_id.header.size;
+        int ret = perf_output_begin(&handle, event, size, 0, 0);
+
+        if (ret)
+                return;
+
+        comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
+        comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
+
+        perf_output_put(&handle, comm_event->event_id);
+        perf_output_copy(&handle, comm_event->comm,
+                                   comm_event->comm_size);
+        perf_output_end(&handle);
+}
+
+static int perf_event_comm_match(struct perf_event *event)
+{
+        if (event->attr.comm)
+                return 1;
+
+        return 0;
+}
+
+static void perf_event_comm_ctx(struct perf_event_context *ctx,
+                                  struct perf_comm_event *comm_event)
+{
+        struct perf_event *event;
+
+        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+                return;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+                if (perf_event_comm_match(event))
+                        perf_event_comm_output(event, comm_event);
+        }
+        rcu_read_unlock();
+}
+
+static void perf_event_comm_event(struct perf_comm_event *comm_event)
+{
+        struct perf_cpu_context *cpuctx;
+        struct perf_event_context *ctx;
+        unsigned int size;
+        char comm[TASK_COMM_LEN];
+
+        memset(comm, 0, sizeof(comm));
+        strncpy(comm, comm_event->task->comm, sizeof(comm));
+        size = ALIGN(strlen(comm)+1, sizeof(u64));
+
+        comm_event->comm = comm;
+        comm_event->comm_size = size;
+
+        comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
+
+        cpuctx = &get_cpu_var(perf_cpu_context);
+        perf_event_comm_ctx(&cpuctx->ctx, comm_event);
+        put_cpu_var(perf_cpu_context);
+
+        rcu_read_lock();
+        /*
+         * doesn't really matter which of the child contexts the
+         * events ends up in.
+         */
+        ctx = rcu_dereference(current->perf_event_ctxp);
+        if (ctx)
+                perf_event_comm_ctx(ctx, comm_event);
+        rcu_read_unlock();
+}
+
+void perf_event_comm(struct task_struct *task)
+{
+        struct perf_comm_event comm_event;
+
+        if (task->perf_event_ctxp)
+                perf_event_enable_on_exec(task);
+
+        if (!atomic_read(&nr_comm_events))
+                return;
+
+        comm_event = (struct perf_comm_event){
+                .task   = task,
+                /* .comm      */
+                /* .comm_size */
+                .event_id  = {
+                        .header = {
+                                .type = PERF_RECORD_COMM,
+                                .misc = 0,
+                                /* .size */
+                        },
+                        /* .pid */
+                        /* .tid */
+                },
+        };
+
+        perf_event_comm_event(&comm_event);
+}
+
+/*
+ * mmap tracking
+ */
+
+struct perf_mmap_event {
+        struct vm_area_struct   *vma;
+
+        const char              *file_name;
+        int                     file_size;
+
+        struct {
+                struct perf_event_header        header;
+
+                u32                             pid;
+                u32                             tid;
+                u64                             start;
+                u64                             len;
+                u64                             pgoff;
+        } event_id;
+};
+
+static void perf_event_mmap_output(struct perf_event *event,
+                                     struct perf_mmap_event *mmap_event)
+{
+        struct perf_output_handle handle;
+        int size = mmap_event->event_id.header.size;
+        int ret = perf_output_begin(&handle, event, size, 0, 0);
+
+        if (ret)
+                return;
+
+        mmap_event->event_id.pid = perf_event_pid(event, current);
+        mmap_event->event_id.tid = perf_event_tid(event, current);
+
+        perf_output_put(&handle, mmap_event->event_id);
+        perf_output_copy(&handle, mmap_event->file_name,
+                                   mmap_event->file_size);
+        perf_output_end(&handle);
+}
+
+static int perf_event_mmap_match(struct perf_event *event,
+                                   struct perf_mmap_event *mmap_event)
+{
+        if (event->attr.mmap)
+                return 1;
+
+        return 0;
+}
+
+static void perf_event_mmap_ctx(struct perf_event_context *ctx,
+                                  struct perf_mmap_event *mmap_event)
+{
+        struct perf_event *event;
+
+        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+                return;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+                if (perf_event_mmap_match(event, mmap_event))
+                        perf_event_mmap_output(event, mmap_event);
+        }
+        rcu_read_unlock();
+}
+
+static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
+{
+        struct perf_cpu_context *cpuctx;
+        struct perf_event_context *ctx;
+        struct vm_area_struct *vma = mmap_event->vma;
+        struct file *file = vma->vm_file;
+        unsigned int size;
+        char tmp[16];
+        char *buf = NULL;
+        const char *name;
+
+        memset(tmp, 0, sizeof(tmp));
+
+        if (file) {
+                /*
+                 * d_path works from the end of the buffer backwards, so we
+                 * need to add enough zero bytes after the string to handle
+                 * the 64bit alignment we do later.
+                 */
+                buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
+                if (!buf) {
+                        name = strncpy(tmp, "//enomem", sizeof(tmp));
+                        goto got_name;
+                }
+                name = d_path(&file->f_path, buf, PATH_MAX);
+                if (IS_ERR(name)) {
+                        name = strncpy(tmp, "//toolong", sizeof(tmp));
+                        goto got_name;
+                }
+        } else {
+                if (arch_vma_name(mmap_event->vma)) {
+                        name = strncpy(tmp, arch_vma_name(mmap_event->vma),
+                                       sizeof(tmp));
+                        goto got_name;
+                }
+
+                if (!vma->vm_mm) {
+                        name = strncpy(tmp, "[vdso]", sizeof(tmp));
+                        goto got_name;
+                }
+
+                name = strncpy(tmp, "//anon", sizeof(tmp));
+                goto got_name;
+        }
+
+got_name:
+        size = ALIGN(strlen(name)+1, sizeof(u64));
+
+        mmap_event->file_name = name;
+        mmap_event->file_size = size;
+
+        mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
+
+        cpuctx = &get_cpu_var(perf_cpu_context);
+        perf_event_mmap_ctx(&cpuctx->ctx, mmap_event);
+        put_cpu_var(perf_cpu_context);
+
+        rcu_read_lock();
+        /*
+         * doesn't really matter which of the child contexts the
+         * events ends up in.
+         */
+        ctx = rcu_dereference(current->perf_event_ctxp);
+        if (ctx)
+                perf_event_mmap_ctx(ctx, mmap_event);
+        rcu_read_unlock();
+
+        kfree(buf);
+}
+
+void __perf_event_mmap(struct vm_area_struct *vma)
+{
+        struct perf_mmap_event mmap_event;
+
+        if (!atomic_read(&nr_mmap_events))
+                return;
+
+        mmap_event = (struct perf_mmap_event){
+                .vma    = vma,
+                /* .file_name */
+                /* .file_size */
+                .event_id  = {
+                        .header = {
+                                .type = PERF_RECORD_MMAP,
+                                .misc = 0,
+                                /* .size */
+                        },
+                        /* .pid */
+                        /* .tid */
+                        .start  = vma->vm_start,
+                        .len    = vma->vm_end - vma->vm_start,
+                        .pgoff  = vma->vm_pgoff,
+                },
+        };
+
+        perf_event_mmap_event(&mmap_event);
+}
+
+/*
+ * IRQ throttle logging
+ */
+
+static void perf_log_throttle(struct perf_event *event, int enable)
+{
+        struct perf_output_handle handle;
+        int ret;
+
+        struct {
+                struct perf_event_header        header;
+                u64                             time;
+                u64                             id;
+                u64                             stream_id;
+        } throttle_event = {
+                .header = {
+                        .type = PERF_RECORD_THROTTLE,
+                        .misc = 0,
+                        .size = sizeof(throttle_event),
+                },
+                .time           = perf_clock(),
+                .id             = primary_event_id(event),
+                .stream_id      = event->id,
+        };
+
+        if (enable)
+                throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
+
+        ret = perf_output_begin(&handle, event, sizeof(throttle_event), 1, 0);
+        if (ret)
+                return;
+
+        perf_output_put(&handle, throttle_event);
+        perf_output_end(&handle);
+}
+
+/*
+ * Generic event overflow handling, sampling.
+ */
+
+static int __perf_event_overflow(struct perf_event *event, int nmi,
+                                   int throttle, struct perf_sample_data *data,
+                                   struct pt_regs *regs)
+{
+        int events = atomic_read(&event->event_limit);
+        struct hw_perf_event *hwc = &event->hw;
+        int ret = 0;
+
+        throttle = (throttle && event->pmu->unthrottle != NULL);
+
+        if (!throttle) {
+                hwc->interrupts++;
+        } else {
+                if (hwc->interrupts != MAX_INTERRUPTS) {
+                        hwc->interrupts++;
+                        if (HZ * hwc->interrupts >
+                                        (u64)sysctl_perf_event_sample_rate) {
+                                hwc->interrupts = MAX_INTERRUPTS;
+                                perf_log_throttle(event, 0);
+                                ret = 1;
+                        }
+                } else {
+                        /*
+                         * Keep re-disabling events even though on the previous
+                         * pass we disabled it - just in case we raced with a
+                         * sched-in and the event got enabled again:
+                         */
+                        ret = 1;
+                }
+        }
+
+        if (event->attr.freq) {
+                u64 now = perf_clock();
+                s64 delta = now - hwc->freq_stamp;
+
+                hwc->freq_stamp = now;
+
+                if (delta > 0 && delta < TICK_NSEC)
+                        perf_adjust_period(event, NSEC_PER_SEC / (int)delta);
+        }
+
+        /*
+         * XXX event_limit might not quite work as expected on inherited
+         * events
+         */
+
+        event->pending_kill = POLL_IN;
+        if (events && atomic_dec_and_test(&event->event_limit)) {
+                ret = 1;
+                event->pending_kill = POLL_HUP;
+                if (nmi) {
+                        event->pending_disable = 1;
+                        perf_pending_queue(&event->pending,
+                                           perf_pending_event);
+                } else
+                        perf_event_disable(event);
+        }
+
+        perf_event_output(event, nmi, data, regs);
+        return ret;
+}
+
+int perf_event_overflow(struct perf_event *event, int nmi,
+                          struct perf_sample_data *data,
+                          struct pt_regs *regs)
+{
+        return __perf_event_overflow(event, nmi, 1, data, regs);
+}
+
+/*
+ * Generic software event infrastructure
+ */
+
+/*
+ * We directly increment event->count and keep a second value in
+ * event->hw.period_left to count intervals. This period event
+ * is kept in the range [-sample_period, 0] so that we can use the
+ * sign as trigger.
+ */
+
+static u64 perf_swevent_set_period(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+        u64 period = hwc->last_period;
+        u64 nr, offset;
+        s64 old, val;
+
+        hwc->last_period = hwc->sample_period;
+
+again:
+        old = val = atomic64_read(&hwc->period_left);
+        if (val < 0)
+                return 0;
+
+        nr = div64_u64(period + val, period);
+        offset = nr * period;
+        val -= offset;
+        if (atomic64_cmpxchg(&hwc->period_left, old, val) != old)
+                goto again;
+
+        return nr;
+}
+
+static void perf_swevent_overflow(struct perf_event *event,
+                                    int nmi, struct perf_sample_data *data,
+                                    struct pt_regs *regs)
+{
+        struct hw_perf_event *hwc = &event->hw;
+        int throttle = 0;
+        u64 overflow;
+
+        data->period = event->hw.last_period;
+        overflow = perf_swevent_set_period(event);
+
+        if (hwc->interrupts == MAX_INTERRUPTS)
+                return;
+
+        for (; overflow; overflow--) {
+                if (__perf_event_overflow(event, nmi, throttle,
+                                            data, regs)) {
+                        /*
+                         * We inhibit the overflow from happening when
+                         * hwc->interrupts == MAX_INTERRUPTS.
+                         */
+                        break;
+                }
+                throttle = 1;
+        }
+}
+
+static void perf_swevent_unthrottle(struct perf_event *event)
+{
+        /*
+         * Nothing to do, we already reset hwc->interrupts.
+         */
+}
+
+static void perf_swevent_add(struct perf_event *event, u64 nr,
+                               int nmi, struct perf_sample_data *data,
+                               struct pt_regs *regs)
+{
+        struct hw_perf_event *hwc = &event->hw;
+
+        atomic64_add(nr, &event->count);
+
+        if (!hwc->sample_period)
+                return;
+
+        if (!regs)
+                return;
+
+        if (!atomic64_add_negative(nr, &hwc->period_left))
+                perf_swevent_overflow(event, nmi, data, regs);
+}
+
+static int perf_swevent_is_counting(struct perf_event *event)
+{
+        /*
+         * The event is active, we're good!
+         */
+        if (event->state == PERF_EVENT_STATE_ACTIVE)
+                return 1;
+
+        /*
+         * The event is off/error, not counting.
+         */
+        if (event->state != PERF_EVENT_STATE_INACTIVE)
+                return 0;
+
+        /*
+         * The event is inactive, if the context is active
+         * we're part of a group that didn't make it on the 'pmu',
+         * not counting.
+         */
+        if (event->ctx->is_active)
+                return 0;
+
+        /*
+         * We're inactive and the context is too, this means the
+         * task is scheduled out, we're counting events that happen
+         * to us, like migration events.
+         */
+        return 1;
+}
+
+static int perf_swevent_match(struct perf_event *event,
+                                enum perf_type_id type,
+                                u32 event_id, struct pt_regs *regs)
+{
+        if (!perf_swevent_is_counting(event))
+                return 0;
+
+        if (event->attr.type != type)
+                return 0;
+        if (event->attr.config != event_id)
+                return 0;
+
+        if (regs) {
+                if (event->attr.exclude_user && user_mode(regs))
+                        return 0;
+
+                if (event->attr.exclude_kernel && !user_mode(regs))
+                        return 0;
+        }
+
+        return 1;
+}
+
+static void perf_swevent_ctx_event(struct perf_event_context *ctx,
+                                     enum perf_type_id type,
+                                     u32 event_id, u64 nr, int nmi,
+                                     struct perf_sample_data *data,
+                                     struct pt_regs *regs)
+{
+        struct perf_event *event;
+
+        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+                return;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+                if (perf_swevent_match(event, type, event_id, regs))
+                        perf_swevent_add(event, nr, nmi, data, regs);
+        }
+        rcu_read_unlock();
+}
+
+static int *perf_swevent_recursion_context(struct perf_cpu_context *cpuctx)
+{
+        if (in_nmi())
+                return &cpuctx->recursion[3];
+
+        if (in_irq())
+                return &cpuctx->recursion[2];
+
+        if (in_softirq())
+                return &cpuctx->recursion[1];
+
+        return &cpuctx->recursion[0];
+}
+
+static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
+                                    u64 nr, int nmi,
+                                    struct perf_sample_data *data,
+                                    struct pt_regs *regs)
+{
+        struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
+        int *recursion = perf_swevent_recursion_context(cpuctx);
+        struct perf_event_context *ctx;
+
+        if (*recursion)
+                goto out;
+
+        (*recursion)++;
+        barrier();
+
+        perf_swevent_ctx_event(&cpuctx->ctx, type, event_id,
+                                 nr, nmi, data, regs);
+        rcu_read_lock();
+        /*
+         * doesn't really matter which of the child contexts the
+         * events ends up in.
+         */
+        ctx = rcu_dereference(current->perf_event_ctxp);
+        if (ctx)
+                perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs);
+        rcu_read_unlock();
+
+        barrier();
+        (*recursion)--;
+
+out:
+        put_cpu_var(perf_cpu_context);
+}
+
+void __perf_sw_event(u32 event_id, u64 nr, int nmi,
+                            struct pt_regs *regs, u64 addr)
+{
+        struct perf_sample_data data = {
+                .addr = addr,
+        };
+
+        do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi,
+                                &data, regs);
+}
+
+static void perf_swevent_read(struct perf_event *event)
+{
+}
+
+static int perf_swevent_enable(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+
+        if (hwc->sample_period) {
+                hwc->last_period = hwc->sample_period;
+                perf_swevent_set_period(event);
+        }
+        return 0;
+}
+
+static void perf_swevent_disable(struct perf_event *event)
+{
+}
+
+static const struct pmu perf_ops_generic = {
+        .enable         = perf_swevent_enable,
+        .disable        = perf_swevent_disable,
+        .read           = perf_swevent_read,
+        .unthrottle     = perf_swevent_unthrottle,
+};
+
+/*
+ * hrtimer based swevent callback
+ */
+
+static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
+{
+        enum hrtimer_restart ret = HRTIMER_RESTART;
+        struct perf_sample_data data;
+        struct pt_regs *regs;
+        struct perf_event *event;
+        u64 period;
+
+        event   = container_of(hrtimer, struct perf_event, hw.hrtimer);
+        event->pmu->read(event);
+
+        data.addr = 0;
+        regs = get_irq_regs();
+        /*
+         * In case we exclude kernel IPs or are somehow not in interrupt
+         * context, provide the next best thing, the user IP.
+         */
+        if ((event->attr.exclude_kernel || !regs) &&
+                        !event->attr.exclude_user)
+                regs = task_pt_regs(current);
+
+        if (regs) {
+                if (perf_event_overflow(event, 0, &data, regs))
+                        ret = HRTIMER_NORESTART;
+        }
+
+        period = max_t(u64, 10000, event->hw.sample_period);
+        hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+
+        return ret;
+}
+
+/*
+ * Software event: cpu wall time clock
+ */
+
+static void cpu_clock_perf_event_update(struct perf_event *event)
+{
+        int cpu = raw_smp_processor_id();
+        s64 prev;
+        u64 now;
+
+        now = cpu_clock(cpu);
+        prev = atomic64_read(&event->hw.prev_count);
+        atomic64_set(&event->hw.prev_count, now);
+        atomic64_add(now - prev, &event->count);
+}
+
+static int cpu_clock_perf_event_enable(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+        int cpu = raw_smp_processor_id();
+
+        atomic64_set(&hwc->prev_count, cpu_clock(cpu));
+        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        hwc->hrtimer.function = perf_swevent_hrtimer;
+        if (hwc->sample_period) {
+                u64 period = max_t(u64, 10000, hwc->sample_period);
+                __hrtimer_start_range_ns(&hwc->hrtimer,
+                                ns_to_ktime(period), 0,
+                                HRTIMER_MODE_REL, 0);
+        }
+
+        return 0;
+}
+
+static void cpu_clock_perf_event_disable(struct perf_event *event)
+{
+        if (event->hw.sample_period)
+                hrtimer_cancel(&event->hw.hrtimer);
+        cpu_clock_perf_event_update(event);
+}
+
+static void cpu_clock_perf_event_read(struct perf_event *event)
+{
+        cpu_clock_perf_event_update(event);
+}
+
+static const struct pmu perf_ops_cpu_clock = {
+        .enable         = cpu_clock_perf_event_enable,
+        .disable        = cpu_clock_perf_event_disable,
+        .read           = cpu_clock_perf_event_read,
+};
+
+/*
+ * Software event: task time clock
+ */
+
+static void task_clock_perf_event_update(struct perf_event *event, u64 now)
+{
+        u64 prev;
+        s64 delta;
+
+        prev = atomic64_xchg(&event->hw.prev_count, now);
+        delta = now - prev;
+        atomic64_add(delta, &event->count);
+}
+
+static int task_clock_perf_event_enable(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+        u64 now;
+
+        now = event->ctx->time;
+
+        atomic64_set(&hwc->prev_count, now);
+        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        hwc->hrtimer.function = perf_swevent_hrtimer;
+        if (hwc->sample_period) {
+                u64 period = max_t(u64, 10000, hwc->sample_period);
+                __hrtimer_start_range_ns(&hwc->hrtimer,
+                                ns_to_ktime(period), 0,
+                                HRTIMER_MODE_REL, 0);
+        }
+
+        return 0;
+}
+
+static void task_clock_perf_event_disable(struct perf_event *event)
+{
+        if (event->hw.sample_period)
+                hrtimer_cancel(&event->hw.hrtimer);
+        task_clock_perf_event_update(event, event->ctx->time);
+
+}
+
+static void task_clock_perf_event_read(struct perf_event *event)
+{
+        u64 time;
+
+        if (!in_nmi()) {
+                update_context_time(event->ctx);
+                time = event->ctx->time;
+        } else {
+                u64 now = perf_clock();
+                u64 delta = now - event->ctx->timestamp;
+                time = event->ctx->time + delta;
+        }
+
+        task_clock_perf_event_update(event, time);
+}
+
+static const struct pmu perf_ops_task_clock = {
+        .enable         = task_clock_perf_event_enable,
+        .disable        = task_clock_perf_event_disable,
+        .read           = task_clock_perf_event_read,
+};
+
+#ifdef CONFIG_EVENT_PROFILE
+void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
+                          int entry_size)
+{
+        struct perf_raw_record raw = {
+                .size = entry_size,
+                .data = record,
+        };
+
+        struct perf_sample_data data = {
+                .addr = addr,
+                .raw = &raw,
+        };
+
+        struct pt_regs *regs = get_irq_regs();
+
+        if (!regs)
+                regs = task_pt_regs(current);
+
+        do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1,
+                                &data, regs);
+}
+EXPORT_SYMBOL_GPL(perf_tp_event);
+
+extern int ftrace_profile_enable(int);
+extern void ftrace_profile_disable(int);
+
+static void tp_perf_event_destroy(struct perf_event *event)
+{
+        ftrace_profile_disable(event->attr.config);
+}
+
+static const struct pmu *tp_perf_event_init(struct perf_event *event)
+{
+        /*
+         * Raw tracepoint data is a severe data leak, only allow root to
+         * have these.
+         */
+        if ((event->attr.sample_type & PERF_SAMPLE_RAW) &&
+                        perf_paranoid_tracepoint_raw() &&
+                        !capable(CAP_SYS_ADMIN))
+                return ERR_PTR(-EPERM);
+
+        if (ftrace_profile_enable(event->attr.config))
+                return NULL;
+
+        event->destroy = tp_perf_event_destroy;
+
+        return &perf_ops_generic;
+}
+#else
+static const struct pmu *tp_perf_event_init(struct perf_event *event)
+{
+        return NULL;
+}
+#endif
+
+atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
+
+static void sw_perf_event_destroy(struct perf_event *event)
+{
+        u64 event_id = event->attr.config;
+
+        WARN_ON(event->parent);
+
+        atomic_dec(&perf_swevent_enabled[event_id]);
+}
+
+static const struct pmu *sw_perf_event_init(struct perf_event *event)
+{
+        const struct pmu *pmu = NULL;
+        u64 event_id = event->attr.config;
+
+        /*
+         * Software events (currently) can't in general distinguish
+         * between user, kernel and hypervisor events.
+         * However, context switches and cpu migrations are considered
+         * to be kernel events, and page faults are never hypervisor
+         * events.
+         */
+        switch (event_id) {
+        case PERF_COUNT_SW_CPU_CLOCK:
+                pmu = &perf_ops_cpu_clock;
+
+                break;
+        case PERF_COUNT_SW_TASK_CLOCK:
+                /*
+                 * If the user instantiates this as a per-cpu event,
+                 * use the cpu_clock event instead.
+                 */
+                if (event->ctx->task)
+                        pmu = &perf_ops_task_clock;
+                else
+                        pmu = &perf_ops_cpu_clock;
+
+                break;
+        case PERF_COUNT_SW_PAGE_FAULTS:
+        case PERF_COUNT_SW_PAGE_FAULTS_MIN:
+        case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
+        case PERF_COUNT_SW_CONTEXT_SWITCHES:
+        case PERF_COUNT_SW_CPU_MIGRATIONS:
+                if (!event->parent) {
+                        atomic_inc(&perf_swevent_enabled[event_id]);
+                        event->destroy = sw_perf_event_destroy;
+                }
+                pmu = &perf_ops_generic;
+                break;
+        }
+
+        return pmu;
+}
+
+/*
+ * Allocate and initialize a event structure
+ */
+static struct perf_event *
+perf_event_alloc(struct perf_event_attr *attr,
+                   int cpu,
+                   struct perf_event_context *ctx,
+                   struct perf_event *group_leader,
+                   struct perf_event *parent_event,
+                   gfp_t gfpflags)
+{
+        const struct pmu *pmu;
+        struct perf_event *event;
+        struct hw_perf_event *hwc;
+        long err;
+
+        event = kzalloc(sizeof(*event), gfpflags);
+        if (!event)
+                return ERR_PTR(-ENOMEM);
+
+        /*
+         * Single events are their own group leaders, with an
+         * empty sibling list:
+         */
+        if (!group_leader)
+                group_leader = event;
+
+        mutex_init(&event->child_mutex);
+        INIT_LIST_HEAD(&event->child_list);
+
+        INIT_LIST_HEAD(&event->group_entry);
+        INIT_LIST_HEAD(&event->event_entry);
+        INIT_LIST_HEAD(&event->sibling_list);
+        init_waitqueue_head(&event->waitq);
+
+        mutex_init(&event->mmap_mutex);
+
+        event->cpu              = cpu;
+        event->attr             = *attr;
+        event->group_leader     = group_leader;
+        event->pmu              = NULL;
+        event->ctx              = ctx;
+        event->oncpu            = -1;
+
+        event->parent           = parent_event;
+
+        event->ns               = get_pid_ns(current->nsproxy->pid_ns);
+        event->id               = atomic64_inc_return(&perf_event_id);
+
+        event->state            = PERF_EVENT_STATE_INACTIVE;
+
+        if (attr->disabled)
+                event->state = PERF_EVENT_STATE_OFF;
+
+        pmu = NULL;
+
+        hwc = &event->hw;
+        hwc->sample_period = attr->sample_period;
+        if (attr->freq && attr->sample_freq)
+                hwc->sample_period = 1;
+        hwc->last_period = hwc->sample_period;
+
+        atomic64_set(&hwc->period_left, hwc->sample_period);
+
+        /*
+         * we currently do not support PERF_FORMAT_GROUP on inherited events
+         */
+        if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
+                goto done;
+
+        switch (attr->type) {
+        case PERF_TYPE_RAW:
+        case PERF_TYPE_HARDWARE:
+        case PERF_TYPE_HW_CACHE:
+                pmu = hw_perf_event_init(event);
+                break;
+
+        case PERF_TYPE_SOFTWARE:
+                pmu = sw_perf_event_init(event);
+                break;
+
+        case PERF_TYPE_TRACEPOINT:
+                pmu = tp_perf_event_init(event);
+                break;
+
+        default:
+                break;
+        }
+done:
+        err = 0;
+        if (!pmu)
+                err = -EINVAL;
+        else if (IS_ERR(pmu))
+                err = PTR_ERR(pmu);
+
+        if (err) {
+                if (event->ns)
+                        put_pid_ns(event->ns);
+                kfree(event);
+                return ERR_PTR(err);
+        }
+
+        event->pmu = pmu;
+
+        if (!event->parent) {
+                atomic_inc(&nr_events);
+                if (event->attr.mmap)
+                        atomic_inc(&nr_mmap_events);
+                if (event->attr.comm)
+                        atomic_inc(&nr_comm_events);
+                if (event->attr.task)
+                        atomic_inc(&nr_task_events);
+        }
+
+        return event;
+}
+
+static int perf_copy_attr(struct perf_event_attr __user *uattr,
+                          struct perf_event_attr *attr)
+{
+        u32 size;
+        int ret;
+
+        if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
+                return -EFAULT;
+
+        /*
+         * zero the full structure, so that a short copy will be nice.
+         */
+        memset(attr, 0, sizeof(*attr));
+
+        ret = get_user(size, &uattr->size);
+        if (ret)
+                return ret;
+
+        if (size > PAGE_SIZE)   /* silly large */
+                goto err_size;
+
+        if (!size)              /* abi compat */
+                size = PERF_ATTR_SIZE_VER0;
+
+        if (size < PERF_ATTR_SIZE_VER0)
+                goto err_size;
+
+        /*
+         * If we're handed a bigger struct than we know of,
+         * ensure all the unknown bits are 0 - i.e. new
+         * user-space does not rely on any kernel feature
+         * extensions we dont know about yet.
+         */
+        if (size > sizeof(*attr)) {
+                unsigned char __user *addr;
+                unsigned char __user *end;
+                unsigned char val;
+
+                addr = (void __user *)uattr + sizeof(*attr);
+                end  = (void __user *)uattr + size;
+
+                for (; addr < end; addr++) {
+                        ret = get_user(val, addr);
+                        if (ret)
+                                return ret;
+                        if (val)
+                                goto err_size;
+                }
+                size = sizeof(*attr);
+        }
+
+        ret = copy_from_user(attr, uattr, size);
+        if (ret)
+                return -EFAULT;
+
+        /*
+         * If the type exists, the corresponding creation will verify
+         * the attr->config.
+         */
+        if (attr->type >= PERF_TYPE_MAX)
+                return -EINVAL;
+
+        if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
+                return -EINVAL;
+
+        if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
+                return -EINVAL;
+
+        if (attr->read_format & ~(PERF_FORMAT_MAX-1))
+                return -EINVAL;
+
+out:
+        return ret;
+
+err_size:
+        put_user(sizeof(*attr), &uattr->size);
+        ret = -E2BIG;
+        goto out;
+}
+
+int perf_event_set_output(struct perf_event *event, int output_fd)
+{
+        struct perf_event *output_event = NULL;
+        struct file *output_file = NULL;
+        struct perf_event *old_output;
+        int fput_needed = 0;
+        int ret = -EINVAL;
+
+        if (!output_fd)
+                goto set;
+
+        output_file = fget_light(output_fd, &fput_needed);
+        if (!output_file)
+                return -EBADF;
+
+        if (output_file->f_op != &perf_fops)
+                goto out;
+
+        output_event = output_file->private_data;
+
+        /* Don't chain output fds */
+        if (output_event->output)
+                goto out;
+
+        /* Don't set an output fd when we already have an output channel */
+        if (event->data)
+                goto out;
+
+        atomic_long_inc(&output_file->f_count);
+
+set:
+        mutex_lock(&event->mmap_mutex);
+        old_output = event->output;
+        rcu_assign_pointer(event->output, output_event);
+        mutex_unlock(&event->mmap_mutex);
+
+        if (old_output) {
+                /*
+                 * we need to make sure no existing perf_output_*()
+                 * is still referencing this event.
+                 */
+                synchronize_rcu();
+                fput(old_output->filp);
+        }
+
+        ret = 0;
+out:
+        fput_light(output_file, fput_needed);
+        return ret;
+}
+
+/**
+ * sys_perf_event_open - open a performance event, associate it to a task/cpu
+ *
+ * @attr_uptr:  event_id type attributes for monitoring/sampling
+ * @pid:                target pid
+ * @cpu:                target cpu
+ * @group_fd:           group leader event fd
+ */
+SYSCALL_DEFINE5(perf_event_open,
+                struct perf_event_attr __user *, attr_uptr,
+                pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
+{
+        struct perf_event *event, *group_leader;
+        struct perf_event_attr attr;
+        struct perf_event_context *ctx;
+        struct file *event_file = NULL;
+        struct file *group_file = NULL;
+        int fput_needed = 0;
+        int fput_needed2 = 0;
+        int err;
+
+        /* for future expandability... */
+        if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT))
+                return -EINVAL;
+
+        err = perf_copy_attr(attr_uptr, &attr);
+        if (err)
+                return err;
+
+        if (!attr.exclude_kernel) {
+                if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+                        return -EACCES;
+        }
+
+        if (attr.freq) {
+                if (attr.sample_freq > sysctl_perf_event_sample_rate)
+                        return -EINVAL;
+        }
+
+        /*
+         * Get the target context (task or percpu):
+         */
+        ctx = find_get_context(pid, cpu);
+        if (IS_ERR(ctx))
+                return PTR_ERR(ctx);
+
+        /*
+         * Look up the group leader (we will attach this event to it):
+         */
+        group_leader = NULL;
+        if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) {
+                err = -EINVAL;
+                group_file = fget_light(group_fd, &fput_needed);
+                if (!group_file)
+                        goto err_put_context;
+                if (group_file->f_op != &perf_fops)
+                        goto err_put_context;
+
+                group_leader = group_file->private_data;
+                /*
+                 * Do not allow a recursive hierarchy (this new sibling
+                 * becoming part of another group-sibling):
+                 */
+                if (group_leader->group_leader != group_leader)
+                        goto err_put_context;
+                /*
+                 * Do not allow to attach to a group in a different
+                 * task or CPU context:
+                 */
+                if (group_leader->ctx != ctx)
+                        goto err_put_context;
+                /*
+                 * Only a group leader can be exclusive or pinned
+                 */
+                if (attr.exclusive || attr.pinned)
+                        goto err_put_context;
+        }
+
+        event = perf_event_alloc(&attr, cpu, ctx, group_leader,
+                                     NULL, GFP_KERNEL);
+        err = PTR_ERR(event);
+        if (IS_ERR(event))
+                goto err_put_context;
+
+        err = anon_inode_getfd("[perf_event]", &perf_fops, event, 0);
+        if (err < 0)
+                goto err_free_put_context;
+
+        event_file = fget_light(err, &fput_needed2);
+        if (!event_file)
+                goto err_free_put_context;
+
+        if (flags & PERF_FLAG_FD_OUTPUT) {
+                err = perf_event_set_output(event, group_fd);
+                if (err)
+                        goto err_fput_free_put_context;
+        }
+
+        event->filp = event_file;
+        WARN_ON_ONCE(ctx->parent_ctx);
+        mutex_lock(&ctx->mutex);
+        perf_install_in_context(ctx, event, cpu);
+        ++ctx->generation;
+        mutex_unlock(&ctx->mutex);
+
+        event->owner = current;
+        get_task_struct(current);
+        mutex_lock(&current->perf_event_mutex);
+        list_add_tail(&event->owner_entry, &current->perf_event_list);
+        mutex_unlock(&current->perf_event_mutex);
+
+err_fput_free_put_context:
+        fput_light(event_file, fput_needed2);
+
+err_free_put_context:
+        if (err < 0)
+                kfree(event);
+
+err_put_context:
+        if (err < 0)
+                put_ctx(ctx);
+
+        fput_light(group_file, fput_needed);
+
+        return err;
+}
+
+/*
+ * inherit a event from parent task to child task:
+ */
+static struct perf_event *
+inherit_event(struct perf_event *parent_event,
+              struct task_struct *parent,
+              struct perf_event_context *parent_ctx,
+              struct task_struct *child,
+              struct perf_event *group_leader,
+              struct perf_event_context *child_ctx)
+{
+        struct perf_event *child_event;
+
+        /*
+         * Instead of creating recursive hierarchies of events,
+         * we link inherited events back to the original parent,
+         * which has a filp for sure, which we use as the reference
+         * count:
+         */
+        if (parent_event->parent)
+                parent_event = parent_event->parent;
+
+        child_event = perf_event_alloc(&parent_event->attr,
+                                           parent_event->cpu, child_ctx,
+                                           group_leader, parent_event,
+                                           GFP_KERNEL);
+        if (IS_ERR(child_event))
+                return child_event;
+        get_ctx(child_ctx);
+
+        /*
+         * Make the child state follow the state of the parent event,
+         * not its attr.disabled bit.  We hold the parent's mutex,
+         * so we won't race with perf_event_{en, dis}able_family.
+         */
+        if (parent_event->state >= PERF_EVENT_STATE_INACTIVE)
+                child_event->state = PERF_EVENT_STATE_INACTIVE;
+        else
+                child_event->state = PERF_EVENT_STATE_OFF;
+
+        if (parent_event->attr.freq)
+                child_event->hw.sample_period = parent_event->hw.sample_period;
+
+        /*
+         * Link it up in the child's context:
+         */
+        add_event_to_ctx(child_event, child_ctx);
+
+        /*
+         * Get a reference to the parent filp - we will fput it
+         * when the child event exits. This is safe to do because
+         * we are in the parent and we know that the filp still
+         * exists and has a nonzero count:
+         */
+        atomic_long_inc(&parent_event->filp->f_count);
+
+        /*
+         * Link this into the parent event's child list
+         */
+        WARN_ON_ONCE(parent_event->ctx->parent_ctx);
+        mutex_lock(&parent_event->child_mutex);
+        list_add_tail(&child_event->child_list, &parent_event->child_list);
+        mutex_unlock(&parent_event->child_mutex);
+
+        return child_event;
+}
+
+static int inherit_group(struct perf_event *parent_event,
+              struct task_struct *parent,
+              struct perf_event_context *parent_ctx,
+              struct task_struct *child,
+              struct perf_event_context *child_ctx)
+{
+        struct perf_event *leader;
+        struct perf_event *sub;
+        struct perf_event *child_ctr;
+
+        leader = inherit_event(parent_event, parent, parent_ctx,
+                                 child, NULL, child_ctx);
+        if (IS_ERR(leader))
+                return PTR_ERR(leader);
+        list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
+                child_ctr = inherit_event(sub, parent, parent_ctx,
+                                            child, leader, child_ctx);
+                if (IS_ERR(child_ctr))
+                        return PTR_ERR(child_ctr);
+        }
+        return 0;
+}
+
+static void sync_child_event(struct perf_event *child_event,
+                               struct task_struct *child)
+{
+        struct perf_event *parent_event = child_event->parent;
+        u64 child_val;
+
+        if (child_event->attr.inherit_stat)
+                perf_event_read_event(child_event, child);
+
+        child_val = atomic64_read(&child_event->count);
+
+        /*
+         * Add back the child's count to the parent's count:
+         */
+        atomic64_add(child_val, &parent_event->count);
+        atomic64_add(child_event->total_time_enabled,
+                     &parent_event->child_total_time_enabled);
+        atomic64_add(child_event->total_time_running,
+                     &parent_event->child_total_time_running);
+
+        /*
+         * Remove this event from the parent's list
+         */
+        WARN_ON_ONCE(parent_event->ctx->parent_ctx);
+        mutex_lock(&parent_event->child_mutex);
+        list_del_init(&child_event->child_list);
+        mutex_unlock(&parent_event->child_mutex);
+
+        /*
+         * Release the parent event, if this was the last
+         * reference to it.
+         */
+        fput(parent_event->filp);
+}
+
+static void
+__perf_event_exit_task(struct perf_event *child_event,
+                         struct perf_event_context *child_ctx,
+                         struct task_struct *child)
+{
+        struct perf_event *parent_event;
+
+        update_event_times(child_event);
+        perf_event_remove_from_context(child_event);
+
+        parent_event = child_event->parent;
+        /*
+         * It can happen that parent exits first, and has events
+         * that are still around due to the child reference. These
+         * events need to be zapped - but otherwise linger.
+         */
+        if (parent_event) {
+                sync_child_event(child_event, child);
+                free_event(child_event);
+        }
+}
+
+/*
+ * When a child task exits, feed back event values to parent events.
+ */
+void perf_event_exit_task(struct task_struct *child)
+{
+        struct perf_event *child_event, *tmp;
+        struct perf_event_context *child_ctx;
+        unsigned long flags;
+
+        if (likely(!child->perf_event_ctxp)) {
+                perf_event_task(child, NULL, 0);
+                return;
+        }
+
+        local_irq_save(flags);
+        /*
+         * We can't reschedule here because interrupts are disabled,
+         * and either child is current or it is a task that can't be
+         * scheduled, so we are now safe from rescheduling changing
+         * our context.
+         */
+        child_ctx = child->perf_event_ctxp;
+        __perf_event_task_sched_out(child_ctx);
+
+        /*
+         * Take the context lock here so that if find_get_context is
+         * reading child->perf_event_ctxp, we wait until it has
+         * incremented the context's refcount before we do put_ctx below.
+         */
+        spin_lock(&child_ctx->lock);
+        child->perf_event_ctxp = NULL;
+        /*
+         * If this context is a clone; unclone it so it can't get
+         * swapped to another process while we're removing all
+         * the events from it.
+         */
+        unclone_ctx(child_ctx);
+        spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+        /*
+         * Report the task dead after unscheduling the events so that we
+         * won't get any samples after PERF_RECORD_EXIT. We can however still
+         * get a few PERF_RECORD_READ events.
+         */
+        perf_event_task(child, child_ctx, 0);
+
+        /*
+         * We can recurse on the same lock type through:
+         *
+         *   __perf_event_exit_task()
+         *     sync_child_event()
+         *       fput(parent_event->filp)
+         *         perf_release()
+         *           mutex_lock(&ctx->mutex)
+         *
+         * But since its the parent context it won't be the same instance.
+         */
+        mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING);
+
+again:
+        list_for_each_entry_safe(child_event, tmp, &child_ctx->group_list,
+                                 group_entry)
+                __perf_event_exit_task(child_event, child_ctx, child);
+
+        /*
+         * If the last event was a group event, it will have appended all
+         * its siblings to the list, but we obtained 'tmp' before that which
+         * will still point to the list head terminating the iteration.
+         */
+        if (!list_empty(&child_ctx->group_list))
+                goto again;
+
+        mutex_unlock(&child_ctx->mutex);
+
+        put_ctx(child_ctx);
+}
+
+/*
+ * free an unexposed, unused context as created by inheritance by
+ * init_task below, used by fork() in case of fail.
+ */
+void perf_event_free_task(struct task_struct *task)
+{
+        struct perf_event_context *ctx = task->perf_event_ctxp;
+        struct perf_event *event, *tmp;
+
+        if (!ctx)
+                return;
+
+        mutex_lock(&ctx->mutex);
+again:
+        list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) {
+                struct perf_event *parent = event->parent;
+
+                if (WARN_ON_ONCE(!parent))
+                        continue;
+
+                mutex_lock(&parent->child_mutex);
+                list_del_init(&event->child_list);
+                mutex_unlock(&parent->child_mutex);
+
+                fput(parent->filp);
+
+                list_del_event(event, ctx);
+                free_event(event);
+        }
+
+        if (!list_empty(&ctx->group_list))
+                goto again;
+
+        mutex_unlock(&ctx->mutex);
+
+        put_ctx(ctx);
+}
+
+/*
+ * Initialize the perf_event context in task_struct
+ */
+int perf_event_init_task(struct task_struct *child)
+{
+        struct perf_event_context *child_ctx, *parent_ctx;
+        struct perf_event_context *cloned_ctx;
+        struct perf_event *event;
+        struct task_struct *parent = current;
+        int inherited_all = 1;
+        int ret = 0;
+
+        child->perf_event_ctxp = NULL;
+
+        mutex_init(&child->perf_event_mutex);
+        INIT_LIST_HEAD(&child->perf_event_list);
+
+        if (likely(!parent->perf_event_ctxp))
+                return 0;
+
+        /*
+         * This is executed from the parent task context, so inherit
+         * events that have been marked for cloning.
+         * First allocate and initialize a context for the child.
+         */
+
+        child_ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL);
+        if (!child_ctx)
+                return -ENOMEM;
+
+        __perf_event_init_context(child_ctx, child);
+        child->perf_event_ctxp = child_ctx;
+        get_task_struct(child);
+
+        /*
+         * If the parent's context is a clone, pin it so it won't get
+         * swapped under us.
+         */
+        parent_ctx = perf_pin_task_context(parent);
+
+        /*
+         * No need to check if parent_ctx != NULL here; since we saw
+         * it non-NULL earlier, the only reason for it to become NULL
+         * is if we exit, and since we're currently in the middle of
+         * a fork we can't be exiting at the same time.
+         */
+
+        /*
+         * Lock the parent list. No need to lock the child - not PID
+         * hashed yet and not running, so nobody can access it.
+         */
+        mutex_lock(&parent_ctx->mutex);
+
+        /*
+         * We dont have to disable NMIs - we are only looking at
+         * the list, not manipulating it:
+         */
+        list_for_each_entry(event, &parent_ctx->group_list, group_entry) {
+
+                if (!event->attr.inherit) {
+                        inherited_all = 0;
+                        continue;
+                }
+
+                ret = inherit_group(event, parent, parent_ctx,
+                                             child, child_ctx);
+                if (ret) {
+                        inherited_all = 0;
+                        break;
+                }
+        }
+
+        if (inherited_all) {
+                /*
+                 * Mark the child context as a clone of the parent
+                 * context, or of whatever the parent is a clone of.
+                 * Note that if the parent is a clone, it could get
+                 * uncloned at any point, but that doesn't matter
+                 * because the list of events and the generation
+                 * count can't have changed since we took the mutex.
+                 */
+                cloned_ctx = rcu_dereference(parent_ctx->parent_ctx);
+                if (cloned_ctx) {
+                        child_ctx->parent_ctx = cloned_ctx;
+                        child_ctx->parent_gen = parent_ctx->parent_gen;
+                } else {
+                        child_ctx->parent_ctx = parent_ctx;
+                        child_ctx->parent_gen = parent_ctx->generation;
+                }
+                get_ctx(child_ctx->parent_ctx);
+        }
+
+        mutex_unlock(&parent_ctx->mutex);
+
+        perf_unpin_context(parent_ctx);
+
+        return ret;
+}
+
+static void __cpuinit perf_event_init_cpu(int cpu)
+{
+        struct perf_cpu_context *cpuctx;
+
+        cpuctx = &per_cpu(perf_cpu_context, cpu);
+        __perf_event_init_context(&cpuctx->ctx, NULL);
+
+        spin_lock(&perf_resource_lock);
+        cpuctx->max_pertask = perf_max_events - perf_reserved_percpu;
+        spin_unlock(&perf_resource_lock);
+
+        hw_perf_event_setup(cpu);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void __perf_event_exit_cpu(void *info)
+{
+        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+        struct perf_event_context *ctx = &cpuctx->ctx;
+        struct perf_event *event, *tmp;
+
+        list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry)
+                __perf_event_remove_from_context(event);
+}
+static void perf_event_exit_cpu(int cpu)
+{
+        struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+        struct perf_event_context *ctx = &cpuctx->ctx;
+
+        mutex_lock(&ctx->mutex);
+        smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1);
+        mutex_unlock(&ctx->mutex);
+}
+#else
+static inline void perf_event_exit_cpu(int cpu) { }
+#endif
+
+static int __cpuinit
+perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
+{
+        unsigned int cpu = (long)hcpu;
+
+        switch (action) {
+
+        case CPU_UP_PREPARE:
+        case CPU_UP_PREPARE_FROZEN:
+                perf_event_init_cpu(cpu);
+                break;
+
+        case CPU_ONLINE:
+        case CPU_ONLINE_FROZEN:
+                hw_perf_event_setup_online(cpu);
+                break;
+
+        case CPU_DOWN_PREPARE:
+        case CPU_DOWN_PREPARE_FROZEN:
+                perf_event_exit_cpu(cpu);
+                break;
+
+        default:
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
+/*
+ * This has to have a higher priority than migration_notifier in sched.c.
+ */
+static struct notifier_block __cpuinitdata perf_cpu_nb = {
+        .notifier_call          = perf_cpu_notify,
+        .priority               = 20,
+};
+
+void __init perf_event_init(void)
+{
+        perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
+                        (void *)(long)smp_processor_id());
+        perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,
+                        (void *)(long)smp_processor_id());
+        register_cpu_notifier(&perf_cpu_nb);
+}
+
+static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf)
+{
+        return sprintf(buf, "%d\n", perf_reserved_percpu);
+}
+
+static ssize_t
+perf_set_reserve_percpu(struct sysdev_class *class,
+                        const char *buf,
+                        size_t count)
+{
+        struct perf_cpu_context *cpuctx;
+        unsigned long val;
+        int err, cpu, mpt;
+
+        err = strict_strtoul(buf, 10, &val);
+        if (err)
+                return err;
+        if (val > perf_max_events)
+                return -EINVAL;
+
+        spin_lock(&perf_resource_lock);
+        perf_reserved_percpu = val;
+        for_each_online_cpu(cpu) {
+                cpuctx = &per_cpu(perf_cpu_context, cpu);
+                spin_lock_irq(&cpuctx->ctx.lock);
+                mpt = min(perf_max_events - cpuctx->ctx.nr_events,
+                          perf_max_events - perf_reserved_percpu);
+                cpuctx->max_pertask = mpt;
+                spin_unlock_irq(&cpuctx->ctx.lock);
+        }
+        spin_unlock(&perf_resource_lock);
+
+        return count;
+}
+
+static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf)
+{
+        return sprintf(buf, "%d\n", perf_overcommit);
+}
+
+static ssize_t
+perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
+{
+        unsigned long val;
+        int err;
+
+        err = strict_strtoul(buf, 10, &val);
+        if (err)
+                return err;
+        if (val > 1)
+                return -EINVAL;
+
+        spin_lock(&perf_resource_lock);
+        perf_overcommit = val;
+        spin_unlock(&perf_resource_lock);
+
+        return count;
+}
+
+static SYSDEV_CLASS_ATTR(
+                                reserve_percpu,
+                                0644,
+                                perf_show_reserve_percpu,
+                                perf_set_reserve_percpu
+                        );
+
+static SYSDEV_CLASS_ATTR(
+                                overcommit,
+                                0644,
+                                perf_show_overcommit,
+                                perf_set_overcommit
+                        );
+
+static struct attribute *perfclass_attrs[] = {
+        &attr_reserve_percpu.attr,
+        &attr_overcommit.attr,
+        NULL
+};
+
+static struct attribute_group perfclass_attr_group = {
+        .attrs                  = perfclass_attrs,
+        .name                   = "perf_events",
+};
+
+static int __init perf_event_sysfs_init(void)
+{
+        return sysfs_create_group(&cpu_sysdev_class.kset.kobj,
+                                  &perfclass_attr_group);
+}
+device_initcall(perf_event_sysfs_init);
diff --git a/kernel/pid.c b/kernel/pid.c
index 31310b5d3f50..d3f722d20f9c 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -40,7 +40,7 @@
 #define pid_hashfn(nr, ns)      \
         hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
 static struct hlist_head *pid_hash;
-static int pidhash_shift;
+static unsigned int pidhash_shift = 4;
 struct pid init_struct_pid = INIT_STRUCT_PID;
 
 int pid_max = PID_MAX_DEFAULT;
@@ -499,19 +499,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
 void __init pidhash_init(void)
 {
         int i, pidhash_size;
-        unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT);
 
-        pidhash_shift = max(4, fls(megabytes * 4));
-        pidhash_shift = min(12, pidhash_shift);
+        pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18,
+                                           HASH_EARLY | HASH_SMALL,
+                                           &pidhash_shift, NULL, 4096);
         pidhash_size = 1 << pidhash_shift;
 
-        printk("PID hash table entries: %d (order: %d, %Zd bytes)\n",
-                pidhash_size, pidhash_shift,
-                pidhash_size * sizeof(struct hlist_head));
-
-        pid_hash = alloc_bootmem(pidhash_size * sizeof(*(pid_hash)));
-        if (!pid_hash)
-                panic("Could not alloc pidhash!\n");
         for (i = 0; i < pidhash_size; i++)
                 INIT_HLIST_HEAD(&pid_hash[i]);
 }
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 821722ae58a7..86b3796b0436 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -118,7 +118,7 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old
 {
         if (!(flags & CLONE_NEWPID))
                 return get_pid_ns(old_ns);
-        if (flags & CLONE_THREAD)
+        if (flags & (CLONE_THREAD|CLONE_PARENT))
                 return ERR_PTR(-EINVAL);
         return create_pid_namespace(old_ns);
 }
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index e33a21cb9407..5c9dc228747b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -8,17 +8,18 @@
 #include <linux/math64.h>
 #include <asm/uaccess.h>
 #include <linux/kernel_stat.h>
+#include <trace/events/timer.h>
 
 /*
  * Called after updating RLIMIT_CPU to set timer expiration if necessary.
  */
 void update_rlimit_cpu(unsigned long rlim_new)
 {
-        cputime_t cputime;
+        cputime_t cputime = secs_to_cputime(rlim_new);
+        struct signal_struct *const sig = current->signal;
 
-        cputime = secs_to_cputime(rlim_new);
-        if (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
-            cputime_gt(current->signal->it_prof_expires, cputime)) {
+        if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
+            cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
                 spin_lock_irq(&current->sighand->siglock);
                 set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
                 spin_unlock_irq(&current->sighand->siglock);
@@ -542,6 +543,17 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
                                              now);
 }
 
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+        return cputime_eq(expires, cputime_zero) ||
+               cputime_gt(expires, new_exp);
+}
+
+static inline int expires_le(cputime_t expires, cputime_t new_exp)
+{
+        return !cputime_eq(expires, cputime_zero) &&
+               cputime_le(expires, new_exp);
+}
 /*
  * Insert the timer on the appropriate list before any timers that
  * expire later.  This must be called with the tasklist_lock held
@@ -586,34 +598,32 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
                  */
 
                 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+                        union cpu_time_count *exp = &nt->expires;
+
                         switch (CPUCLOCK_WHICH(timer->it_clock)) {
                         default:
                                 BUG();
                         case CPUCLOCK_PROF:
-                                if (cputime_eq(p->cputime_expires.prof_exp,
-                                               cputime_zero) ||
-                                    cputime_gt(p->cputime_expires.prof_exp,
-                                               nt->expires.cpu))
-                                        p->cputime_expires.prof_exp =
-                                                nt->expires.cpu;
+                                if (expires_gt(p->cputime_expires.prof_exp,
+                                               exp->cpu))
+                                        p->cputime_expires.prof_exp = exp->cpu;
                                 break;
                         case CPUCLOCK_VIRT:
-                                if (cputime_eq(p->cputime_expires.virt_exp,
-                                               cputime_zero) ||
-                                    cputime_gt(p->cputime_expires.virt_exp,
-                                               nt->expires.cpu))
-                                        p->cputime_expires.virt_exp =
-                                                nt->expires.cpu;
+                                if (expires_gt(p->cputime_expires.virt_exp,
+                                               exp->cpu))
+                                        p->cputime_expires.virt_exp = exp->cpu;
                                 break;
                         case CPUCLOCK_SCHED:
                                 if (p->cputime_expires.sched_exp == 0 ||
-                                    p->cputime_expires.sched_exp >
-                                                        nt->expires.sched)
+                                    p->cputime_expires.sched_exp > exp->sched)
                                         p->cputime_expires.sched_exp =
-                                                nt->expires.sched;
+                                                                exp->sched;
                                 break;
                         }
                 } else {
+                        struct signal_struct *const sig = p->signal;
+                        union cpu_time_count *exp = &timer->it.cpu.expires;
+
                         /*
                          * For a process timer, set the cached expiration time.
                          */
@@ -621,30 +631,23 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
                         default:
                                 BUG();
                         case CPUCLOCK_VIRT:
-                                if (!cputime_eq(p->signal->it_virt_expires,
-                                                cputime_zero) &&
-                                    cputime_lt(p->signal->it_virt_expires,
-                                               timer->it.cpu.expires.cpu))
+                                if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
+                                               exp->cpu))
                                         break;
-                                p->signal->cputime_expires.virt_exp =
-                                        timer->it.cpu.expires.cpu;
+                                sig->cputime_expires.virt_exp = exp->cpu;
                                 break;
                         case CPUCLOCK_PROF:
-                                if (!cputime_eq(p->signal->it_prof_expires,
-                                                cputime_zero) &&
-                                    cputime_lt(p->signal->it_prof_expires,
-                                               timer->it.cpu.expires.cpu))
+                                if (expires_le(sig->it[CPUCLOCK_PROF].expires,
+                                               exp->cpu))
                                         break;
-                                i = p->signal->rlim[RLIMIT_CPU].rlim_cur;
+                                i = sig->rlim[RLIMIT_CPU].rlim_cur;
                                 if (i != RLIM_INFINITY &&
-                                    i <= cputime_to_secs(timer->it.cpu.expires.cpu))
+                                    i <= cputime_to_secs(exp->cpu))
                                         break;
-                                p->signal->cputime_expires.prof_exp =
-                                        timer->it.cpu.expires.cpu;
+                                sig->cputime_expires.prof_exp = exp->cpu;
                                 break;
                         case CPUCLOCK_SCHED:
-                                p->signal->cputime_expires.sched_exp =
-                                        timer->it.cpu.expires.sched;
+                                sig->cputime_expires.sched_exp = exp->sched;
                                 break;
                         }
                 }
@@ -1071,6 +1074,40 @@ static void stop_process_timers(struct task_struct *tsk)
         spin_unlock_irqrestore(&cputimer->lock, flags);
 }
 
+static u32 onecputick;
+
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+                             cputime_t *expires, cputime_t cur_time, int signo)
+{
+        if (cputime_eq(it->expires, cputime_zero))
+                return;
+
+        if (cputime_ge(cur_time, it->expires)) {
+                if (!cputime_eq(it->incr, cputime_zero)) {
+                        it->expires = cputime_add(it->expires, it->incr);
+                        it->error += it->incr_error;
+                        if (it->error >= onecputick) {
+                                it->expires = cputime_sub(it->expires,
+                                                          cputime_one_jiffy);
+                                it->error -= onecputick;
+                        }
+                } else {
+                        it->expires = cputime_zero;
+                }
+
+                trace_itimer_expire(signo == SIGPROF ?
+                                    ITIMER_PROF : ITIMER_VIRTUAL,
+                                    tsk->signal->leader_pid, cur_time);
+                __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
+        }
+
+        if (!cputime_eq(it->expires, cputime_zero) &&
+            (cputime_eq(*expires, cputime_zero) ||
+             cputime_lt(it->expires, *expires))) {
+                *expires = it->expires;
+        }
+}
+
 /*
  * Check for any per-thread CPU timers that have fired and move them
  * off the tsk->*_timers list onto the firing list.  Per-thread timers
@@ -1090,10 +1127,10 @@ static void check_process_timers(struct task_struct *tsk,
          * Don't sample the current process CPU clocks if there are no timers.
          */
         if (list_empty(&timers[CPUCLOCK_PROF]) &&
-            cputime_eq(sig->it_prof_expires, cputime_zero) &&
+            cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
             sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
             list_empty(&timers[CPUCLOCK_VIRT]) &&
-            cputime_eq(sig->it_virt_expires, cputime_zero) &&
+            cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
             list_empty(&timers[CPUCLOCK_SCHED])) {
                 stop_process_timers(tsk);
                 return;
@@ -1153,38 +1190,11 @@ static void check_process_timers(struct task_struct *tsk,
         /*
          * Check for the special case process timers.
          */
-        if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-                if (cputime_ge(ptime, sig->it_prof_expires)) {
-                        /* ITIMER_PROF fires and reloads.  */
-                        sig->it_prof_expires = sig->it_prof_incr;
-                        if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-                                sig->it_prof_expires = cputime_add(
-                                        sig->it_prof_expires, ptime);
-                        }
-                        __group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk);
-                }
-                if (!cputime_eq(sig->it_prof_expires, cputime_zero) &&
-                    (cputime_eq(prof_expires, cputime_zero) ||
-                     cputime_lt(sig->it_prof_expires, prof_expires))) {
-                        prof_expires = sig->it_prof_expires;
-                }
-        }
-        if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-                if (cputime_ge(utime, sig->it_virt_expires)) {
-                        /* ITIMER_VIRTUAL fires and reloads.  */
-                        sig->it_virt_expires = sig->it_virt_incr;
-                        if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-                                sig->it_virt_expires = cputime_add(
-                                        sig->it_virt_expires, utime);
-                        }
-                        __group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk);
-                }
-                if (!cputime_eq(sig->it_virt_expires, cputime_zero) &&
-                    (cputime_eq(virt_expires, cputime_zero) ||
-                     cputime_lt(sig->it_virt_expires, virt_expires))) {
-                        virt_expires = sig->it_virt_expires;
-                }
-        }
+        check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
+                         SIGPROF);
+        check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
+                         SIGVTALRM);
+
         if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
                 unsigned long psecs = cputime_to_secs(ptime);
                 cputime_t x;
@@ -1457,7 +1467,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
                 if (!cputime_eq(*oldval, cputime_zero)) {
                         if (cputime_le(*oldval, now.cpu)) {
                                 /* Just about to fire. */
-                                *oldval = jiffies_to_cputime(1);
+                                *oldval = cputime_one_jiffy;
                         } else {
                                 *oldval = cputime_sub(*oldval, now.cpu);
                         }
@@ -1703,10 +1713,15 @@ static __init int init_posix_cpu_timers(void)
                 .nsleep = thread_cpu_nsleep,
                 .nsleep_restart = thread_cpu_nsleep_restart,
         };
+        struct timespec ts;
 
         register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
         register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
 
+        cputime_to_timespec(cputime_one_jiffy, &ts);
+        onecputick = ts.tv_nsec;
+        WARN_ON(ts.tv_sec != 0);
+
         return 0;
 }
 __initcall(init_posix_cpu_timers);
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index d089d052c4a9..495440779ce3 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -242,6 +242,25 @@ static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
         return 0;
 }
 
+
+static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
+{
+        *tp = current_kernel_time();
+        return 0;
+}
+
+static int posix_get_monotonic_coarse(clockid_t which_clock,
+                                                struct timespec *tp)
+{
+        *tp = get_monotonic_coarse();
+        return 0;
+}
+
+int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
+{
+        *tp = ktime_to_timespec(KTIME_LOW_RES);
+        return 0;
+}
 /*
  * Initialize everything, well, just everything in Posix clocks/timers ;)
  */
@@ -262,10 +281,26 @@ static __init int init_posix_timers(void)
                 .timer_create = no_timer_create,
                 .nsleep = no_nsleep,
         };
+        struct k_clock clock_realtime_coarse = {
+                .clock_getres = posix_get_coarse_res,
+                .clock_get = posix_get_realtime_coarse,
+                .clock_set = do_posix_clock_nosettime,
+                .timer_create = no_timer_create,
+                .nsleep = no_nsleep,
+        };
+        struct k_clock clock_monotonic_coarse = {
+                .clock_getres = posix_get_coarse_res,
+                .clock_get = posix_get_monotonic_coarse,
+                .clock_set = do_posix_clock_nosettime,
+                .timer_create = no_timer_create,
+                .nsleep = no_nsleep,
+        };
 
         register_posix_clock(CLOCK_REALTIME, &clock_realtime);
         register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
         register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
+        register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
+        register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
 
         posix_timers_cache = kmem_cache_create("posix_timers_cache",
                                         sizeof (struct k_itimer), 0, SLAB_PANIC,
diff --git a/kernel/power/console.c b/kernel/power/console.c
index a3961b205de7..5187136fe1de 100644
--- a/kernel/power/console.c
+++ b/kernel/power/console.c
@@ -14,56 +14,13 @@
 #define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
 
 static int orig_fgconsole, orig_kmsg;
-static int disable_vt_switch;
-
-/*
- * Normally during a suspend, we allocate a new console and switch to it.
- * When we resume, we switch back to the original console.  This switch
- * can be slow, so on systems where the framebuffer can handle restoration
- * of video registers anyways, there's little point in doing the console
- * switch.  This function allows you to disable it by passing it '0'.
- */
-void pm_set_vt_switch(int do_switch)
-{
-        acquire_console_sem();
-        disable_vt_switch = !do_switch;
-        release_console_sem();
-}
-EXPORT_SYMBOL(pm_set_vt_switch);
 
 int pm_prepare_console(void)
 {
-        acquire_console_sem();
-
-        if (disable_vt_switch) {
-                release_console_sem();
-                return 0;
-        }
-
-        orig_fgconsole = fg_console;
-
-        if (vc_allocate(SUSPEND_CONSOLE)) {
-          /* we can't have a free VC for now. Too bad,
-           * we don't want to mess the screen for now. */
-                release_console_sem();
+        orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
+        if (orig_fgconsole < 0)
                 return 1;
-        }
 
-        if (set_console(SUSPEND_CONSOLE)) {
-                /*
-                 * We're unable to switch to the SUSPEND_CONSOLE.
-                 * Let the calling function know so it can decide
-                 * what to do.
-                 */
-                release_console_sem();
-                return 1;
-        }
-        release_console_sem();
-
-        if (vt_waitactive(SUSPEND_CONSOLE)) {
-                pr_debug("Suspend: Can't switch VCs.");
-                return 1;
-        }
         orig_kmsg = kmsg_redirect;
         kmsg_redirect = SUSPEND_CONSOLE;
         return 0;
@@ -71,19 +28,9 @@ int pm_prepare_console(void)
 
 void pm_restore_console(void)
 {
-        acquire_console_sem();
-        if (disable_vt_switch) {
-                release_console_sem();
-                return;
-        }
-        set_console(orig_fgconsole);
-        release_console_sem();
-
-        if (vt_waitactive(orig_fgconsole)) {
-                pr_debug("Resume: Can't switch VCs.");
-                return;
+        if (orig_fgconsole >= 0) {
+                vt_move_to_console(orig_fgconsole, 0);
+                kmsg_redirect = orig_kmsg;
         }
-
-        kmsg_redirect = orig_kmsg;
 }
 #endif
diff --git a/kernel/power/process.c b/kernel/power/process.c
index da2072d73811..cc2e55373b68 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -9,6 +9,7 @@
 #undef DEBUG
 
 #include <linux/interrupt.h>
+#include <linux/oom.h>
 #include <linux/suspend.h>
 #include <linux/module.h>
 #include <linux/syscalls.h>
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 97955b0e44f4..36cb168e4330 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -619,7 +619,7 @@ __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn,
                 BUG_ON(!region);
         } else
                 /* This allocation cannot fail */
-                region = alloc_bootmem_low(sizeof(struct nosave_region));
+                region = alloc_bootmem(sizeof(struct nosave_region));
         region->start_pfn = start_pfn;
         region->end_pfn = end_pfn;
         list_add_tail(&region->list, &nosave_regions);
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 17d8bb1acf9c..25596e450ac7 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -19,7 +19,7 @@
  * The time it takes is system-specific though, so when we test this
  * during system bootup we allow a LOT of time.
  */
-#define TEST_SUSPEND_SECONDS    5
+#define TEST_SUSPEND_SECONDS    10
 
 static unsigned long suspend_test_start_time;
 
@@ -49,7 +49,8 @@ void suspend_test_finish(const char *label)
          * has some performance issues.  The stack dump of a WARN_ON
          * is more likely to get the right attention than a printk...
          */
-        WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
+        WARN(msec > (TEST_SUSPEND_SECONDS * 1000),
+             "Component: %s, time: %u\n", label, msec);
 }
 
 /*
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 8ba052c86d48..b101cdc4df3f 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -13,7 +13,6 @@
 
 #include <linux/module.h>
 #include <linux/file.h>
-#include <linux/utsname.h>
 #include <linux/delay.h>
 #include <linux/bitops.h>
 #include <linux/genhd.h>
diff --git a/kernel/printk.c b/kernel/printk.c
index 602033acd6c7..f38b07f78a4e 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -206,12 +206,11 @@ __setup("log_buf_len=", log_buf_len_setup);
 #ifdef CONFIG_BOOT_PRINTK_DELAY
 
 static unsigned int boot_delay; /* msecs delay after each printk during bootup */
-static unsigned long long printk_delay_msec; /* per msec, based on boot_delay */
+static unsigned long long loops_per_msec;       /* based on boot_delay */
 
 static int __init boot_delay_setup(char *str)
 {
         unsigned long lpj;
-        unsigned long long loops_per_msec;
 
         lpj = preset_lpj ? preset_lpj : 1000000;        /* some guess */
         loops_per_msec = (unsigned long long)lpj / 1000 * HZ;
@@ -220,10 +219,9 @@ static int __init boot_delay_setup(char *str)
         if (boot_delay > 10 * 1000)
                 boot_delay = 0;
 
-        printk_delay_msec = loops_per_msec;
-        printk(KERN_DEBUG "boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
-                "HZ: %d, printk_delay_msec: %llu\n",
-                boot_delay, preset_lpj, lpj, HZ, printk_delay_msec);
+        pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
+                "HZ: %d, loops_per_msec: %llu\n",
+                boot_delay, preset_lpj, lpj, HZ, loops_per_msec);
         return 1;
 }
 __setup("boot_delay=", boot_delay_setup);
@@ -236,7 +234,7 @@ static void boot_delay_msec(void)
         if (boot_delay == 0 || system_state != SYSTEM_BOOTING)
                 return;
 
-        k = (unsigned long long)printk_delay_msec * boot_delay;
+        k = (unsigned long long)loops_per_msec * boot_delay;
 
         timeout = jiffies + msecs_to_jiffies(boot_delay);
         while (k) {
@@ -655,6 +653,20 @@ static int recursion_bug;
 static int new_text_line = 1;
 static char printk_buf[1024];
 
+int printk_delay_msec __read_mostly;
+
+static inline void printk_delay(void)
+{
+        if (unlikely(printk_delay_msec)) {
+                int m = printk_delay_msec;
+
+                while (m--) {
+                        mdelay(1);
+                        touch_nmi_watchdog();
+                }
+        }
+}
+
 asmlinkage int vprintk(const char *fmt, va_list args)
 {
         int printed_len = 0;
@@ -664,6 +676,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
         char *p;
 
         boot_delay_msec();
+        printk_delay();
 
         preempt_disable();
         /* This stops the holder of console_sem just where we want him */
diff --git a/kernel/profile.c b/kernel/profile.c
index 419250ebec4d..a55d3a367ae8 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -442,48 +442,51 @@ void profile_tick(int type)
 
 #ifdef CONFIG_PROC_FS
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <asm/uaccess.h>
 
-static int prof_cpu_mask_read_proc(char *page, char **start, off_t off,
-                        int count, int *eof, void *data)
+static int prof_cpu_mask_proc_show(struct seq_file *m, void *v)
 {
-        int len = cpumask_scnprintf(page, count, data);
-        if (count - len < 2)
-                return -EINVAL;
-        len += sprintf(page + len, "\n");
-        return len;
+        seq_cpumask(m, prof_cpu_mask);
+        seq_putc(m, '\n');
+        return 0;
 }
 
-static int prof_cpu_mask_write_proc(struct file *file,
-        const char __user *buffer,  unsigned long count, void *data)
+static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, prof_cpu_mask_proc_show, NULL);
+}
+
+static ssize_t prof_cpu_mask_proc_write(struct file *file,
+        const char __user *buffer, size_t count, loff_t *pos)
 {
-        struct cpumask *mask = data;
-        unsigned long full_count = count, err;
         cpumask_var_t new_value;
+        int err;
 
         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
                 return -ENOMEM;
 
         err = cpumask_parse_user(buffer, count, new_value);
         if (!err) {
-                cpumask_copy(mask, new_value);
-                err = full_count;
+                cpumask_copy(prof_cpu_mask, new_value);
+                err = count;
         }
         free_cpumask_var(new_value);
         return err;
 }
 
+static const struct file_operations prof_cpu_mask_proc_fops = {
+        .open           = prof_cpu_mask_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+        .write          = prof_cpu_mask_proc_write,
+};
+
 void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir)
 {
-        struct proc_dir_entry *entry;
-
         /* create /proc/irq/prof_cpu_mask */
-        entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
-        if (!entry)
-                return;
-        entry->data = prof_cpu_mask;
-        entry->read_proc = prof_cpu_mask_read_proc;
-        entry->write_proc = prof_cpu_mask_write_proc;
+        proc_create("prof_cpu_mask", 0600, root_irq_dir, &prof_cpu_mask_proc_fops);
 }
 
 /*
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 307c285af59e..23bd09cd042e 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -266,9 +266,10 @@ static int ignoring_children(struct sighand_struct *sigh)
  * or self-reaping.  Do notification now if it would have happened earlier.
  * If it should reap itself, return true.
  *
- * If it's our own child, there is no notification to do.
- * But if our normal children self-reap, then this child
- * was prevented by ptrace and we must reap it now.
+ * If it's our own child, there is no notification to do. But if our normal
+ * children self-reap, then this child was prevented by ptrace and we must
+ * reap it now, in that case we must also wake up sub-threads sleeping in
+ * do_wait().
  */
 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
 {
@@ -278,8 +279,10 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
                 if (!task_detached(p) && thread_group_empty(p)) {
                         if (!same_thread_group(p->real_parent, tracer))
                                 do_notify_parent(p, p->exit_signal);
-                        else if (ignoring_children(tracer->sighand))
+                        else if (ignoring_children(tracer->sighand)) {
+                                __wake_up_parent(p, tracer);
                                 p->exit_signal = -1;
+                        }
                 }
                 if (task_detached(p)) {
                         /* Mark it as in the process of being reaped. */
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index bd5d5c8e5140..400183346ad2 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -19,7 +19,7 @@
  *
  * Authors: Dipankar Sarma <dipankar@in.ibm.com>
  *          Manfred Spraul <manfred@colorfullife.com>
- * 
+ *
  * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
  * Papers:
@@ -27,7 +27,7 @@
  * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
  *
  * For detailed explanation of Read-Copy Update mechanism see -
- *              http://lse.sourceforge.net/locking/rcupdate.html
+ *              http://lse.sourceforge.net/locking/rcupdate.html
  *
  */
 #include <linux/types.h>
@@ -46,22 +46,15 @@
 #include <linux/module.h>
 #include <linux/kernel_stat.h>
 
-enum rcu_barrier {
-        RCU_BARRIER_STD,
-        RCU_BARRIER_BH,
-        RCU_BARRIER_SCHED,
-};
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_key;
+struct lockdep_map rcu_lock_map =
+        STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+EXPORT_SYMBOL_GPL(rcu_lock_map);
+#endif
 
-static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
-static atomic_t rcu_barrier_cpu_count;
-static DEFINE_MUTEX(rcu_barrier_mutex);
-static struct completion rcu_barrier_completion;
 int rcu_scheduler_active __read_mostly;
 
-static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
-static struct rcu_head rcu_migrate_head[3];
-static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);
-
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
  * grace period has elapsed.
@@ -74,6 +67,8 @@ void wakeme_after_rcu(struct rcu_head  *head)
         complete(&rcu->completion);
 }
 
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
 /**
  * synchronize_rcu - wait until a grace period has elapsed.
  *
@@ -87,7 +82,7 @@ void synchronize_rcu(void)
 {
         struct rcu_synchronize rcu;
 
-        if (rcu_blocking_is_gp())
+        if (!rcu_scheduler_active)
                 return;
 
         init_completion(&rcu.completion);
@@ -98,6 +93,46 @@ void synchronize_rcu(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu);
 
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
+/**
+ * synchronize_sched - wait until an rcu-sched grace period has elapsed.
+ *
+ * Control will return to the caller some time after a full rcu-sched
+ * grace period has elapsed, in other words after all currently executing
+ * rcu-sched read-side critical sections have completed.   These read-side
+ * critical sections are delimited by rcu_read_lock_sched() and
+ * rcu_read_unlock_sched(), and may be nested.  Note that preempt_disable(),
+ * local_irq_disable(), and so on may be used in place of
+ * rcu_read_lock_sched().
+ *
+ * This means that all preempt_disable code sequences, including NMI and
+ * hardware-interrupt handlers, in progress on entry will have completed
+ * before this primitive returns.  However, this does not guarantee that
+ * softirq handlers will have completed, since in some kernels, these
+ * handlers can run in process context, and can block.
+ *
+ * This primitive provides the guarantees made by the (now removed)
+ * synchronize_kernel() API.  In contrast, synchronize_rcu() only
+ * guarantees that rcu_read_lock() sections will have completed.
+ * In "classic RCU", these two guarantees happen to be one and
+ * the same, but can differ in realtime RCU implementations.
+ */
+void synchronize_sched(void)
+{
+        struct rcu_synchronize rcu;
+
+        if (rcu_blocking_is_gp())
+                return;
+
+        init_completion(&rcu.completion);
+        /* Will wake me after RCU finished. */
+        call_rcu_sched(&rcu.head, wakeme_after_rcu);
+        /* Wait for it. */
+        wait_for_completion(&rcu.completion);
+}
+EXPORT_SYMBOL_GPL(synchronize_sched);
+
 /**
  * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
  *
@@ -122,129 +157,10 @@ void synchronize_rcu_bh(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
 
-static void rcu_barrier_callback(struct rcu_head *notused)
-{
-        if (atomic_dec_and_test(&rcu_barrier_cpu_count))
-                complete(&rcu_barrier_completion);
-}
-
-/*
- * Called with preemption disabled, and from cross-cpu IRQ context.
- */
-static void rcu_barrier_func(void *type)
-{
-        int cpu = smp_processor_id();
-        struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
-
-        atomic_inc(&rcu_barrier_cpu_count);
-        switch ((enum rcu_barrier)type) {
-        case RCU_BARRIER_STD:
-                call_rcu(head, rcu_barrier_callback);
-                break;
-        case RCU_BARRIER_BH:
-                call_rcu_bh(head, rcu_barrier_callback);
-                break;
-        case RCU_BARRIER_SCHED:
-                call_rcu_sched(head, rcu_barrier_callback);
-                break;
-        }
-}
-
-static inline void wait_migrated_callbacks(void)
-{
-        wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
-        smp_mb(); /* In case we didn't sleep. */
-}
-
-/*
- * Orchestrate the specified type of RCU barrier, waiting for all
- * RCU callbacks of the specified type to complete.
- */
-static void _rcu_barrier(enum rcu_barrier type)
-{
-        BUG_ON(in_interrupt());
-        /* Take cpucontrol mutex to protect against CPU hotplug */
-        mutex_lock(&rcu_barrier_mutex);
-        init_completion(&rcu_barrier_completion);
-        /*
-         * Initialize rcu_barrier_cpu_count to 1, then invoke
-         * rcu_barrier_func() on each CPU, so that each CPU also has
-         * incremented rcu_barrier_cpu_count.  Only then is it safe to
-         * decrement rcu_barrier_cpu_count -- otherwise the first CPU
-         * might complete its grace period before all of the other CPUs
-         * did their increment, causing this function to return too
-         * early.
-         */
-        atomic_set(&rcu_barrier_cpu_count, 1);
-        on_each_cpu(rcu_barrier_func, (void *)type, 1);
-        if (atomic_dec_and_test(&rcu_barrier_cpu_count))
-                complete(&rcu_barrier_completion);
-        wait_for_completion(&rcu_barrier_completion);
-        mutex_unlock(&rcu_barrier_mutex);
-        wait_migrated_callbacks();
-}
-
-/**
- * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
- */
-void rcu_barrier(void)
-{
-        _rcu_barrier(RCU_BARRIER_STD);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier);
-
-/**
- * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
- */
-void rcu_barrier_bh(void)
-{
-        _rcu_barrier(RCU_BARRIER_BH);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_bh);
-
-/**
- * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
- */
-void rcu_barrier_sched(void)
-{
-        _rcu_barrier(RCU_BARRIER_SCHED);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_sched);
-
-static void rcu_migrate_callback(struct rcu_head *notused)
-{
-        if (atomic_dec_and_test(&rcu_migrate_type_count))
-                wake_up(&rcu_migrate_wq);
-}
-
-extern int rcu_cpu_notify(struct notifier_block *self,
-                          unsigned long action, void *hcpu);
-
 static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
                 unsigned long action, void *hcpu)
 {
-        rcu_cpu_notify(self, action, hcpu);
-        if (action == CPU_DYING) {
-                /*
-                 * preempt_disable() in on_each_cpu() prevents stop_machine(),
-                 * so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
-                 * returns, all online cpus have queued rcu_barrier_func(),
-                 * and the dead cpu(if it exist) queues rcu_migrate_callback()s.
-                 *
-                 * These callbacks ensure _rcu_barrier() waits for all
-                 * RCU callbacks of the specified type to complete.
-                 */
-                atomic_set(&rcu_migrate_type_count, 3);
-                call_rcu_bh(rcu_migrate_head, rcu_migrate_callback);
-                call_rcu_sched(rcu_migrate_head + 1, rcu_migrate_callback);
-                call_rcu(rcu_migrate_head + 2, rcu_migrate_callback);
-        } else if (action == CPU_DOWN_PREPARE) {
-                /* Don't need to wait until next removal operation. */
-                /* rcu_migrate_head is protected by cpu_add_remove_lock */
-                wait_migrated_callbacks();
-        }
-
-        return NOTIFY_OK;
+        return rcu_cpu_notify(self, action, hcpu);
 }
 
 void __init rcu_init(void)
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index b33db539a8ad..697c0a0229d4 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -18,7 +18,7 @@
  * Copyright (C) IBM Corporation, 2005, 2006
  *
  * Authors: Paul E. McKenney <paulmck@us.ibm.com>
- *          Josh Triplett <josh@freedesktop.org>
+ *        Josh Triplett <josh@freedesktop.org>
  *
  * See also:  Documentation/RCU/torture.txt
  */
@@ -50,7 +50,7 @@
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
-              "Josh Triplett <josh@freedesktop.org>");
+              "Josh Triplett <josh@freedesktop.org>");
 
 static int nreaders = -1;       /* # reader threads, defaults to 2*ncpus */
 static int nfakewriters = 4;    /* # fake writer threads */
@@ -110,8 +110,8 @@ struct rcu_torture {
 };
 
 static LIST_HEAD(rcu_torture_freelist);
-static struct rcu_torture *rcu_torture_current = NULL;
-static long rcu_torture_current_version = 0;
+static struct rcu_torture *rcu_torture_current;
+static long rcu_torture_current_version;
 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
 static DEFINE_SPINLOCK(rcu_torture_lock);
 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
@@ -124,11 +124,11 @@ static atomic_t n_rcu_torture_alloc_fail;
 static atomic_t n_rcu_torture_free;
 static atomic_t n_rcu_torture_mberror;
 static atomic_t n_rcu_torture_error;
-static long n_rcu_torture_timers = 0;
+static long n_rcu_torture_timers;
 static struct list_head rcu_torture_removed;
 static cpumask_var_t shuffle_tmp_mask;
 
-static int stutter_pause_test = 0;
+static int stutter_pause_test;
 
 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
 #define RCUTORTURE_RUNNABLE_INIT 1
@@ -267,7 +267,8 @@ struct rcu_torture_ops {
         int irq_capable;
         char *name;
 };
-static struct rcu_torture_ops *cur_ops = NULL;
+
+static struct rcu_torture_ops *cur_ops;
 
 /*
  * Definitions for rcu torture testing.
@@ -281,14 +282,17 @@ static int rcu_torture_read_lock(void) __acquires(RCU)
 
 static void rcu_read_delay(struct rcu_random_state *rrsp)
 {
-        long delay;
-        const long longdelay = 200;
+        const unsigned long shortdelay_us = 200;
+        const unsigned long longdelay_ms = 50;
 
-        /* We want there to be long-running readers, but not all the time. */
+        /* We want a short delay sometimes to make a reader delay the grace
+         * period, and we want a long delay occasionally to trigger
+         * force_quiescent_state. */
 
-        delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
-        if (!delay)
-                udelay(longdelay);
+        if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
+                mdelay(longdelay_ms);
+        if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
+                udelay(shortdelay_us);
 }
 
 static void rcu_torture_read_unlock(int idx) __releases(RCU)
@@ -339,8 +343,8 @@ static struct rcu_torture_ops rcu_ops = {
         .sync           = synchronize_rcu,
         .cb_barrier     = rcu_barrier,
         .stats          = NULL,
-        .irq_capable    = 1,
-        .name           = "rcu"
+        .irq_capable    = 1,
+        .name           = "rcu"
 };
 
 static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
@@ -602,8 +606,6 @@ static struct rcu_torture_ops sched_ops_sync = {
         .name           = "sched_sync"
 };
 
-extern int rcu_expedited_torture_stats(char *page);
-
 static struct rcu_torture_ops sched_expedited_ops = {
         .init           = rcu_sync_torture_init,
         .cleanup        = NULL,
@@ -638,14 +640,15 @@ rcu_torture_writer(void *arg)
 
         do {
                 schedule_timeout_uninterruptible(1);
-                if ((rp = rcu_torture_alloc()) == NULL)
+                rp = rcu_torture_alloc();
+                if (rp == NULL)
                         continue;
                 rp->rtort_pipe_count = 0;
                 udelay(rcu_random(&rand) & 0x3ff);
                 old_rp = rcu_torture_current;
                 rp->rtort_mbtest = 1;
                 rcu_assign_pointer(rcu_torture_current, rp);
-                smp_wmb();
+                smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
                 if (old_rp) {
                         i = old_rp->rtort_pipe_count;
                         if (i > RCU_TORTURE_PIPE_LEN)
@@ -1110,7 +1113,7 @@ rcu_torture_init(void)
                 printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
                        torture_type);
                 mutex_unlock(&fullstop_mutex);
-                return (-EINVAL);
+                return -EINVAL;
         }
         if (cur_ops->init)
                 cur_ops->init(); /* no "goto unwind" prior to this point!!! */
@@ -1161,7 +1164,7 @@ rcu_torture_init(void)
                 goto unwind;
         }
         fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
-                                   GFP_KERNEL);
+                                   GFP_KERNEL);
         if (fakewriter_tasks == NULL) {
                 VERBOSE_PRINTK_ERRSTRING("out of memory");
                 firsterr = -ENOMEM;
@@ -1170,7 +1173,7 @@ rcu_torture_init(void)
         for (i = 0; i < nfakewriters; i++) {
                 VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
                 fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
-                                                  "rcu_torture_fakewriter");
+                                                  "rcu_torture_fakewriter");
                 if (IS_ERR(fakewriter_tasks[i])) {
                         firsterr = PTR_ERR(fakewriter_tasks[i]);
                         VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 6b11b07cfe7f..705f02ac7433 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -25,7 +25,7 @@
  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
  *
  * For detailed explanation of Read-Copy Update mechanism see -
- *      Documentation/RCU
+ *      Documentation/RCU
  */
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -49,13 +49,6 @@
 
 #include "rcutree.h"
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static struct lock_class_key rcu_lock_key;
-struct lockdep_map rcu_lock_map =
-        STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
-EXPORT_SYMBOL_GPL(rcu_lock_map);
-#endif
-
 /* Data structures. */
 
 #define RCU_STATE_INITIALIZER(name) { \
@@ -70,6 +63,9 @@ EXPORT_SYMBOL_GPL(rcu_lock_map);
         .gpnum = -300, \
         .completed = -300, \
         .onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
+        .orphan_cbs_list = NULL, \
+        .orphan_cbs_tail = &name.orphan_cbs_list, \
+        .orphan_qlen = 0, \
         .fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \
         .n_force_qs = 0, \
         .n_force_qs_ngp = 0, \
@@ -81,24 +77,16 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
 struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
 DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
 
-extern long rcu_batches_completed_sched(void);
-static struct rcu_node *rcu_get_root(struct rcu_state *rsp);
-static void cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp,
-                          struct rcu_node *rnp, unsigned long flags);
-static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags);
-#ifdef CONFIG_HOTPLUG_CPU
-static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp);
-#endif /* #ifdef CONFIG_HOTPLUG_CPU */
-static void __rcu_process_callbacks(struct rcu_state *rsp,
-                                    struct rcu_data *rdp);
-static void __call_rcu(struct rcu_head *head,
-                       void (*func)(struct rcu_head *rcu),
-                       struct rcu_state *rsp);
-static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp);
-static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp,
-                                           int preemptable);
 
-#include "rcutree_plugin.h"
+/*
+ * Return true if an RCU grace period is in progress.  The ACCESS_ONCE()s
+ * permit this function to be invoked without holding the root rcu_node
+ * structure's ->lock, but of course results can be subject to change.
+ */
+static int rcu_gp_in_progress(struct rcu_state *rsp)
+{
+        return ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum);
+}
 
 /*
  * Note a quiescent state.  Because we do not need to know
@@ -107,27 +95,23 @@ static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp,
  */
 void rcu_sched_qs(int cpu)
 {
-        unsigned long flags;
         struct rcu_data *rdp;
 
-        local_irq_save(flags);
         rdp = &per_cpu(rcu_sched_data, cpu);
-        rdp->passed_quiesc = 1;
         rdp->passed_quiesc_completed = rdp->completed;
-        rcu_preempt_qs(cpu);
-        local_irq_restore(flags);
+        barrier();
+        rdp->passed_quiesc = 1;
+        rcu_preempt_note_context_switch(cpu);
 }
 
 void rcu_bh_qs(int cpu)
 {
-        unsigned long flags;
         struct rcu_data *rdp;
 
-        local_irq_save(flags);
         rdp = &per_cpu(rcu_bh_data, cpu);
-        rdp->passed_quiesc = 1;
         rdp->passed_quiesc_completed = rdp->completed;
-        local_irq_restore(flags);
+        barrier();
+        rdp->passed_quiesc = 1;
 }
 
 #ifdef CONFIG_NO_HZ
@@ -141,6 +125,10 @@ static int blimit = 10;		/* Maximum callbacks per softirq. */
 static int qhimark = 10000;     /* If this many pending, ignore blimit. */
 static int qlowmark = 100;      /* Once only this many pending, use blimit. */
 
+module_param(blimit, int, 0);
+module_param(qhimark, int, 0);
+module_param(qlowmark, int, 0);
+
 static void force_quiescent_state(struct rcu_state *rsp, int relaxed);
 static int rcu_pending(int cpu);
 
@@ -177,9 +165,7 @@ cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp)
 static int
 cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
 {
-        /* ACCESS_ONCE() because we are accessing outside of lock. */
-        return *rdp->nxttail[RCU_DONE_TAIL] &&
-               ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum);
+        return *rdp->nxttail[RCU_DONE_TAIL] && !rcu_gp_in_progress(rsp);
 }
 
 /*
@@ -373,7 +359,7 @@ static long dyntick_recall_completed(struct rcu_state *rsp)
 /*
  * Snapshot the specified CPU's dynticks counter so that we can later
  * credit them with an implicit quiescent state.  Return 1 if this CPU
- * is already in a quiescent state courtesy of dynticks idle mode.
+ * is in dynticks idle mode, which is an extended quiescent state.
  */
 static int dyntick_save_progress_counter(struct rcu_data *rdp)
 {
@@ -479,30 +465,34 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
         long delta;
         unsigned long flags;
         struct rcu_node *rnp = rcu_get_root(rsp);
-        struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
-        struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
 
         /* Only let one CPU complain about others per time interval. */
 
         spin_lock_irqsave(&rnp->lock, flags);
         delta = jiffies - rsp->jiffies_stall;
-        if (delta < RCU_STALL_RAT_DELAY || rsp->gpnum == rsp->completed) {
+        if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
                 spin_unlock_irqrestore(&rnp->lock, flags);
                 return;
         }
         rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
+
+        /*
+         * Now rat on any tasks that got kicked up to the root rcu_node
+         * due to CPU offlining.
+         */
+        rcu_print_task_stall(rnp);
         spin_unlock_irqrestore(&rnp->lock, flags);
 
         /* OK, time to rat on our buddy... */
 
         printk(KERN_ERR "INFO: RCU detected CPU stalls:");
-        for (; rnp_cur < rnp_end; rnp_cur++) {
+        rcu_for_each_leaf_node(rsp, rnp) {
                 rcu_print_task_stall(rnp);
-                if (rnp_cur->qsmask == 0)
+                if (rnp->qsmask == 0)
                         continue;
-                for (cpu = 0; cpu <= rnp_cur->grphi - rnp_cur->grplo; cpu++)
-                        if (rnp_cur->qsmask & (1UL << cpu))
-                                printk(" %d", rnp_cur->grplo + cpu);
+                for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
+                        if (rnp->qsmask & (1UL << cpu))
+                                printk(" %d", rnp->grplo + cpu);
         }
         printk(" (detected by %d, t=%ld jiffies)\n",
                smp_processor_id(), (long)(jiffies - rsp->gp_start));
@@ -541,8 +531,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
                 /* We haven't checked in, so go dump stack. */
                 print_cpu_stall(rsp);
 
-        } else if (rsp->gpnum != rsp->completed &&
-                   delta >= RCU_STALL_RAT_DELAY) {
+        } else if (rcu_gp_in_progress(rsp) && delta >= RCU_STALL_RAT_DELAY) {
 
                 /* They had two time units to dump stack, so complain. */
                 print_other_cpu_stall(rsp);
@@ -605,8 +594,6 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 {
         struct rcu_data *rdp = rsp->rda[smp_processor_id()];
         struct rcu_node *rnp = rcu_get_root(rsp);
-        struct rcu_node *rnp_cur;
-        struct rcu_node *rnp_end;
 
         if (!cpu_needs_another_gp(rsp, rdp)) {
                 spin_unlock_irqrestore(&rnp->lock, flags);
@@ -615,6 +602,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 
         /* Advance to a new grace period and initialize state. */
         rsp->gpnum++;
+        WARN_ON_ONCE(rsp->signaled == RCU_GP_INIT);
         rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
         rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
         record_gp_stall_check_time(rsp);
@@ -622,16 +610,24 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
         note_new_gpnum(rsp, rdp);
 
         /*
-         * Because we are first, we know that all our callbacks will
-         * be covered by this upcoming grace period, even the ones
-         * that were registered arbitrarily recently.
+         * Because this CPU just now started the new grace period, we know
+         * that all of its callbacks will be covered by this upcoming grace
+         * period, even the ones that were registered arbitrarily recently.
+         * Therefore, advance all outstanding callbacks to RCU_WAIT_TAIL.
+         *
+         * Other CPUs cannot be sure exactly when the grace period started.
+         * Therefore, their recently registered callbacks must pass through
+         * an additional RCU_NEXT_READY stage, so that they will be handled
+         * by the next RCU grace period.
          */
         rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
         rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 
         /* Special-case the common single-level case. */
         if (NUM_RCU_NODES == 1) {
+                rcu_preempt_check_blocked_tasks(rnp);
                 rnp->qsmask = rnp->qsmaskinit;
+                rnp->gpnum = rsp->gpnum;
                 rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */
                 spin_unlock_irqrestore(&rnp->lock, flags);
                 return;
@@ -644,42 +640,28 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
         spin_lock(&rsp->onofflock);  /* irqs already disabled. */
 
         /*
-         * Set the quiescent-state-needed bits in all the non-leaf RCU
-         * nodes for all currently online CPUs.  This operation relies
-         * on the layout of the hierarchy within the rsp->node[] array.
-         * Note that other CPUs will access only the leaves of the
-         * hierarchy, which still indicate that no grace period is in
-         * progress.  In addition, we have excluded CPU-hotplug operations.
-         *
-         * We therefore do not need to hold any locks.  Any required
-         * memory barriers will be supplied by the locks guarding the
-         * leaf rcu_nodes in the hierarchy.
-         */
-
-        rnp_end = rsp->level[NUM_RCU_LVLS - 1];
-        for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++)
-                rnp_cur->qsmask = rnp_cur->qsmaskinit;
-
-        /*
-         * Now set up the leaf nodes.  Here we must be careful.  First,
-         * we need to hold the lock in order to exclude other CPUs, which
-         * might be contending for the leaf nodes' locks.  Second, as
-         * soon as we initialize a given leaf node, its CPUs might run
-         * up the rest of the hierarchy.  We must therefore acquire locks
-         * for each node that we touch during this stage.  (But we still
-         * are excluding CPU-hotplug operations.)
+         * Set the quiescent-state-needed bits in all the rcu_node
+         * structures for all currently online CPUs in breadth-first
+         * order, starting from the root rcu_node structure.  This
+         * operation relies on the layout of the hierarchy within the
+         * rsp->node[] array.  Note that other CPUs will access only
+         * the leaves of the hierarchy, which still indicate that no
+         * grace period is in progress, at least until the corresponding
+         * leaf node has been initialized.  In addition, we have excluded
+         * CPU-hotplug operations.
          *
          * Note that the grace period cannot complete until we finish
          * the initialization process, as there will be at least one
          * qsmask bit set in the root node until that time, namely the
-         * one corresponding to this CPU.
+         * one corresponding to this CPU, due to the fact that we have
+         * irqs disabled.
          */
-        rnp_end = &rsp->node[NUM_RCU_NODES];
-        rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
-        for (; rnp_cur < rnp_end; rnp_cur++) {
-                spin_lock(&rnp_cur->lock);      /* irqs already disabled. */
-                rnp_cur->qsmask = rnp_cur->qsmaskinit;
-                spin_unlock(&rnp_cur->lock);    /* irqs already disabled. */
+        rcu_for_each_node_breadth_first(rsp, rnp) {
+                spin_lock(&rnp->lock);  /* irqs already disabled. */
+                rcu_preempt_check_blocked_tasks(rnp);
+                rnp->qsmask = rnp->qsmaskinit;
+                rnp->gpnum = rsp->gpnum;
+                spin_unlock(&rnp->lock);        /* irqs already disabled. */
         }
 
         rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */
@@ -720,8 +702,9 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
  * hold rnp->lock, as required by rcu_start_gp(), which will release it.
  */
 static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
-        __releases(rnp->lock)
+        __releases(rcu_get_root(rsp)->lock)
 {
+        WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
         rsp->completed = rsp->gpnum;
         rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
         rcu_start_gp(rsp, flags);  /* releases root node's rnp->lock. */
@@ -739,6 +722,8 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
               unsigned long flags)
         __releases(rnp->lock)
 {
+        struct rcu_node *rnp_c;
+
         /* Walk up the rcu_node hierarchy. */
         for (;;) {
                 if (!(rnp->qsmask & mask)) {
@@ -762,8 +747,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
                         break;
                 }
                 spin_unlock_irqrestore(&rnp->lock, flags);
+                rnp_c = rnp;
                 rnp = rnp->parent;
                 spin_lock_irqsave(&rnp->lock, flags);
+                WARN_ON_ONCE(rnp_c->qsmask);
         }
 
         /*
@@ -776,10 +763,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
 
 /*
  * Record a quiescent state for the specified CPU, which must either be
- * the current CPU or an offline CPU.  The lastcomp argument is used to
- * make sure we are still in the grace period of interest.  We don't want
- * to end the current grace period based on quiescent states detected in
- * an earlier grace period!
+ * the current CPU.  The lastcomp argument is used to make sure we are
+ * still in the grace period of interest.  We don't want to end the current
+ * grace period based on quiescent states detected in an earlier grace
+ * period!
  */
 static void
 cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
@@ -814,7 +801,6 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
                  * This GP can't end until cpu checks in, so all of our
                  * callbacks can be processed during the next GP.
                  */
-                rdp = rsp->rda[smp_processor_id()];
                 rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 
                 cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */
@@ -855,24 +841,70 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
 #ifdef CONFIG_HOTPLUG_CPU
 
 /*
+ * Move a dying CPU's RCU callbacks to the ->orphan_cbs_list for the
+ * specified flavor of RCU.  The callbacks will be adopted by the next
+ * _rcu_barrier() invocation or by the CPU_DEAD notifier, whichever
+ * comes first.  Because this is invoked from the CPU_DYING notifier,
+ * irqs are already disabled.
+ */
+static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
+{
+        int i;
+        struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+
+        if (rdp->nxtlist == NULL)
+                return;  /* irqs disabled, so comparison is stable. */
+        spin_lock(&rsp->onofflock);  /* irqs already disabled. */
+        *rsp->orphan_cbs_tail = rdp->nxtlist;
+        rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL];
+        rdp->nxtlist = NULL;
+        for (i = 0; i < RCU_NEXT_SIZE; i++)
+                rdp->nxttail[i] = &rdp->nxtlist;
+        rsp->orphan_qlen += rdp->qlen;
+        rdp->qlen = 0;
+        spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */
+}
+
+/*
+ * Adopt previously orphaned RCU callbacks.
+ */
+static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
+{
+        unsigned long flags;
+        struct rcu_data *rdp;
+
+        spin_lock_irqsave(&rsp->onofflock, flags);
+        rdp = rsp->rda[smp_processor_id()];
+        if (rsp->orphan_cbs_list == NULL) {
+                spin_unlock_irqrestore(&rsp->onofflock, flags);
+                return;
+        }
+        *rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
+        rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_tail;
+        rdp->qlen += rsp->orphan_qlen;
+        rsp->orphan_cbs_list = NULL;
+        rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;
+        rsp->orphan_qlen = 0;
+        spin_unlock_irqrestore(&rsp->onofflock, flags);
+}
+
+/*
  * Remove the outgoing CPU from the bitmasks in the rcu_node hierarchy
  * and move all callbacks from the outgoing CPU to the current one.
  */
 static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
 {
-        int i;
         unsigned long flags;
         long lastcomp;
         unsigned long mask;
         struct rcu_data *rdp = rsp->rda[cpu];
-        struct rcu_data *rdp_me;
         struct rcu_node *rnp;
 
         /* Exclude any attempts to start a new grace period. */
         spin_lock_irqsave(&rsp->onofflock, flags);
 
         /* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */
-        rnp = rdp->mynode;
+        rnp = rdp->mynode;      /* this is the outgoing CPU's rnp. */
         mask = rdp->grpmask;    /* rnp->grplo is constant. */
         do {
                 spin_lock(&rnp->lock);          /* irqs already disabled. */
@@ -881,42 +913,16 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
                         spin_unlock(&rnp->lock); /* irqs remain disabled. */
                         break;
                 }
-                rcu_preempt_offline_tasks(rsp, rnp);
+                rcu_preempt_offline_tasks(rsp, rnp, rdp);
                 mask = rnp->grpmask;
                 spin_unlock(&rnp->lock);        /* irqs remain disabled. */
                 rnp = rnp->parent;
         } while (rnp != NULL);
         lastcomp = rsp->completed;
 
-        spin_unlock(&rsp->onofflock);           /* irqs remain disabled. */
-
-        /* Being offline is a quiescent state, so go record it. */
-        cpu_quiet(cpu, rsp, rdp, lastcomp);
+        spin_unlock_irqrestore(&rsp->onofflock, flags);
 
-        /*
-         * Move callbacks from the outgoing CPU to the running CPU.
-         * Note that the outgoing CPU is now quiscent, so it is now
-         * (uncharacteristically) safe to access its rcu_data structure.
-         * Note also that we must carefully retain the order of the
-         * outgoing CPU's callbacks in order for rcu_barrier() to work
-         * correctly.  Finally, note that we start all the callbacks
-         * afresh, even those that have passed through a grace period
-         * and are therefore ready to invoke.  The theory is that hotplug
-         * events are rare, and that if they are frequent enough to
-         * indefinitely delay callbacks, you have far worse things to
-         * be worrying about.
-         */
-        rdp_me = rsp->rda[smp_processor_id()];
-        if (rdp->nxtlist != NULL) {
-                *rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxtlist;
-                rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
-                rdp->nxtlist = NULL;
-                for (i = 0; i < RCU_NEXT_SIZE; i++)
-                        rdp->nxttail[i] = &rdp->nxtlist;
-                rdp_me->qlen += rdp->qlen;
-                rdp->qlen = 0;
-        }
-        local_irq_restore(flags);
+        rcu_adopt_orphan_cbs(rsp);
 }
 
 /*
@@ -934,6 +940,14 @@ static void rcu_offline_cpu(int cpu)
 
 #else /* #ifdef CONFIG_HOTPLUG_CPU */
 
+static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
+{
+}
+
+static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
+{
+}
+
 static void rcu_offline_cpu(int cpu)
 {
 }
@@ -1066,33 +1080,32 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
         int cpu;
         unsigned long flags;
         unsigned long mask;
-        struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
-        struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
+        struct rcu_node *rnp;
 
-        for (; rnp_cur < rnp_end; rnp_cur++) {
+        rcu_for_each_leaf_node(rsp, rnp) {
                 mask = 0;
-                spin_lock_irqsave(&rnp_cur->lock, flags);
+                spin_lock_irqsave(&rnp->lock, flags);
                 if (rsp->completed != lastcomp) {
-                        spin_unlock_irqrestore(&rnp_cur->lock, flags);
+                        spin_unlock_irqrestore(&rnp->lock, flags);
                         return 1;
                 }
-                if (rnp_cur->qsmask == 0) {
-                        spin_unlock_irqrestore(&rnp_cur->lock, flags);
+                if (rnp->qsmask == 0) {
+                        spin_unlock_irqrestore(&rnp->lock, flags);
                         continue;
                 }
-                cpu = rnp_cur->grplo;
+                cpu = rnp->grplo;
                 bit = 1;
-                for (; cpu <= rnp_cur->grphi; cpu++, bit <<= 1) {
-                        if ((rnp_cur->qsmask & bit) != 0 && f(rsp->rda[cpu]))
+                for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
+                        if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu]))
                                 mask |= bit;
                 }
                 if (mask != 0 && rsp->completed == lastcomp) {
 
-                        /* cpu_quiet_msk() releases rnp_cur->lock. */
-                        cpu_quiet_msk(mask, rsp, rnp_cur, flags);
+                        /* cpu_quiet_msk() releases rnp->lock. */
+                        cpu_quiet_msk(mask, rsp, rnp, flags);
                         continue;
                 }
-                spin_unlock_irqrestore(&rnp_cur->lock, flags);
+                spin_unlock_irqrestore(&rnp->lock, flags);
         }
         return 0;
 }
@@ -1108,7 +1121,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
         struct rcu_node *rnp = rcu_get_root(rsp);
         u8 signaled;
 
-        if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum))
+        if (!rcu_gp_in_progress(rsp))
                 return;  /* No grace period in progress, nothing to force. */
         if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {
                 rsp->n_force_qs_lh++; /* Inexact, can lose counts.  Tough! */
@@ -1267,7 +1280,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
         rdp->nxttail[RCU_NEXT_TAIL] = &head->next;
 
         /* Start a new grace period if one not already started. */
-        if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum)) {
+        if (!rcu_gp_in_progress(rsp)) {
                 unsigned long nestflag;
                 struct rcu_node *rnp_root = rcu_get_root(rsp);
 
@@ -1347,7 +1360,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
         }
 
         /* Has an RCU GP gone long enough to send resched IPIs &c? */
-        if (ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum) &&
+        if (rcu_gp_in_progress(rsp) &&
             ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) {
                 rdp->n_rp_need_fqs++;
                 return 1;
@@ -1384,6 +1397,82 @@ int rcu_needs_cpu(int cpu)
                rcu_preempt_needs_cpu(cpu);
 }
 
+static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
+static atomic_t rcu_barrier_cpu_count;
+static DEFINE_MUTEX(rcu_barrier_mutex);
+static struct completion rcu_barrier_completion;
+
+static void rcu_barrier_callback(struct rcu_head *notused)
+{
+        if (atomic_dec_and_test(&rcu_barrier_cpu_count))
+                complete(&rcu_barrier_completion);
+}
+
+/*
+ * Called with preemption disabled, and from cross-cpu IRQ context.
+ */
+static void rcu_barrier_func(void *type)
+{
+        int cpu = smp_processor_id();
+        struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
+        void (*call_rcu_func)(struct rcu_head *head,
+                              void (*func)(struct rcu_head *head));
+
+        atomic_inc(&rcu_barrier_cpu_count);
+        call_rcu_func = type;
+        call_rcu_func(head, rcu_barrier_callback);
+}
+
+/*
+ * Orchestrate the specified type of RCU barrier, waiting for all
+ * RCU callbacks of the specified type to complete.
+ */
+static void _rcu_barrier(struct rcu_state *rsp,
+                         void (*call_rcu_func)(struct rcu_head *head,
+                                               void (*func)(struct rcu_head *head)))
+{
+        BUG_ON(in_interrupt());
+        /* Take mutex to serialize concurrent rcu_barrier() requests. */
+        mutex_lock(&rcu_barrier_mutex);
+        init_completion(&rcu_barrier_completion);
+        /*
+         * Initialize rcu_barrier_cpu_count to 1, then invoke
+         * rcu_barrier_func() on each CPU, so that each CPU also has
+         * incremented rcu_barrier_cpu_count.  Only then is it safe to
+         * decrement rcu_barrier_cpu_count -- otherwise the first CPU
+         * might complete its grace period before all of the other CPUs
+         * did their increment, causing this function to return too
+         * early.
+         */
+        atomic_set(&rcu_barrier_cpu_count, 1);
+        preempt_disable(); /* stop CPU_DYING from filling orphan_cbs_list */
+        rcu_adopt_orphan_cbs(rsp);
+        on_each_cpu(rcu_barrier_func, (void *)call_rcu_func, 1);
+        preempt_enable(); /* CPU_DYING can again fill orphan_cbs_list */
+        if (atomic_dec_and_test(&rcu_barrier_cpu_count))
+                complete(&rcu_barrier_completion);
+        wait_for_completion(&rcu_barrier_completion);
+        mutex_unlock(&rcu_barrier_mutex);
+}
+
+/**
+ * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
+ */
+void rcu_barrier_bh(void)
+{
+        _rcu_barrier(&rcu_bh_state, call_rcu_bh);
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_bh);
+
+/**
+ * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
+ */
+void rcu_barrier_sched(void)
+{
+        _rcu_barrier(&rcu_sched_state, call_rcu_sched);
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_sched);
+
 /*
  * Do boot-time initialization of a CPU's per-CPU RCU data.
  */
@@ -1457,20 +1546,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
                 rnp = rnp->parent;
         } while (rnp != NULL && !(rnp->qsmaskinit & mask));
 
-        spin_unlock(&rsp->onofflock);           /* irqs remain disabled. */
-
-        /*
-         * A new grace period might start here.  If so, we will be part of
-         * it, and its gpnum will be greater than ours, so we will
-         * participate.  It is also possible for the gpnum to have been
-         * incremented before this function was called, and the bitmasks
-         * to not be filled out until now, in which case we will also
-         * participate due to our gpnum being behind.
-         */
-
-        /* Since it is coming online, the CPU is in a quiescent state. */
-        cpu_quiet(cpu, rsp, rdp, lastcomp);
-        local_irq_restore(flags);
+        spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
 static void __cpuinit rcu_online_cpu(int cpu)
@@ -1493,6 +1569,22 @@ int __cpuinit rcu_cpu_notify(struct notifier_block *self,
         case CPU_UP_PREPARE_FROZEN:
                 rcu_online_cpu(cpu);
                 break;
+        case CPU_DYING:
+        case CPU_DYING_FROZEN:
+                /*
+                 * preempt_disable() in _rcu_barrier() prevents stop_machine(),
+                 * so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
+                 * returns, all online cpus have queued rcu_barrier_func().
+                 * The dying CPU clears its cpu_online_mask bit and
+                 * moves all of its RCU callbacks to ->orphan_cbs_list
+                 * in the context of stop_machine(), so subsequent calls
+                 * to _rcu_barrier() will adopt these callbacks and only
+                 * then queue rcu_barrier_func() on all remaining CPUs.
+                 */
+                rcu_send_cbs_to_orphanage(&rcu_bh_state);
+                rcu_send_cbs_to_orphanage(&rcu_sched_state);
+                rcu_preempt_send_cbs_to_orphanage();
+                break;
         case CPU_DEAD:
         case CPU_DEAD_FROZEN:
         case CPU_UP_CANCELED:
@@ -1555,7 +1647,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
                 cpustride *= rsp->levelspread[i];
                 rnp = rsp->level[i];
                 for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
-                        spin_lock_init(&rnp->lock);
+                        if (rnp != rcu_get_root(rsp))
+                                spin_lock_init(&rnp->lock);
                         rnp->gpnum = 0;
                         rnp->qsmask = 0;
                         rnp->qsmaskinit = 0;
@@ -1578,6 +1671,7 @@ static void __init rcu_init_one(struct rcu_state *rsp)
                         INIT_LIST_HEAD(&rnp->blocked_tasks[1]);
                 }
         }
+        spin_lock_init(&rcu_get_root(rsp)->lock);
 }
 
 /*
@@ -1587,6 +1681,10 @@ static void __init rcu_init_one(struct rcu_state *rsp)
  */
 #define RCU_INIT_FLAVOR(rsp, rcu_data) \
 do { \
+        int i; \
+        int j; \
+        struct rcu_node *rnp; \
+        \
         rcu_init_one(rsp); \
         rnp = (rsp)->level[NUM_RCU_LVLS - 1]; \
         j = 0; \
@@ -1599,31 +1697,8 @@ do { \
         } \
 } while (0)
 
-#ifdef CONFIG_TREE_PREEMPT_RCU
-
-void __init __rcu_init_preempt(void)
-{
-        int i;                  /* All used by RCU_INIT_FLAVOR(). */
-        int j;
-        struct rcu_node *rnp;
-
-        RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
-}
-
-#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
-
-void __init __rcu_init_preempt(void)
-{
-}
-
-#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
-
 void __init __rcu_init(void)
 {
-        int i;                  /* All used by RCU_INIT_FLAVOR(). */
-        int j;
-        struct rcu_node *rnp;
-
         rcu_bootup_announce();
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
         printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
@@ -1634,6 +1709,4 @@ void __init __rcu_init(void)
         open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
 }
 
-module_param(blimit, int, 0);
-module_param(qhimark, int, 0);
-module_param(qlowmark, int, 0);
+#include "rcutree_plugin.h"
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index bf8a6f9f134d..b40ac5706040 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -48,14 +48,14 @@
 #elif NR_CPUS <= RCU_FANOUT_SQ
 #  define NUM_RCU_LVLS        2
 #  define NUM_RCU_LVL_0       1
-#  define NUM_RCU_LVL_1       (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)
+#  define NUM_RCU_LVL_1       DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
 #  define NUM_RCU_LVL_2       (NR_CPUS)
 #  define NUM_RCU_LVL_3       0
 #elif NR_CPUS <= RCU_FANOUT_CUBE
 #  define NUM_RCU_LVLS        3
 #  define NUM_RCU_LVL_0       1
-#  define NUM_RCU_LVL_1       (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)
-#  define NUM_RCU_LVL_2       (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))
+#  define NUM_RCU_LVL_1       DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_SQ)
+#  define NUM_RCU_LVL_2       DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
 #  define NUM_RCU_LVL_3       NR_CPUS
 #else
 # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
@@ -79,15 +79,21 @@ struct rcu_dynticks {
  * Definition for node within the RCU grace-period-detection hierarchy.
  */
 struct rcu_node {
-        spinlock_t lock;
+        spinlock_t lock;        /* Root rcu_node's lock protects some */
+                                /*  rcu_state fields as well as following. */
         long    gpnum;          /* Current grace period for this node. */
                                 /*  This will either be equal to or one */
                                 /*  behind the root rcu_node's gpnum. */
         unsigned long qsmask;   /* CPUs or groups that need to switch in */
                                 /*  order for current grace period to proceed.*/
+                                /*  In leaf rcu_node, each bit corresponds to */
+                                /*  an rcu_data structure, otherwise, each */
+                                /*  bit corresponds to a child rcu_node */
+                                /*  structure. */
         unsigned long qsmaskinit;
                                 /* Per-GP initialization for qsmask. */
         unsigned long grpmask;  /* Mask to apply to parent qsmask. */
+                                /*  Only one bit will be set in this mask. */
         int     grplo;          /* lowest-numbered CPU or group here. */
         int     grphi;          /* highest-numbered CPU or group here. */
         u8      grpnum;         /* CPU/group number for next level up. */
@@ -95,8 +101,23 @@ struct rcu_node {
         struct rcu_node *parent;
         struct list_head blocked_tasks[2];
                                 /* Tasks blocked in RCU read-side critsect. */
+                                /*  Grace period number (->gpnum) x blocked */
+                                /*  by tasks on the (x & 0x1) element of the */
+                                /*  blocked_tasks[] array. */
 } ____cacheline_internodealigned_in_smp;
 
+/*
+ * Do a full breadth-first scan of the rcu_node structures for the
+ * specified rcu_state structure.
+ */
+#define rcu_for_each_node_breadth_first(rsp, rnp) \
+        for ((rnp) = &(rsp)->node[0]; \
+             (rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++)
+
+#define rcu_for_each_leaf_node(rsp, rnp) \
+        for ((rnp) = (rsp)->level[NUM_RCU_LVLS - 1]; \
+             (rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++)
+
 /* Index values for nxttail array in struct rcu_data. */
 #define RCU_DONE_TAIL           0       /* Also RCU_WAIT head. */
 #define RCU_WAIT_TAIL           1       /* Also RCU_NEXT_READY head. */
@@ -126,23 +147,26 @@ struct rcu_data {
          * Any of the partitions might be empty, in which case the
          * pointer to that partition will be equal to the pointer for
          * the following partition.  When the list is empty, all of
-         * the nxttail elements point to nxtlist, which is NULL.
+         * the nxttail elements point to the ->nxtlist pointer itself,
+         * which in that case is NULL.
          *
-         * [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):
-         *      Entries that might have arrived after current GP ended
-         * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
-         *      Entries known to have arrived before current GP ended
-         * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
-         *      Entries that batch # <= ->completed - 1: waiting for current GP
          * [nxtlist, *nxttail[RCU_DONE_TAIL]):
          *      Entries that batch # <= ->completed
          *      The grace period for these entries has completed, and
          *      the other grace-period-completed entries may be moved
          *      here temporarily in rcu_process_callbacks().
+         * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
+         *      Entries that batch # <= ->completed - 1: waiting for current GP
+         * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
+         *      Entries known to have arrived before current GP ended
+         * [*nxttail[RCU_NEXT_READY_TAIL], *nxttail[RCU_NEXT_TAIL]):
+         *      Entries that might have arrived after current GP ended
+         *      Note that the value of *nxttail[RCU_NEXT_TAIL] will
+         *      always be NULL, as this is the end of the list.
          */
         struct rcu_head *nxtlist;
         struct rcu_head **nxttail[RCU_NEXT_SIZE];
-        long            qlen;           /* # of queued callbacks */
+        long            qlen;           /* # of queued callbacks */
         long            blimit;         /* Upper limit on a processed batch */
 
 #ifdef CONFIG_NO_HZ
@@ -216,8 +240,19 @@ struct rcu_state {
                                                 /* Force QS state. */
         long    gpnum;                          /* Current gp number. */
         long    completed;                      /* # of last completed gp. */
+
+        /* End  of fields guarded by root rcu_node's lock. */
+
         spinlock_t onofflock;                   /* exclude on/offline and */
-                                                /*  starting new GP. */
+                                                /*  starting new GP.  Also */
+                                                /*  protects the following */
+                                                /*  orphan_cbs fields. */
+        struct rcu_head *orphan_cbs_list;       /* list of rcu_head structs */
+                                                /*  orphaned by all CPUs in */
+                                                /*  a given leaf rcu_node */
+                                                /*  going offline. */
+        struct rcu_head **orphan_cbs_tail;      /* And tail pointer. */
+        long orphan_qlen;                       /* Number of orphaned cbs. */
         spinlock_t fqslock;                     /* Only one task forcing */
                                                 /*  quiescent states. */
         unsigned long jiffies_force_qs;         /* Time at which to invoke */
@@ -255,5 +290,30 @@ extern struct rcu_state rcu_preempt_state;
 DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 
-#endif /* #ifdef RCU_TREE_NONCORE */
+#else /* #ifdef RCU_TREE_NONCORE */
+
+/* Forward declarations for rcutree_plugin.h */
+static inline void rcu_bootup_announce(void);
+long rcu_batches_completed(void);
+static void rcu_preempt_note_context_switch(int cpu);
+static int rcu_preempted_readers(struct rcu_node *rnp);
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+static void rcu_print_task_stall(struct rcu_node *rnp);
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
+#ifdef CONFIG_HOTPLUG_CPU
+static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
+                                      struct rcu_node *rnp,
+                                      struct rcu_data *rdp);
+static void rcu_preempt_offline_cpu(int cpu);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+static void rcu_preempt_check_callbacks(int cpu);
+static void rcu_preempt_process_callbacks(void);
+void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
+static int rcu_preempt_pending(int cpu);
+static int rcu_preempt_needs_cpu(int cpu);
+static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
+static void rcu_preempt_send_cbs_to_orphanage(void);
+static void __init __rcu_init_preempt(void);
 
+#endif /* #else #ifdef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 47789369ea59..c0cb783aa16a 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -64,22 +64,31 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed);
  * not in a quiescent state.  There might be any number of tasks blocked
  * while in an RCU read-side critical section.
  */
-static void rcu_preempt_qs_record(int cpu)
+static void rcu_preempt_qs(int cpu)
 {
         struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu);
-        rdp->passed_quiesc = 1;
         rdp->passed_quiesc_completed = rdp->completed;
+        barrier();
+        rdp->passed_quiesc = 1;
 }
 
 /*
- * We have entered the scheduler or are between softirqs in ksoftirqd.
- * If we are in an RCU read-side critical section, we need to reflect
- * that in the state of the rcu_node structure corresponding to this CPU.
- * Caller must disable hardirqs.
+ * We have entered the scheduler, and the current task might soon be
+ * context-switched away from.  If this task is in an RCU read-side
+ * critical section, we will no longer be able to rely on the CPU to
+ * record that fact, so we enqueue the task on the appropriate entry
+ * of the blocked_tasks[] array.  The task will dequeue itself when
+ * it exits the outermost enclosing RCU read-side critical section.
+ * Therefore, the current grace period cannot be permitted to complete
+ * until the blocked_tasks[] entry indexed by the low-order bit of
+ * rnp->gpnum empties.
+ *
+ * Caller must disable preemption.
  */
-static void rcu_preempt_qs(int cpu)
+static void rcu_preempt_note_context_switch(int cpu)
 {
         struct task_struct *t = current;
+        unsigned long flags;
         int phase;
         struct rcu_data *rdp;
         struct rcu_node *rnp;
@@ -90,7 +99,7 @@ static void rcu_preempt_qs(int cpu)
                 /* Possibly blocking in an RCU read-side critical section. */
                 rdp = rcu_preempt_state.rda[cpu];
                 rnp = rdp->mynode;
-                spin_lock(&rnp->lock);
+                spin_lock_irqsave(&rnp->lock, flags);
                 t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;
                 t->rcu_blocked_node = rnp;
 
@@ -103,11 +112,15 @@ static void rcu_preempt_qs(int cpu)
                  * state for the current grace period), then as long
                  * as that task remains queued, the current grace period
                  * cannot end.
+                 *
+                 * But first, note that the current CPU must still be
+                 * on line!
                  */
-                phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1);
+                WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0);
+                WARN_ON_ONCE(!list_empty(&t->rcu_node_entry));
+                phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1;
                 list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]);
-                smp_mb();  /* Ensure later ctxt swtch seen after above. */
-                spin_unlock(&rnp->lock);
+                spin_unlock_irqrestore(&rnp->lock, flags);
         }
 
         /*
@@ -119,9 +132,10 @@ static void rcu_preempt_qs(int cpu)
          * grace period, then the fact that the task has been enqueued
          * means that we continue to block the current grace period.
          */
-        rcu_preempt_qs_record(cpu);
-        t->rcu_read_unlock_special &= ~(RCU_READ_UNLOCK_NEED_QS |
-                                        RCU_READ_UNLOCK_GOT_QS);
+        rcu_preempt_qs(cpu);
+        local_irq_save(flags);
+        t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
+        local_irq_restore(flags);
 }
 
 /*
@@ -136,6 +150,16 @@ void __rcu_read_lock(void)
 }
 EXPORT_SYMBOL_GPL(__rcu_read_lock);
 
+/*
+ * Check for preempted RCU readers blocking the current grace period
+ * for the specified rcu_node structure.  If the caller needs a reliable
+ * answer, it must hold the rcu_node's ->lock.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
+{
+        return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+}
+
 static void rcu_read_unlock_special(struct task_struct *t)
 {
         int empty;
@@ -157,7 +181,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
         special = t->rcu_read_unlock_special;
         if (special & RCU_READ_UNLOCK_NEED_QS) {
                 t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
-                t->rcu_read_unlock_special |= RCU_READ_UNLOCK_GOT_QS;
+                rcu_preempt_qs(smp_processor_id());
         }
 
         /* Hardware IRQ handlers cannot block. */
@@ -177,12 +201,12 @@ static void rcu_read_unlock_special(struct task_struct *t)
                  */
                 for (;;) {
                         rnp = t->rcu_blocked_node;
-                        spin_lock(&rnp->lock);
+                        spin_lock(&rnp->lock);  /* irqs already disabled. */
                         if (rnp == t->rcu_blocked_node)
                                 break;
-                        spin_unlock(&rnp->lock);
+                        spin_unlock(&rnp->lock);  /* irqs remain disabled. */
                 }
-                empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+                empty = !rcu_preempted_readers(rnp);
                 list_del_init(&t->rcu_node_entry);
                 t->rcu_blocked_node = NULL;
 
@@ -193,10 +217,9 @@ static void rcu_read_unlock_special(struct task_struct *t)
                  * drop rnp->lock and restore irq.
                  */
                 if (!empty && rnp->qsmask == 0 &&
-                    list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) {
-                        t->rcu_read_unlock_special &=
-                                ~(RCU_READ_UNLOCK_NEED_QS |
-                                  RCU_READ_UNLOCK_GOT_QS);
+                    !rcu_preempted_readers(rnp)) {
+                        struct rcu_node *rnp_p;
+
                         if (rnp->parent == NULL) {
                                 /* Only one rcu_node in the tree. */
                                 cpu_quiet_msk_finish(&rcu_preempt_state, flags);
@@ -205,9 +228,10 @@ static void rcu_read_unlock_special(struct task_struct *t)
                         /* Report up the rest of the hierarchy. */
                         mask = rnp->grpmask;
                         spin_unlock_irqrestore(&rnp->lock, flags);
-                        rnp = rnp->parent;
-                        spin_lock_irqsave(&rnp->lock, flags);
-                        cpu_quiet_msk(mask, &rcu_preempt_state, rnp, flags);
+                        rnp_p = rnp->parent;
+                        spin_lock_irqsave(&rnp_p->lock, flags);
+                        WARN_ON_ONCE(rnp->qsmask);
+                        cpu_quiet_msk(mask, &rcu_preempt_state, rnp_p, flags);
                         return;
                 }
                 spin_unlock(&rnp->lock);
@@ -243,12 +267,12 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 {
         unsigned long flags;
         struct list_head *lp;
-        int phase = rnp->gpnum & 0x1;
+        int phase;
         struct task_struct *t;
 
-        if (!list_empty(&rnp->blocked_tasks[phase])) {
+        if (rcu_preempted_readers(rnp)) {
                 spin_lock_irqsave(&rnp->lock, flags);
-                phase = rnp->gpnum & 0x1; /* re-read under lock. */
+                phase = rnp->gpnum & 0x1;
                 lp = &rnp->blocked_tasks[phase];
                 list_for_each_entry(t, lp, rcu_node_entry)
                         printk(" P%d", t->pid);
@@ -259,13 +283,16 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 
 /*
- * Check for preempted RCU readers for the specified rcu_node structure.
- * If the caller needs a reliable answer, it must hold the rcu_node's
- * >lock.
+ * Check that the list of blocked tasks for the newly completed grace
+ * period is in fact empty.  It is a serious bug to complete a grace
+ * period that still has RCU readers blocked!  This function must be
+ * invoked -before- updating this rnp's ->gpnum, and the rnp's ->lock
+ * must be held by the caller.
  */
-static int rcu_preempted_readers(struct rcu_node *rnp)
+static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
 {
-        return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+        WARN_ON_ONCE(rcu_preempted_readers(rnp));
+        WARN_ON_ONCE(rnp->qsmask);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -280,7 +307,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
  * The caller must hold rnp->lock with irqs disabled.
  */
 static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-                                      struct rcu_node *rnp)
+                                      struct rcu_node *rnp,
+                                      struct rcu_data *rdp)
 {
         int i;
         struct list_head *lp;
@@ -292,6 +320,9 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
                 WARN_ONCE(1, "Last CPU thought to be offlined?");
                 return;  /* Shouldn't happen: at least one CPU online. */
         }
+        WARN_ON_ONCE(rnp != rdp->mynode &&
+                     (!list_empty(&rnp->blocked_tasks[0]) ||
+                      !list_empty(&rnp->blocked_tasks[1])));
 
         /*
          * Move tasks up to root rcu_node.  Rely on the fact that the
@@ -335,20 +366,12 @@ static void rcu_preempt_check_callbacks(int cpu)
         struct task_struct *t = current;
 
         if (t->rcu_read_lock_nesting == 0) {
-                t->rcu_read_unlock_special &=
-                        ~(RCU_READ_UNLOCK_NEED_QS | RCU_READ_UNLOCK_GOT_QS);
-                rcu_preempt_qs_record(cpu);
+                t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
+                rcu_preempt_qs(cpu);
                 return;
         }
-        if (per_cpu(rcu_preempt_data, cpu).qs_pending) {
-                if (t->rcu_read_unlock_special & RCU_READ_UNLOCK_GOT_QS) {
-                        rcu_preempt_qs_record(cpu);
-                        t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_GOT_QS;
-                } else if (!(t->rcu_read_unlock_special &
-                             RCU_READ_UNLOCK_NEED_QS)) {
-                        t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
-                }
-        }
+        if (per_cpu(rcu_preempt_data, cpu).qs_pending)
+                t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
 }
 
 /*
@@ -387,6 +410,15 @@ static int rcu_preempt_needs_cpu(int cpu)
         return !!per_cpu(rcu_preempt_data, cpu).nxtlist;
 }
 
+/**
+ * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
+ */
+void rcu_barrier(void)
+{
+        _rcu_barrier(&rcu_preempt_state, call_rcu);
+}
+EXPORT_SYMBOL_GPL(rcu_barrier);
+
 /*
  * Initialize preemptable RCU's per-CPU data.
  */
@@ -396,6 +428,22 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
 }
 
 /*
+ * Move preemptable RCU's callbacks to ->orphan_cbs_list.
+ */
+static void rcu_preempt_send_cbs_to_orphanage(void)
+{
+        rcu_send_cbs_to_orphanage(&rcu_preempt_state);
+}
+
+/*
+ * Initialize preemptable RCU's state structures.
+ */
+static void __init __rcu_init_preempt(void)
+{
+        RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
+}
+
+/*
  * Check for a task exiting while in a preemptable-RCU read-side
  * critical section, clean up if so.  No need to issue warnings,
  * as debug_check_no_locks_held() already does this if lockdep
@@ -434,8 +482,17 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed);
  * Because preemptable RCU does not exist, we never have to check for
  * CPUs being in quiescent states.
  */
-static void rcu_preempt_qs(int cpu)
+static void rcu_preempt_note_context_switch(int cpu)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, there are never any preempted
+ * RCU readers.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
 {
+        return 0;
 }
 
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
@@ -451,12 +508,13 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 
 /*
- * Because preemptable RCU does not exist, there are never any preempted
- * RCU readers.
+ * Because there is no preemptable RCU, there can be no readers blocked,
+ * so there is no need to check for blocked tasks.  So check only for
+ * bogus qsmask values.
  */
-static int rcu_preempted_readers(struct rcu_node *rnp)
+static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
 {
-        return 0;
+        WARN_ON_ONCE(rnp->qsmask);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -466,7 +524,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
  * tasks that were blocked within RCU read-side critical sections.
  */
 static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-                                      struct rcu_node *rnp)
+                                      struct rcu_node *rnp,
+                                      struct rcu_data *rdp)
 {
 }
 
@@ -484,7 +543,7 @@ static void rcu_preempt_offline_cpu(int cpu)
  * Because preemptable RCU does not exist, it never has any callbacks
  * to check.
  */
-void rcu_preempt_check_callbacks(int cpu)
+static void rcu_preempt_check_callbacks(int cpu)
 {
 }
 
@@ -492,7 +551,7 @@ void rcu_preempt_check_callbacks(int cpu)
  * Because preemptable RCU does not exist, it never has any callbacks
  * to process.
  */
-void rcu_preempt_process_callbacks(void)
+static void rcu_preempt_process_callbacks(void)
 {
 }
 
@@ -522,6 +581,16 @@ static int rcu_preempt_needs_cpu(int cpu)
 }
 
 /*
+ * Because preemptable RCU does not exist, rcu_barrier() is just
+ * another name for rcu_barrier_sched().
+ */
+void rcu_barrier(void)
+{
+        rcu_barrier_sched();
+}
+EXPORT_SYMBOL_GPL(rcu_barrier);
+
+/*
  * Because preemptable RCU does not exist, there is no per-CPU
  * data to initialize.
  */
@@ -529,4 +598,18 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
 {
 }
 
+/*
+ * Because there is no preemptable RCU, there are no callbacks to move.
+ */
+static void rcu_preempt_send_cbs_to_orphanage(void)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, it need not be initialized.
+ */
+static void __init __rcu_init_preempt(void)
+{
+}
+
 #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 0ea1bff69727..4b31c779e62e 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -20,7 +20,7 @@
  * Papers:  http://www.rdrop.com/users/paulmck/RCU
  *
  * For detailed explanation of Read-Copy Update mechanism see -
- *              Documentation/RCU
+ *              Documentation/RCU
  *
  */
 #include <linux/types.h>
@@ -93,7 +93,7 @@ static int rcudata_open(struct inode *inode, struct file *file)
         return single_open(file, show_rcudata, NULL);
 }
 
-static struct file_operations rcudata_fops = {
+static const struct file_operations rcudata_fops = {
         .owner = THIS_MODULE,
         .open = rcudata_open,
         .read = seq_read,
@@ -145,7 +145,7 @@ static int rcudata_csv_open(struct inode *inode, struct file *file)
         return single_open(file, show_rcudata_csv, NULL);
 }
 
-static struct file_operations rcudata_csv_fops = {
+static const struct file_operations rcudata_csv_fops = {
         .owner = THIS_MODULE,
         .open = rcudata_csv_open,
         .read = seq_read,
@@ -159,13 +159,13 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
         struct rcu_node *rnp;
 
         seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
-                      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
+                      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld\n",
                    rsp->completed, rsp->gpnum, rsp->signaled,
                    (long)(rsp->jiffies_force_qs - jiffies),
                    (int)(jiffies & 0xffff),
                    rsp->n_force_qs, rsp->n_force_qs_ngp,
                    rsp->n_force_qs - rsp->n_force_qs_ngp,
-                   rsp->n_force_qs_lh);
+                   rsp->n_force_qs_lh, rsp->orphan_qlen);
         for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
                 if (rnp->level != level) {
                         seq_puts(m, "\n");
@@ -196,7 +196,7 @@ static int rcuhier_open(struct inode *inode, struct file *file)
         return single_open(file, show_rcuhier, NULL);
 }
 
-static struct file_operations rcuhier_fops = {
+static const struct file_operations rcuhier_fops = {
         .owner = THIS_MODULE,
         .open = rcuhier_open,
         .read = seq_read,
@@ -222,7 +222,7 @@ static int rcugp_open(struct inode *inode, struct file *file)
         return single_open(file, show_rcugp, NULL);
 }
 
-static struct file_operations rcugp_fops = {
+static const struct file_operations rcugp_fops = {
         .owner = THIS_MODULE,
         .open = rcugp_open,
         .read = seq_read,
@@ -276,7 +276,7 @@ static int rcu_pending_open(struct inode *inode, struct file *file)
         return single_open(file, show_rcu_pending, NULL);
 }
 
-static struct file_operations rcu_pending_fops = {
+static const struct file_operations rcu_pending_fops = {
         .owner = THIS_MODULE,
         .open = rcu_pending_open,
         .read = seq_read,
diff --git a/kernel/relay.c b/kernel/relay.c
index bc188549788f..760c26209a3c 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -60,7 +60,7 @@ static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 /*
  * vm_ops for relay file mappings.
  */
-static struct vm_operations_struct relay_file_mmap_ops = {
+static const struct vm_operations_struct relay_file_mmap_ops = {
         .fault = relay_buf_fault,
         .close = relay_file_mmap_close,
 };
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index e1338f074314..bcdabf37c40b 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -19,6 +19,7 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent)
 {
         spin_lock_init(&counter->lock);
         counter->limit = RESOURCE_MAX;
+        counter->soft_limit = RESOURCE_MAX;
         counter->parent = parent;
 }
 
@@ -101,6 +102,8 @@ res_counter_member(struct res_counter *counter, int member)
                 return &counter->limit;
         case RES_FAILCNT:
                 return &counter->failcnt;
+        case RES_SOFT_LIMIT:
+                return &counter->soft_limit;
         };
 
         BUG();
diff --git a/kernel/resource.c b/kernel/resource.c
index 78b087221c15..fb11a58b9594 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -223,13 +223,13 @@ int release_resource(struct resource *old)
 
 EXPORT_SYMBOL(release_resource);
 
-#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
+#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 /*
  * Finds the lowest memory reosurce exists within [res->start.res->end)
- * the caller must specify res->start, res->end, res->flags.
+ * the caller must specify res->start, res->end, res->flags and "name".
  * If found, returns 0, res is overwritten, if not found, returns -1.
  */
-static int find_next_system_ram(struct resource *res)
+static int find_next_system_ram(struct resource *res, char *name)
 {
         resource_size_t start, end;
         struct resource *p;
@@ -245,6 +245,8 @@ static int find_next_system_ram(struct resource *res)
                 /* system ram is just marked as IORESOURCE_MEM */
                 if (p->flags != res->flags)
                         continue;
+                if (name && strcmp(p->name, name))
+                        continue;
                 if (p->start > end) {
                         p = NULL;
                         break;
@@ -262,19 +264,26 @@ static int find_next_system_ram(struct resource *res)
                 res->end = p->end;
         return 0;
 }
-int
-walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
-                        int (*func)(unsigned long, unsigned long, void *))
+
+/*
+ * This function calls callback against all memory range of "System RAM"
+ * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
+ * Now, this function is only for "System RAM".
+ */
+int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
+                void *arg, int (*func)(unsigned long, unsigned long, void *))
 {
         struct resource res;
         unsigned long pfn, len;
         u64 orig_end;
         int ret = -1;
+
         res.start = (u64) start_pfn << PAGE_SHIFT;
         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
         res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
         orig_end = res.end;
-        while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
+        while ((res.start < res.end) &&
+                (find_next_system_ram(&res, "System RAM") >= 0)) {
                 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
                 len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
                 ret = (*func)(pfn, len, arg);
diff --git a/kernel/sched.c b/kernel/sched.c
index a56446d7fda2..e5205811c19e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -39,7 +39,7 @@
 #include <linux/completion.h>
 #include <linux/kernel_stat.h>
 #include <linux/debug_locks.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <linux/security.h>
 #include <linux/notifier.h>
 #include <linux/profile.h>
@@ -676,6 +676,7 @@ inline void update_rq_clock(struct rq *rq)
 
 /**
  * runqueue_is_locked
+ * @cpu: the processor in question.
  *
  * Returns true if the current cpu runqueue is locked.
  * This interface allows printk to be called with the runqueue lock
@@ -780,7 +781,7 @@ static int sched_feat_open(struct inode *inode, struct file *filp)
         return single_open(filp, sched_feat_show, NULL);
 }
 
-static struct file_operations sched_feat_fops = {
+static const struct file_operations sched_feat_fops = {
         .open           = sched_feat_open,
         .write          = sched_feat_write,
         .read           = seq_read,
@@ -2053,7 +2054,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
                 if (task_hot(p, old_rq->clock, NULL))
                         schedstat_inc(p, se.nr_forced2_migrations);
 #endif
-                perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS,
+                perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
                                      1, 1, NULL, 0);
         }
         p->se.vruntime -= old_cfsrq->min_vruntime -
@@ -2311,7 +2312,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 {
         int cpu, orig_cpu, this_cpu, success = 0;
         unsigned long flags;
-        struct rq *rq;
+        struct rq *rq, *orig_rq;
 
         if (!sched_feat(SYNC_WAKEUPS))
                 wake_flags &= ~WF_SYNC;
@@ -2319,7 +2320,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
         this_cpu = get_cpu();
 
         smp_wmb();
-        rq = task_rq_lock(p, &flags);
+        rq = orig_rq = task_rq_lock(p, &flags);
         update_rq_clock(rq);
         if (!(p->state & state))
                 goto out;
@@ -2350,6 +2351,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
                 set_task_cpu(p, cpu);
 
         rq = task_rq_lock(p, &flags);
+
+        if (rq != orig_rq)
+                update_rq_clock(rq);
+
         WARN_ON(p->state != TASK_WAKING);
         cpu = task_cpu(p);
 
@@ -2515,22 +2520,17 @@ void sched_fork(struct task_struct *p, int clone_flags)
         __sched_fork(p);
 
         /*
-         * Make sure we do not leak PI boosting priority to the child.
-         */
-        p->prio = current->normal_prio;
-
-        /*
          * Revert to default priority/policy on fork if requested.
          */
         if (unlikely(p->sched_reset_on_fork)) {
-                if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+                if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) {
                         p->policy = SCHED_NORMAL;
-
-                if (p->normal_prio < DEFAULT_PRIO)
-                        p->prio = DEFAULT_PRIO;
+                        p->normal_prio = p->static_prio;
+                }
 
                 if (PRIO_TO_NICE(p->static_prio) < 0) {
                         p->static_prio = NICE_TO_PRIO(0);
+                        p->normal_prio = p->static_prio;
                         set_load_weight(p);
                 }
 
@@ -2541,6 +2541,11 @@ void sched_fork(struct task_struct *p, int clone_flags)
                 p->sched_reset_on_fork = 0;
         }
 
+        /*
+         * Make sure we do not leak PI boosting priority to the child.
+         */
+        p->prio = current->normal_prio;
+
         if (!rt_prio(p->prio))
                 p->sched_class = &fair_sched_class;
 
@@ -2581,8 +2586,6 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
         BUG_ON(p->state != TASK_RUNNING);
         update_rq_clock(rq);
 
-        p->prio = effective_prio(p);
-
         if (!p->sched_class->task_new || !current->se.on_rq) {
                 activate_task(rq, p, 0);
         } else {
@@ -2718,7 +2721,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
          */
         prev_state = prev->state;
         finish_arch_switch(prev);
-        perf_counter_task_sched_in(current, cpu_of(rq));
+        perf_event_task_sched_in(current, cpu_of(rq));
         finish_lock_switch(rq, prev);
 
         fire_sched_in_preempt_notifiers(current);
@@ -2904,6 +2907,19 @@ unsigned long nr_iowait(void)
         return sum;
 }
 
+unsigned long nr_iowait_cpu(void)
+{
+        struct rq *this = this_rq();
+        return atomic_read(&this->nr_iowait);
+}
+
+unsigned long this_cpu_load(void)
+{
+        struct rq *this = this_rq();
+        return this->cpu_load[0];
+}
+
+
 /* Variables and functions for calc_load */
 static atomic_long_t calc_load_tasks;
 static unsigned long calc_load_update;
@@ -3645,6 +3661,7 @@ static void update_group_power(struct sched_domain *sd, int cpu)
 
 /**
  * update_sg_lb_stats - Update sched_group's statistics for load balancing.
+ * @sd: The sched_domain whose statistics are to be updated.
  * @group: sched_group whose statistics are to be updated.
  * @this_cpu: Cpu for which load balance is currently performed.
  * @idle: Idle status of this_cpu
@@ -5079,17 +5096,16 @@ void account_idle_time(cputime_t cputime)
  */
 void account_process_tick(struct task_struct *p, int user_tick)
 {
-        cputime_t one_jiffy = jiffies_to_cputime(1);
-        cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
+        cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
         struct rq *rq = this_rq();
 
         if (user_tick)
-                account_user_time(p, one_jiffy, one_jiffy_scaled);
+                account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
         else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
-                account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
+                account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
                                     one_jiffy_scaled);
         else
-                account_idle_time(one_jiffy);
+                account_idle_time(cputime_one_jiffy);
 }
 
 /*
@@ -5193,7 +5209,7 @@ void scheduler_tick(void)
         curr->sched_class->task_tick(rq, curr, 0);
         spin_unlock(&rq->lock);
 
-        perf_counter_task_tick(curr, cpu);
+        perf_event_task_tick(curr, cpu);
 
 #ifdef CONFIG_SMP
         rq->idle_at_tick = idle_cpu(cpu);
@@ -5409,7 +5425,7 @@ need_resched_nonpreemptible:
 
         if (likely(prev != next)) {
                 sched_info_switch(prev, next);
-                perf_counter_task_sched_out(prev, next, cpu);
+                perf_event_task_sched_out(prev, next, cpu);
 
                 rq->nr_switches++;
                 rq->curr = next;
@@ -6708,9 +6724,6 @@ EXPORT_SYMBOL(yield);
 /*
  * This task is about to go to sleep on IO. Increment rq->nr_iowait so
  * that process accounting knows that this is a task in IO wait state.
- *
- * But don't do that if it is a deliberate, throttling IO wait (this task
- * has set its backing_dev_info: the queue against which it should throttle)
  */
 void __sched io_schedule(void)
 {
@@ -7671,7 +7684,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 /*
  * Register at high priority so that task migration (migrate_all_tasks)
  * happens before everything else.  This has to be lower priority than
- * the notifier in the perf_counter subsystem, though.
+ * the notifier in the perf_event subsystem, though.
  */
 static struct notifier_block __cpuinitdata migration_notifier = {
         .notifier_call = migration_call,
@@ -9524,7 +9537,7 @@ void __init sched_init(void)
         alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
 #endif /* SMP */
 
-        perf_counter_init();
+        perf_event_init();
 
         scheduler_running = 1;
 }
@@ -10296,7 +10309,7 @@ static int sched_rt_global_constraints(void)
 #endif /* CONFIG_RT_GROUP_SCHED */
 
 int sched_rt_handler(struct ctl_table *table, int write,
-                struct file *filp, void __user *buffer, size_t *lenp,
+                void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
         int ret;
@@ -10307,7 +10320,7 @@ int sched_rt_handler(struct ctl_table *table, int write,
         old_period = sysctl_sched_rt_period;
         old_runtime = sysctl_sched_rt_runtime;
 
-        ret = proc_dointvec(table, write, filp, buffer, lenp, ppos);
+        ret = proc_dointvec(table, write, buffer, lenp, ppos);
 
         if (!ret && write) {
                 ret = sched_rt_global_constraints();
@@ -10361,8 +10374,7 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
 }
 
 static int
-cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                      struct task_struct *tsk)
+cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
         if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
@@ -10372,15 +10384,45 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
         if (tsk->sched_class != &fair_sched_class)
                 return -EINVAL;
 #endif
+        return 0;
+}
 
+static int
+cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+                      struct task_struct *tsk, bool threadgroup)
+{
+        int retval = cpu_cgroup_can_attach_task(cgrp, tsk);
+        if (retval)
+                return retval;
+        if (threadgroup) {
+                struct task_struct *c;
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+                        retval = cpu_cgroup_can_attach_task(cgrp, c);
+                        if (retval) {
+                                rcu_read_unlock();
+                                return retval;
+                        }
+                }
+                rcu_read_unlock();
+        }
         return 0;
 }
 
 static void
 cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                        struct cgroup *old_cont, struct task_struct *tsk)
+                  struct cgroup *old_cont, struct task_struct *tsk,
+                  bool threadgroup)
 {
         sched_move_task(tsk);
+        if (threadgroup) {
+                struct task_struct *c;
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+                        sched_move_task(c);
+                }
+                rcu_read_unlock();
+        }
 }
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index e1d16c9a7680..479ce5682d7c 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -48,13 +48,6 @@ static __read_mostly int sched_clock_running;
 __read_mostly int sched_clock_stable;
 
 struct sched_clock_data {
-        /*
-         * Raw spinlock - this is a special case: this might be called
-         * from within instrumentation code so we dont want to do any
-         * instrumentation ourselves.
-         */
-        raw_spinlock_t          lock;
-
         u64                     tick_raw;
         u64                     tick_gtod;
         u64                     clock;
@@ -80,7 +73,6 @@ void sched_clock_init(void)
         for_each_possible_cpu(cpu) {
                 struct sched_clock_data *scd = cpu_sdc(cpu);
 
-                scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
                 scd->tick_raw = 0;
                 scd->tick_gtod = ktime_now;
                 scd->clock = ktime_now;
@@ -109,14 +101,19 @@ static inline u64 wrap_max(u64 x, u64 y)
  *  - filter out backward motion
  *  - use the GTOD tick value to create a window to filter crazy TSC values
  */
-static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
+static u64 sched_clock_local(struct sched_clock_data *scd)
 {
-        s64 delta = now - scd->tick_raw;
-        u64 clock, min_clock, max_clock;
+        u64 now, clock, old_clock, min_clock, max_clock;
+        s64 delta;
 
+again:
+        now = sched_clock();
+        delta = now - scd->tick_raw;
         if (unlikely(delta < 0))
                 delta = 0;
 
+        old_clock = scd->clock;
+
         /*
          * scd->clock = clamp(scd->tick_gtod + delta,
          *                    max(scd->tick_gtod, scd->clock),
@@ -124,84 +121,73 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
          */
 
         clock = scd->tick_gtod + delta;
-        min_clock = wrap_max(scd->tick_gtod, scd->clock);
-        max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
+        min_clock = wrap_max(scd->tick_gtod, old_clock);
+        max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC);
 
         clock = wrap_max(clock, min_clock);
         clock = wrap_min(clock, max_clock);
 
-        scd->clock = clock;
+        if (cmpxchg64(&scd->clock, old_clock, clock) != old_clock)
+                goto again;
 
-        return scd->clock;
+        return clock;
 }
 
-static void lock_double_clock(struct sched_clock_data *data1,
-                                struct sched_clock_data *data2)
+static u64 sched_clock_remote(struct sched_clock_data *scd)
 {
-        if (data1 < data2) {
-                __raw_spin_lock(&data1->lock);
-                __raw_spin_lock(&data2->lock);
+        struct sched_clock_data *my_scd = this_scd();
+        u64 this_clock, remote_clock;
+        u64 *ptr, old_val, val;
+
+        sched_clock_local(my_scd);
+again:
+        this_clock = my_scd->clock;
+        remote_clock = scd->clock;
+
+        /*
+         * Use the opportunity that we have both locks
+         * taken to couple the two clocks: we take the
+         * larger time as the latest time for both
+         * runqueues. (this creates monotonic movement)
+         */
+        if (likely((s64)(remote_clock - this_clock) < 0)) {
+                ptr = &scd->clock;
+                old_val = remote_clock;
+                val = this_clock;
         } else {
-                __raw_spin_lock(&data2->lock);
-                __raw_spin_lock(&data1->lock);
+                /*
+                 * Should be rare, but possible:
+                 */
+                ptr = &my_scd->clock;
+                old_val = this_clock;
+                val = remote_clock;
         }
+
+        if (cmpxchg64(ptr, old_val, val) != old_val)
+                goto again;
+
+        return val;
 }
 
 u64 sched_clock_cpu(int cpu)
 {
-        u64 now, clock, this_clock, remote_clock;
         struct sched_clock_data *scd;
+        u64 clock;
+
+        WARN_ON_ONCE(!irqs_disabled());
 
         if (sched_clock_stable)
                 return sched_clock();
 
-        scd = cpu_sdc(cpu);
-
-        /*
-         * Normally this is not called in NMI context - but if it is,
-         * trying to do any locking here is totally lethal.
-         */
-        if (unlikely(in_nmi()))
-                return scd->clock;
-
         if (unlikely(!sched_clock_running))
                 return 0ull;
 
-        WARN_ON_ONCE(!irqs_disabled());
-        now = sched_clock();
-
-        if (cpu != raw_smp_processor_id()) {
-                struct sched_clock_data *my_scd = this_scd();
-
-                lock_double_clock(scd, my_scd);
-
-                this_clock = __update_sched_clock(my_scd, now);
-                remote_clock = scd->clock;
-
-                /*
-                 * Use the opportunity that we have both locks
-                 * taken to couple the two clocks: we take the
-                 * larger time as the latest time for both
-                 * runqueues. (this creates monotonic movement)
-                 */
-                if (likely((s64)(remote_clock - this_clock) < 0)) {
-                        clock = this_clock;
-                        scd->clock = clock;
-                } else {
-                        /*
-                         * Should be rare, but possible:
-                         */
-                        clock = remote_clock;
-                        my_scd->clock = remote_clock;
-                }
-
-                __raw_spin_unlock(&my_scd->lock);
-        } else {
-                __raw_spin_lock(&scd->lock);
-                clock = __update_sched_clock(scd, now);
-        }
+        scd = cpu_sdc(cpu);
 
-        __raw_spin_unlock(&scd->lock);
+        if (cpu != smp_processor_id())
+                clock = sched_clock_remote(scd);
+        else
+                clock = sched_clock_local(scd);
 
         return clock;
 }
@@ -223,11 +209,9 @@ void sched_clock_tick(void)
         now_gtod = ktime_to_ns(ktime_get());
         now = sched_clock();
 
-        __raw_spin_lock(&scd->lock);
         scd->tick_raw = now;
         scd->tick_gtod = now_gtod;
-        __update_sched_clock(scd, now);
-        __raw_spin_unlock(&scd->lock);
+        sched_clock_local(scd);
 }
 
 /*
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index cd73738f0d5f..4e777b47eeda 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -384,10 +384,10 @@ static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 
 #ifdef CONFIG_SCHED_DEBUG
 int sched_nr_latency_handler(struct ctl_table *table, int write,
-                struct file *filp, void __user *buffer, size_t *lenp,
+                void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
-        int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+        int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 
         if (ret || !write)
                 return ret;
@@ -513,6 +513,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
         if (entity_is_task(curr)) {
                 struct task_struct *curtask = task_of(curr);
 
+                trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
                 cpuacct_charge(curtask, delta_exec);
                 account_group_exec_runtime(curtask, delta_exec);
         }
diff --git a/kernel/signal.c b/kernel/signal.c
index 64c5deeaca5d..6705320784fd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -705,7 +705,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
 
                 if (why) {
                         /*
-                         * The first thread which returns from finish_stop()
+                         * The first thread which returns from do_signal_stop()
                          * will take ->siglock, notice SIGNAL_CLD_MASK, and
                          * notify its parent. See get_signal_to_deliver().
                          */
@@ -971,6 +971,20 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
         return send_signal(sig, info, t, 0);
 }
 
+int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
+                        bool group)
+{
+        unsigned long flags;
+        int ret = -ESRCH;
+
+        if (lock_task_sighand(p, &flags)) {
+                ret = send_signal(sig, info, p, group);
+                unlock_task_sighand(p, &flags);
+        }
+
+        return ret;
+}
+
 /*
  * Force a signal that the process can't ignore: if necessary
  * we unblock the signal and change any SIG_IGN to SIG_DFL.
@@ -1036,12 +1050,6 @@ void zap_other_threads(struct task_struct *p)
         }
 }
 
-int __fatal_signal_pending(struct task_struct *tsk)
-{
-        return sigismember(&tsk->pending.signal, SIGKILL);
-}
-EXPORT_SYMBOL(__fatal_signal_pending);
-
 struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
 {
         struct sighand_struct *sighand;
@@ -1068,18 +1076,10 @@ struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long
  */
 int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 {
-        unsigned long flags;
-        int ret;
+        int ret = check_kill_permission(sig, info, p);
 
-        ret = check_kill_permission(sig, info, p);
-
-        if (!ret && sig) {
-                ret = -ESRCH;
-                if (lock_task_sighand(p, &flags)) {
-                        ret = __group_send_sig_info(sig, info, p);
-                        unlock_task_sighand(p, &flags);
-                }
-        }
+        if (!ret && sig)
+                ret = do_send_sig_info(sig, info, p, true);
 
         return ret;
 }
@@ -1224,15 +1224,9 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
  * These are for backward compatibility with the rest of the kernel source.
  */
 
-/*
- * The caller must ensure the task can't exit.
- */
 int
 send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 {
-        int ret;
-        unsigned long flags;
-
         /*
          * Make sure legacy kernel users don't send in bad values
          * (normal paths check this in check_kill_permission).
@@ -1240,10 +1234,7 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
         if (!valid_signal(sig))
                 return -EINVAL;
 
-        spin_lock_irqsave(&p->sighand->siglock, flags);
-        ret = specific_send_sig_info(sig, info, p);
-        spin_unlock_irqrestore(&p->sighand->siglock, flags);
-        return ret;
+        return do_send_sig_info(sig, info, p, false);
 }
 
 #define __si_special(priv) \
@@ -1383,15 +1374,6 @@ ret:
 }
 
 /*
- * Wake up any threads in the parent blocked in wait* syscalls.
- */
-static inline void __wake_up_parent(struct task_struct *p,
-                                    struct task_struct *parent)
-{
-        wake_up_interruptible_sync(&parent->signal->wait_chldexit);
-}
-
-/*
  * Let a parent know about the death of a child.
  * For a stopped/continued status change, use do_notify_parent_cldstop instead.
  *
@@ -1673,29 +1655,6 @@ void ptrace_notify(int exit_code)
         spin_unlock_irq(&current->sighand->siglock);
 }
 
-static void
-finish_stop(int stop_count)
-{
-        /*
-         * If there are no other threads in the group, or if there is
-         * a group stop in progress and we are the last to stop,
-         * report to the parent.  When ptraced, every thread reports itself.
-         */
-        if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) {
-                read_lock(&tasklist_lock);
-                do_notify_parent_cldstop(current, CLD_STOPPED);
-                read_unlock(&tasklist_lock);
-        }
-
-        do {
-                schedule();
-        } while (try_to_freeze());
-        /*
-         * Now we don't run again until continued.
-         */
-        current->exit_code = 0;
-}
-
 /*
  * This performs the stopping for SIGSTOP and other stop signals.
  * We have to stop all threads in the thread group.
@@ -1705,15 +1664,9 @@ finish_stop(int stop_count)
 static int do_signal_stop(int signr)
 {
         struct signal_struct *sig = current->signal;
-        int stop_count;
+        int notify;
 
-        if (sig->group_stop_count > 0) {
-                /*
-                 * There is a group stop in progress.  We don't need to
-                 * start another one.
-                 */
-                stop_count = --sig->group_stop_count;
-        } else {
+        if (!sig->group_stop_count) {
                 struct task_struct *t;
 
                 if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
@@ -1725,7 +1678,7 @@ static int do_signal_stop(int signr)
                  */
                 sig->group_exit_code = signr;
 
-                stop_count = 0;
+                sig->group_stop_count = 1;
                 for (t = next_thread(current); t != current; t = next_thread(t))
                         /*
                          * Setting state to TASK_STOPPED for a group
@@ -1734,19 +1687,44 @@ static int do_signal_stop(int signr)
                          */
                         if (!(t->flags & PF_EXITING) &&
                             !task_is_stopped_or_traced(t)) {
-                                stop_count++;
+                                sig->group_stop_count++;
                                 signal_wake_up(t, 0);
                         }
-                sig->group_stop_count = stop_count;
         }
+        /*
+         * If there are no other threads in the group, or if there is
+         * a group stop in progress and we are the last to stop, report
+         * to the parent.  When ptraced, every thread reports itself.
+         */
+        notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0;
+        notify = tracehook_notify_jctl(notify, CLD_STOPPED);
+        /*
+         * tracehook_notify_jctl() can drop and reacquire siglock, so
+         * we keep ->group_stop_count != 0 before the call. If SIGCONT
+         * or SIGKILL comes in between ->group_stop_count == 0.
+         */
+        if (sig->group_stop_count) {
+                if (!--sig->group_stop_count)
+                        sig->flags = SIGNAL_STOP_STOPPED;
+                current->exit_code = sig->group_exit_code;
+                __set_current_state(TASK_STOPPED);
+        }
+        spin_unlock_irq(&current->sighand->siglock);
 
-        if (stop_count == 0)
-                sig->flags = SIGNAL_STOP_STOPPED;
-        current->exit_code = sig->group_exit_code;
-        __set_current_state(TASK_STOPPED);
+        if (notify) {
+                read_lock(&tasklist_lock);
+                do_notify_parent_cldstop(current, notify);
+                read_unlock(&tasklist_lock);
+        }
+
+        /* Now we don't run again until woken by SIGCONT or SIGKILL */
+        do {
+                schedule();
+        } while (try_to_freeze());
+
+        tracehook_finish_jctl();
+        current->exit_code = 0;
 
-        spin_unlock_irq(&current->sighand->siglock);
-        finish_stop(stop_count);
         return 1;
 }
 
@@ -1815,14 +1793,15 @@ relock:
                 int why = (signal->flags & SIGNAL_STOP_CONTINUED)
                                 ? CLD_CONTINUED : CLD_STOPPED;
                 signal->flags &= ~SIGNAL_CLD_MASK;
-                spin_unlock_irq(&sighand->siglock);
 
-                if (unlikely(!tracehook_notify_jctl(1, why)))
-                        goto relock;
+                why = tracehook_notify_jctl(why, CLD_CONTINUED);
+                spin_unlock_irq(&sighand->siglock);
 
-                read_lock(&tasklist_lock);
-                do_notify_parent_cldstop(current->group_leader, why);
-                read_unlock(&tasklist_lock);
+                if (why) {
+                        read_lock(&tasklist_lock);
+                        do_notify_parent_cldstop(current->group_leader, why);
+                        read_unlock(&tasklist_lock);
+                }
                 goto relock;
         }
 
@@ -1987,14 +1966,14 @@ void exit_signals(struct task_struct *tsk)
         if (unlikely(tsk->signal->group_stop_count) &&
                         !--tsk->signal->group_stop_count) {
                 tsk->signal->flags = SIGNAL_STOP_STOPPED;
-                group_stop = 1;
+                group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED);
         }
 out:
         spin_unlock_irq(&tsk->sighand->siglock);
 
-        if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) {
+        if (unlikely(group_stop)) {
                 read_lock(&tasklist_lock);
-                do_notify_parent_cldstop(tsk, CLD_STOPPED);
+                do_notify_parent_cldstop(tsk, group_stop);
                 read_unlock(&tasklist_lock);
         }
 }
@@ -2290,7 +2269,6 @@ static int
 do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
 {
         struct task_struct *p;
-        unsigned long flags;
         int error = -ESRCH;
 
         rcu_read_lock();
@@ -2300,14 +2278,16 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
                 /*
                  * The null signal is a permissions and process existence
                  * probe.  No signal is actually delivered.
-                 *
-                 * If lock_task_sighand() fails we pretend the task dies
-                 * after receiving the signal. The window is tiny, and the
-                 * signal is private anyway.
                  */
-                if (!error && sig && lock_task_sighand(p, &flags)) {
-                        error = specific_send_sig_info(sig, info, p);
-                        unlock_task_sighand(p, &flags);
+                if (!error && sig) {
+                        error = do_send_sig_info(sig, info, p, false);
+                        /*
+                         * If lock_task_sighand() failed we pretend the task
+                         * dies after receiving the signal. The window is tiny,
+                         * and the signal is private anyway.
+                         */
+                        if (unlikely(error == -ESRCH))
+                                error = 0;
                 }
         }
         rcu_read_unlock();
diff --git a/kernel/slow-work.c b/kernel/slow-work.c
index 09d7519557d3..0d31135efbf4 100644
--- a/kernel/slow-work.c
+++ b/kernel/slow-work.c
@@ -26,10 +26,10 @@ static void slow_work_cull_timeout(unsigned long);
 static void slow_work_oom_timeout(unsigned long);
 
 #ifdef CONFIG_SYSCTL
-static int slow_work_min_threads_sysctl(struct ctl_table *, int, struct file *,
+static int slow_work_min_threads_sysctl(struct ctl_table *, int,
                                         void __user *, size_t *, loff_t *);
 
-static int slow_work_max_threads_sysctl(struct ctl_table *, int , struct file *,
+static int slow_work_max_threads_sysctl(struct ctl_table *, int ,
                                         void __user *, size_t *, loff_t *);
 #endif
 
@@ -493,10 +493,10 @@ static void slow_work_oom_timeout(unsigned long data)
  * Handle adjustment of the minimum number of threads
  */
 static int slow_work_min_threads_sysctl(struct ctl_table *table, int write,
-                                        struct file *filp, void __user *buffer,
+                                        void __user *buffer,
                                         size_t *lenp, loff_t *ppos)
 {
-        int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+        int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
         int n;
 
         if (ret == 0) {
@@ -521,10 +521,10 @@ static int slow_work_min_threads_sysctl(struct ctl_table *table, int write,
  * Handle adjustment of the maximum number of threads
  */
 static int slow_work_max_threads_sysctl(struct ctl_table *table, int write,
-                                        struct file *filp, void __user *buffer,
+                                        void __user *buffer,
                                         size_t *lenp, loff_t *ppos)
 {
-        int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+        int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
         int n;
 
         if (ret == 0) {
diff --git a/kernel/smp.c b/kernel/smp.c
index 8e218500ab14..c9d1c7835c2f 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -29,8 +29,7 @@ enum {
 
 struct call_function_data {
         struct call_single_data csd;
-        spinlock_t              lock;
-        unsigned int            refs;
+        atomic_t                refs;
         cpumask_var_t           cpumask;
 };
 
@@ -39,9 +38,7 @@ struct call_single_queue {
         spinlock_t              lock;
 };
 
-static DEFINE_PER_CPU(struct call_function_data, cfd_data) = {
-        .lock                   = __SPIN_LOCK_UNLOCKED(cfd_data.lock),
-};
+static DEFINE_PER_CPU(struct call_function_data, cfd_data);
 
 static int
 hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
@@ -196,25 +193,18 @@ void generic_smp_call_function_interrupt(void)
         list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
                 int refs;
 
-                spin_lock(&data->lock);
-                if (!cpumask_test_cpu(cpu, data->cpumask)) {
-                        spin_unlock(&data->lock);
+                if (!cpumask_test_and_clear_cpu(cpu, data->cpumask))
                         continue;
-                }
-                cpumask_clear_cpu(cpu, data->cpumask);
-                spin_unlock(&data->lock);
 
                 data->csd.func(data->csd.info);
 
-                spin_lock(&data->lock);
-                WARN_ON(data->refs == 0);
-                refs = --data->refs;
+                refs = atomic_dec_return(&data->refs);
+                WARN_ON(refs < 0);
                 if (!refs) {
                         spin_lock(&call_function.lock);
                         list_del_rcu(&data->csd.list);
                         spin_unlock(&call_function.lock);
                 }
-                spin_unlock(&data->lock);
 
                 if (refs)
                         continue;
@@ -357,13 +347,6 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
         generic_exec_single(cpu, data, wait);
 }
 
-/* Deprecated: shim for archs using old arch_send_call_function_ipi API. */
-
-#ifndef arch_send_call_function_ipi_mask
-# define arch_send_call_function_ipi_mask(maskp) \
-         arch_send_call_function_ipi(*(maskp))
-#endif
-
 /**
  * smp_call_function_many(): Run a function on a set of other CPUs.
  * @mask: The set of cpus to run on (only runs on online subset).
@@ -419,23 +402,20 @@ void smp_call_function_many(const struct cpumask *mask,
         data = &__get_cpu_var(cfd_data);
         csd_lock(&data->csd);
 
-        spin_lock_irqsave(&data->lock, flags);
         data->csd.func = func;
         data->csd.info = info;
         cpumask_and(data->cpumask, mask, cpu_online_mask);
         cpumask_clear_cpu(this_cpu, data->cpumask);
-        data->refs = cpumask_weight(data->cpumask);
+        atomic_set(&data->refs, cpumask_weight(data->cpumask));
 
-        spin_lock(&call_function.lock);
+        spin_lock_irqsave(&call_function.lock, flags);
         /*
          * Place entry at the _HEAD_ of the list, so that any cpu still
          * observing the entry in generic_smp_call_function_interrupt()
          * will not miss any other list entries:
          */
         list_add_rcu(&data->csd.list, &call_function.queue);
-        spin_unlock(&call_function.lock);
-
-        spin_unlock_irqrestore(&data->lock, flags);
+        spin_unlock_irqrestore(&call_function.lock, flags);
 
         /*
          * Make the list addition visible before sending the ipi.
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 88796c330838..81324d12eb35 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -90,11 +90,11 @@ void touch_all_softlockup_watchdogs(void)
 EXPORT_SYMBOL(touch_all_softlockup_watchdogs);
 
 int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
-                             struct file *filp, void __user *buffer,
+                             void __user *buffer,
                              size_t *lenp, loff_t *ppos)
 {
         touch_all_softlockup_watchdogs();
-        return proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+        return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 }
 
 /*
diff --git a/kernel/sys.c b/kernel/sys.c
index b3f1097c76fa..255475d163e0 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -14,7 +14,7 @@
 #include <linux/prctl.h>
 #include <linux/highuid.h>
 #include <linux/fs.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <linux/resource.h>
 #include <linux/kernel.h>
 #include <linux/kexec.h>
@@ -1338,6 +1338,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
         unsigned long flags;
         cputime_t utime, stime;
         struct task_cputime cputime;
+        unsigned long maxrss = 0;
 
         memset((char *) r, 0, sizeof *r);
         utime = stime = cputime_zero;
@@ -1346,6 +1347,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
                 utime = task_utime(current);
                 stime = task_stime(current);
                 accumulate_thread_rusage(p, r);
+                maxrss = p->signal->maxrss;
                 goto out;
         }
 
@@ -1363,6 +1365,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
                         r->ru_majflt = p->signal->cmaj_flt;
                         r->ru_inblock = p->signal->cinblock;
                         r->ru_oublock = p->signal->coublock;
+                        maxrss = p->signal->cmaxrss;
 
                         if (who == RUSAGE_CHILDREN)
                                 break;
@@ -1377,6 +1380,8 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
                         r->ru_majflt += p->signal->maj_flt;
                         r->ru_inblock += p->signal->inblock;
                         r->ru_oublock += p->signal->oublock;
+                        if (maxrss < p->signal->maxrss)
+                                maxrss = p->signal->maxrss;
                         t = p;
                         do {
                                 accumulate_thread_rusage(t, r);
@@ -1392,6 +1397,15 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 out:
         cputime_to_timeval(utime, &r->ru_utime);
         cputime_to_timeval(stime, &r->ru_stime);
+
+        if (who != RUSAGE_CHILDREN) {
+                struct mm_struct *mm = get_task_mm(p);
+                if (mm) {
+                        setmax_mm_hiwater_rss(&maxrss, mm);
+                        mmput(mm);
+                }
+        }
+        r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
 }
 
 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
@@ -1511,11 +1525,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
                 case PR_SET_TSC:
                         error = SET_TSC_CTL(arg2);
                         break;
-                case PR_TASK_PERF_COUNTERS_DISABLE:
-                        error = perf_counter_task_disable();
+                case PR_TASK_PERF_EVENTS_DISABLE:
+                        error = perf_event_task_disable();
                         break;
-                case PR_TASK_PERF_COUNTERS_ENABLE:
-                        error = perf_counter_task_enable();
+                case PR_TASK_PERF_EVENTS_ENABLE:
+                        error = perf_event_task_enable();
                         break;
                 case PR_GET_TIMERSLACK:
                         error = current->timer_slack_ns;
@@ -1528,6 +1542,28 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
                                 current->timer_slack_ns = arg2;
                         error = 0;
                         break;
+                case PR_MCE_KILL:
+                        if (arg4 | arg5)
+                                return -EINVAL;
+                        switch (arg2) {
+                        case 0:
+                                if (arg3 != 0)
+                                        return -EINVAL;
+                                current->flags &= ~PF_MCE_PROCESS;
+                                break;
+                        case 1:
+                                current->flags |= PF_MCE_PROCESS;
+                                if (arg3 != 0)
+                                        current->flags |= PF_MCE_EARLY;
+                                else
+                                        current->flags &= ~PF_MCE_EARLY;
+                                break;
+                        default:
+                                return -EINVAL;
+                        }
+                        error = 0;
+                        break;
+
                 default:
                         error = -EINVAL;
                         break;
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 68320f6b07b5..e06d0b8d1951 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -49,6 +49,7 @@ cond_syscall(sys_sendmsg);
 cond_syscall(compat_sys_sendmsg);
 cond_syscall(sys_recvmsg);
 cond_syscall(compat_sys_recvmsg);
+cond_syscall(compat_sys_recvfrom);
 cond_syscall(sys_socketcall);
 cond_syscall(sys_futex);
 cond_syscall(compat_sys_futex);
@@ -177,4 +178,4 @@ cond_syscall(sys_eventfd);
 cond_syscall(sys_eventfd2);
 
 /* performance counters: */
-cond_syscall(sys_perf_counter_open);
+cond_syscall(sys_perf_event_open);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1a631ba684a4..0d949c517412 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -26,7 +26,6 @@
 #include <linux/proc_fs.h>
 #include <linux/security.h>
 #include <linux/ctype.h>
-#include <linux/utsname.h>
 #include <linux/kmemcheck.h>
 #include <linux/smp_lock.h>
 #include <linux/fs.h>
@@ -50,7 +49,7 @@
 #include <linux/reboot.h>
 #include <linux/ftrace.h>
 #include <linux/slow-work.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -77,6 +76,7 @@ extern int max_threads;
 extern int core_uses_pid;
 extern int suid_dumpable;
 extern char core_pattern[];
+extern unsigned int core_pipe_limit;
 extern int pid_max;
 extern int min_free_kbytes;
 extern int pid_max_min, pid_max_max;
@@ -106,6 +106,9 @@ static int __maybe_unused one = 1;
 static int __maybe_unused two = 2;
 static unsigned long one_ul = 1;
 static int one_hundred = 100;
+#ifdef CONFIG_PRINTK
+static int ten_thousand = 10000;
+#endif
 
 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
@@ -160,9 +163,9 @@ extern int max_lock_depth;
 #endif
 
 #ifdef CONFIG_PROC_SYSCTL
-static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
+static int proc_do_cad_pid(struct ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos);
-static int proc_taint(struct ctl_table *table, int write, struct file *filp,
+static int proc_taint(struct ctl_table *table, int write,
                                void __user *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
@@ -421,6 +424,14 @@ static struct ctl_table kern_table[] = {
                 .proc_handler   = &proc_dostring,
                 .strategy       = &sysctl_string,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "core_pipe_limit",
+                .data           = &core_pipe_limit,
+                .maxlen         = sizeof(unsigned int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
 #ifdef CONFIG_PROC_SYSCTL
         {
                 .procname       = "tainted",
@@ -722,6 +733,17 @@ static struct ctl_table kern_table[] = {
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "printk_delay",
+                .data           = &printk_delay_msec,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &zero,
+                .extra2         = &ten_thousand,
+        },
 #endif
         {
                 .ctl_name       = KERN_NGROUPS_MAX,
@@ -964,28 +986,28 @@ static struct ctl_table kern_table[] = {
                 .child          = slow_work_sysctls,
         },
 #endif
-#ifdef CONFIG_PERF_COUNTERS
+#ifdef CONFIG_PERF_EVENTS
         {
                 .ctl_name       = CTL_UNNUMBERED,
-                .procname       = "perf_counter_paranoid",
-                .data           = &sysctl_perf_counter_paranoid,
-                .maxlen         = sizeof(sysctl_perf_counter_paranoid),
+                .procname       = "perf_event_paranoid",
+                .data           = &sysctl_perf_event_paranoid,
+                .maxlen         = sizeof(sysctl_perf_event_paranoid),
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
         },
         {
                 .ctl_name       = CTL_UNNUMBERED,
-                .procname       = "perf_counter_mlock_kb",
-                .data           = &sysctl_perf_counter_mlock,
-                .maxlen         = sizeof(sysctl_perf_counter_mlock),
+                .procname       = "perf_event_mlock_kb",
+                .data           = &sysctl_perf_event_mlock,
+                .maxlen         = sizeof(sysctl_perf_event_mlock),
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
         },
         {
                 .ctl_name       = CTL_UNNUMBERED,
-                .procname       = "perf_counter_max_sample_rate",
-                .data           = &sysctl_perf_counter_sample_rate,
-                .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
+                .procname       = "perf_event_max_sample_rate",
+                .data           = &sysctl_perf_event_sample_rate,
+                .maxlen         = sizeof(sysctl_perf_event_sample_rate),
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
         },
@@ -1376,6 +1398,31 @@ static struct ctl_table vm_table[] = {
                 .mode           = 0644,
                 .proc_handler   = &scan_unevictable_handler,
         },
+#ifdef CONFIG_MEMORY_FAILURE
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "memory_failure_early_kill",
+                .data           = &sysctl_memory_failure_early_kill,
+                .maxlen         = sizeof(sysctl_memory_failure_early_kill),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &zero,
+                .extra2         = &one,
+        },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "memory_failure_recovery",
+                .data           = &sysctl_memory_failure_recovery,
+                .maxlen         = sizeof(sysctl_memory_failure_recovery),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &zero,
+                .extra2         = &one,
+        },
+#endif
+
 /*
  * NOTE: do not add new entries to this table unless you have read
  * Documentation/sysctl/ctl_unnumbered.txt
@@ -2204,7 +2251,7 @@ void sysctl_head_put(struct ctl_table_header *head)
 #ifdef CONFIG_PROC_SYSCTL
 
 static int _proc_do_string(void* data, int maxlen, int write,
-                           struct file *filp, void __user *buffer,
+                           void __user *buffer,
                            size_t *lenp, loff_t *ppos)
 {
         size_t len;
@@ -2265,7 +2312,6 @@ static int _proc_do_string(void* data, int maxlen, int write,
  * proc_dostring - read a string sysctl
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2279,10 +2325,10 @@ static int _proc_do_string(void* data, int maxlen, int write,
  *
  * Returns 0 on success.
  */
-int proc_dostring(struct ctl_table *table, int write, struct file *filp,
+int proc_dostring(struct ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-        return _proc_do_string(table->data, table->maxlen, write, filp,
+        return _proc_do_string(table->data, table->maxlen, write,
                                buffer, lenp, ppos);
 }
 
@@ -2307,7 +2353,7 @@ static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
 }
 
 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
-                  int write, struct file *filp, void __user *buffer,
+                  int write, void __user *buffer,
                   size_t *lenp, loff_t *ppos,
                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
                               int write, void *data),
@@ -2414,13 +2460,13 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 #undef TMPBUFLEN
 }
 
-static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
+static int do_proc_dointvec(struct ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos,
                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
                               int write, void *data),
                   void *data)
 {
-        return __do_proc_dointvec(table->data, table, write, filp,
+        return __do_proc_dointvec(table->data, table, write,
                         buffer, lenp, ppos, conv, data);
 }
 
@@ -2428,7 +2474,6 @@ static int do_proc_dointvec(struct ctl_table *table, int write, struct file *fil
  * proc_dointvec - read a vector of integers
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2438,10 +2483,10 @@ static int do_proc_dointvec(struct ctl_table *table, int write, struct file *fil
  *
  * Returns 0 on success.
  */
-int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec(struct ctl_table *table, int write,
                      void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
                             NULL,NULL);
 }
 
@@ -2449,7 +2494,7 @@ int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
  * Taint values can only be increased
  * This means we can safely use a temporary.
  */
-static int proc_taint(struct ctl_table *table, int write, struct file *filp,
+static int proc_taint(struct ctl_table *table, int write,
                                void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         struct ctl_table t;
@@ -2461,7 +2506,7 @@ static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 
         t = *table;
         t.data = &tmptaint;
-        err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
+        err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
         if (err < 0)
                 return err;
 
@@ -2513,7 +2558,6 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
  * proc_dointvec_minmax - read a vector of integers with min/max values
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2526,19 +2570,18 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_minmax(struct ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         struct do_proc_dointvec_minmax_conv_param param = {
                 .min = (int *) table->extra1,
                 .max = (int *) table->extra2,
         };
-        return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
+        return do_proc_dointvec(table, write, buffer, lenp, ppos,
                                 do_proc_dointvec_minmax_conv, &param);
 }
 
 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
-                                     struct file *filp,
                                      void __user *buffer,
                                      size_t *lenp, loff_t *ppos,
                                      unsigned long convmul,
@@ -2643,21 +2686,19 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 }
 
 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
-                                     struct file *filp,
                                      void __user *buffer,
                                      size_t *lenp, loff_t *ppos,
                                      unsigned long convmul,
                                      unsigned long convdiv)
 {
         return __do_proc_doulongvec_minmax(table->data, table, write,
-                        filp, buffer, lenp, ppos, convmul, convdiv);
+                        buffer, lenp, ppos, convmul, convdiv);
 }
 
 /**
  * proc_doulongvec_minmax - read a vector of long integers with min/max values
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2670,17 +2711,16 @@ static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
-int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_doulongvec_minmax(struct ctl_table *table, int write,
                            void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
+    return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
 }
 
 /**
  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2695,11 +2735,10 @@ int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp
  * Returns 0 on success.
  */
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-                                      struct file *filp,
                                       void __user *buffer,
                                       size_t *lenp, loff_t *ppos)
 {
-    return do_proc_doulongvec_minmax(table, write, filp, buffer,
+    return do_proc_doulongvec_minmax(table, write, buffer,
                                      lenp, ppos, HZ, 1000l);
 }
 
@@ -2775,7 +2814,6 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
  * proc_dointvec_jiffies - read a vector of integers as seconds
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2787,10 +2825,10 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_jiffies(struct ctl_table *table, int write,
                           void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
                             do_proc_dointvec_jiffies_conv,NULL);
 }
 
@@ -2798,7 +2836,6 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: pointer to the file position
@@ -2810,10 +2847,10 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
                                  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
                             do_proc_dointvec_userhz_jiffies_conv,NULL);
 }
 
@@ -2821,7 +2858,6 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file
  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2834,14 +2870,14 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file
  *
  * Returns 0 on success.
  */
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
                              void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-        return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
+        return do_proc_dointvec(table, write, buffer, lenp, ppos,
                                 do_proc_dointvec_ms_jiffies_conv, NULL);
 }
 
-static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
+static int proc_do_cad_pid(struct ctl_table *table, int write,
                            void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         struct pid *new_pid;
@@ -2850,7 +2886,7 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp
 
         tmp = pid_vnr(cad_pid);
 
-        r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
+        r = __do_proc_dointvec(&tmp, table, write, buffer,
                                lenp, ppos, NULL, NULL);
         if (r || !write)
                 return r;
@@ -2865,50 +2901,49 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp
 
 #else /* CONFIG_PROC_FS */
 
-int proc_dostring(struct ctl_table *table, int write, struct file *filp,
+int proc_dostring(struct ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
-int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec(struct ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
-int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_minmax(struct ctl_table *table, int write,
                     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
-int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_jiffies(struct ctl_table *table, int write,
                     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
-int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
                     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
                              void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
-int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_doulongvec_minmax(struct ctl_table *table, int write,
                     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         return -ENOSYS;
 }
 
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-                                      struct file *filp,
                                       void __user *buffer,
                                       size_t *lenp, loff_t *ppos)
 {
diff --git a/kernel/time.c b/kernel/time.c
index 29511943871a..2e2e469a7fec 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -370,13 +370,20 @@ EXPORT_SYMBOL(mktime);
  *      0 <= tv_nsec < NSEC_PER_SEC
  * For negative values only the tv_sec field is negative !
  */
-void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec)
+void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec)
 {
         while (nsec >= NSEC_PER_SEC) {
+                /*
+                 * The following asm() prevents the compiler from
+                 * optimising this loop into a modulo operation. See
+                 * also __iter_div_u64_rem() in include/linux/time.h
+                 */
+                asm("" : "+rm"(nsec));
                 nsec -= NSEC_PER_SEC;
                 ++sec;
         }
         while (nsec < 0) {
+                asm("" : "+rm"(nsec));
                 nsec += NSEC_PER_SEC;
                 --sec;
         }
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 0b0a6366c9d4..ee266620b06c 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1,4 +1,4 @@
-obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o
+obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o timeconv.o
 
 obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD)         += clockevents.o
 obj-$(CONFIG_GENERIC_CLOCKEVENTS)               += tick-common.o
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 7466cb811251..5e18c6ab2c6a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -21,7 +21,6 @@
  *
  * TODO WishList:
  *   o Allow clocksource drivers to be unregistered
- *   o get rid of clocksource_jiffies extern
  */
 
 #include <linux/clocksource.h>
@@ -30,6 +29,7 @@
 #include <linux/module.h>
 #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
 #include <linux/tick.h>
+#include <linux/kthread.h>
 
 void timecounter_init(struct timecounter *tc,
                       const struct cyclecounter *cc,
@@ -107,50 +107,35 @@ u64 timecounter_cyc2time(struct timecounter *tc,
 }
 EXPORT_SYMBOL(timecounter_cyc2time);
 
-/* XXX - Would like a better way for initializing curr_clocksource */
-extern struct clocksource clocksource_jiffies;
-
 /*[Clocksource internal variables]---------
  * curr_clocksource:
- *      currently selected clocksource. Initialized to clocksource_jiffies.
- * next_clocksource:
- *      pending next selected clocksource.
+ *      currently selected clocksource.
  * clocksource_list:
  *      linked list with the registered clocksources
- * clocksource_lock:
- *      protects manipulations to curr_clocksource and next_clocksource
- *      and the clocksource_list
+ * clocksource_mutex:
+ *      protects manipulations to curr_clocksource and the clocksource_list
  * override_name:
  *      Name of the user-specified clocksource.
  */
-static struct clocksource *curr_clocksource = &clocksource_jiffies;
-static struct clocksource *next_clocksource;
-static struct clocksource *clocksource_override;
+static struct clocksource *curr_clocksource;
 static LIST_HEAD(clocksource_list);
-static DEFINE_SPINLOCK(clocksource_lock);
+static DEFINE_MUTEX(clocksource_mutex);
 static char override_name[32];
 static int finished_booting;
 
-/* clocksource_done_booting - Called near the end of core bootup
- *
- * Hack to avoid lots of clocksource churn at boot time.
- * We use fs_initcall because we want this to start before
- * device_initcall but after subsys_initcall.
- */
-static int __init clocksource_done_booting(void)
-{
-        finished_booting = 1;
-        return 0;
-}
-fs_initcall(clocksource_done_booting);
-
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
+static void clocksource_watchdog_work(struct work_struct *work);
+
 static LIST_HEAD(watchdog_list);
 static struct clocksource *watchdog;
 static struct timer_list watchdog_timer;
+static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
 static DEFINE_SPINLOCK(watchdog_lock);
 static cycle_t watchdog_last;
-static unsigned long watchdog_resumed;
+static int watchdog_running;
+
+static int clocksource_watchdog_kthread(void *data);
+static void __clocksource_change_rating(struct clocksource *cs, int rating);
 
 /*
  * Interval: 0.5sec Threshold: 0.0625s
@@ -158,135 +143,249 @@ static unsigned long watchdog_resumed;
 #define WATCHDOG_INTERVAL (HZ >> 1)
 #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4)
 
-static void clocksource_ratewd(struct clocksource *cs, int64_t delta)
+static void clocksource_watchdog_work(struct work_struct *work)
 {
-        if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD)
-                return;
+        /*
+         * If kthread_run fails the next watchdog scan over the
+         * watchdog_list will find the unstable clock again.
+         */
+        kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog");
+}
+
+static void __clocksource_unstable(struct clocksource *cs)
+{
+        cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
+        cs->flags |= CLOCK_SOURCE_UNSTABLE;
+        if (finished_booting)
+                schedule_work(&watchdog_work);
+}
 
+static void clocksource_unstable(struct clocksource *cs, int64_t delta)
+{
         printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n",
                cs->name, delta);
-        cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
-        clocksource_change_rating(cs, 0);
-        list_del(&cs->wd_list);
+        __clocksource_unstable(cs);
+}
+
+/**
+ * clocksource_mark_unstable - mark clocksource unstable via watchdog
+ * @cs:         clocksource to be marked unstable
+ *
+ * This function is called instead of clocksource_change_rating from
+ * cpu hotplug code to avoid a deadlock between the clocksource mutex
+ * and the cpu hotplug mutex. It defers the update of the clocksource
+ * to the watchdog thread.
+ */
+void clocksource_mark_unstable(struct clocksource *cs)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&watchdog_lock, flags);
+        if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {
+                if (list_empty(&cs->wd_list))
+                        list_add(&cs->wd_list, &watchdog_list);
+                __clocksource_unstable(cs);
+        }
+        spin_unlock_irqrestore(&watchdog_lock, flags);
 }
 
 static void clocksource_watchdog(unsigned long data)
 {
-        struct clocksource *cs, *tmp;
+        struct clocksource *cs;
         cycle_t csnow, wdnow;
         int64_t wd_nsec, cs_nsec;
-        int resumed;
+        int next_cpu;
 
         spin_lock(&watchdog_lock);
-
-        resumed = test_and_clear_bit(0, &watchdog_resumed);
+        if (!watchdog_running)
+                goto out;
 
         wdnow = watchdog->read(watchdog);
-        wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
+        wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask,
+                                     watchdog->mult, watchdog->shift);
         watchdog_last = wdnow;
 
-        list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
-                csnow = cs->read(cs);
+        list_for_each_entry(cs, &watchdog_list, wd_list) {
 
-                if (unlikely(resumed)) {
-                        cs->wd_last = csnow;
+                /* Clocksource already marked unstable? */
+                if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
+                        if (finished_booting)
+                                schedule_work(&watchdog_work);
                         continue;
                 }
 
-                /* Initialized ? */
+                csnow = cs->read(cs);
+
+                /* Clocksource initialized ? */
                 if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
-                        if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
-                            (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
-                                cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
-                                /*
-                                 * We just marked the clocksource as
-                                 * highres-capable, notify the rest of the
-                                 * system as well so that we transition
-                                 * into high-res mode:
-                                 */
-                                tick_clock_notify();
-                        }
                         cs->flags |= CLOCK_SOURCE_WATCHDOG;
                         cs->wd_last = csnow;
-                } else {
-                        cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask);
-                        cs->wd_last = csnow;
-                        /* Check the delta. Might remove from the list ! */
-                        clocksource_ratewd(cs, cs_nsec - wd_nsec);
+                        continue;
                 }
-        }
 
-        if (!list_empty(&watchdog_list)) {
-                /*
-                 * Cycle through CPUs to check if the CPUs stay
-                 * synchronized to each other.
-                 */
-                int next_cpu = cpumask_next(raw_smp_processor_id(),
-                                            cpu_online_mask);
+                /* Check the deviation from the watchdog clocksource. */
+                cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
+                                             cs->mask, cs->mult, cs->shift);
+                cs->wd_last = csnow;
+                if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
+                        clocksource_unstable(cs, cs_nsec - wd_nsec);
+                        continue;
+                }
 
-                if (next_cpu >= nr_cpu_ids)
-                        next_cpu = cpumask_first(cpu_online_mask);
-                watchdog_timer.expires += WATCHDOG_INTERVAL;
-                add_timer_on(&watchdog_timer, next_cpu);
+                if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
+                    (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
+                    (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
+                        cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
+                        /*
+                         * We just marked the clocksource as highres-capable,
+                         * notify the rest of the system as well so that we
+                         * transition into high-res mode:
+                         */
+                        tick_clock_notify();
+                }
         }
+
+        /*
+         * Cycle through CPUs to check if the CPUs stay synchronized
+         * to each other.
+         */
+        next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
+        if (next_cpu >= nr_cpu_ids)
+                next_cpu = cpumask_first(cpu_online_mask);
+        watchdog_timer.expires += WATCHDOG_INTERVAL;
+        add_timer_on(&watchdog_timer, next_cpu);
+out:
         spin_unlock(&watchdog_lock);
 }
+
+static inline void clocksource_start_watchdog(void)
+{
+        if (watchdog_running || !watchdog || list_empty(&watchdog_list))
+                return;
+        init_timer(&watchdog_timer);
+        watchdog_timer.function = clocksource_watchdog;
+        watchdog_last = watchdog->read(watchdog);
+        watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
+        add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask));
+        watchdog_running = 1;
+}
+
+static inline void clocksource_stop_watchdog(void)
+{
+        if (!watchdog_running || (watchdog && !list_empty(&watchdog_list)))
+                return;
+        del_timer(&watchdog_timer);
+        watchdog_running = 0;
+}
+
+static inline void clocksource_reset_watchdog(void)
+{
+        struct clocksource *cs;
+
+        list_for_each_entry(cs, &watchdog_list, wd_list)
+                cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
+}
+
 static void clocksource_resume_watchdog(void)
 {
-        set_bit(0, &watchdog_resumed);
+        unsigned long flags;
+
+        spin_lock_irqsave(&watchdog_lock, flags);
+        clocksource_reset_watchdog();
+        spin_unlock_irqrestore(&watchdog_lock, flags);
 }
 
-static void clocksource_check_watchdog(struct clocksource *cs)
+static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
-        struct clocksource *cse;
         unsigned long flags;
 
         spin_lock_irqsave(&watchdog_lock, flags);
         if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
-                int started = !list_empty(&watchdog_list);
-
+                /* cs is a clocksource to be watched. */
                 list_add(&cs->wd_list, &watchdog_list);
-                if (!started && watchdog) {
-                        watchdog_last = watchdog->read(watchdog);
-                        watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
-                        add_timer_on(&watchdog_timer,
-                                     cpumask_first(cpu_online_mask));
-                }
+                cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
         } else {
+                /* cs is a watchdog. */
                 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
                         cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
-
+                /* Pick the best watchdog. */
                 if (!watchdog || cs->rating > watchdog->rating) {
-                        if (watchdog)
-                                del_timer(&watchdog_timer);
                         watchdog = cs;
-                        init_timer(&watchdog_timer);
-                        watchdog_timer.function = clocksource_watchdog;
-
                         /* Reset watchdog cycles */
-                        list_for_each_entry(cse, &watchdog_list, wd_list)
-                                cse->flags &= ~CLOCK_SOURCE_WATCHDOG;
-                        /* Start if list is not empty */
-                        if (!list_empty(&watchdog_list)) {
-                                watchdog_last = watchdog->read(watchdog);
-                                watchdog_timer.expires =
-                                        jiffies + WATCHDOG_INTERVAL;
-                                add_timer_on(&watchdog_timer,
-                                             cpumask_first(cpu_online_mask));
-                        }
+                        clocksource_reset_watchdog();
+                }
+        }
+        /* Check if the watchdog timer needs to be started. */
+        clocksource_start_watchdog();
+        spin_unlock_irqrestore(&watchdog_lock, flags);
+}
+
+static void clocksource_dequeue_watchdog(struct clocksource *cs)
+{
+        struct clocksource *tmp;
+        unsigned long flags;
+
+        spin_lock_irqsave(&watchdog_lock, flags);
+        if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
+                /* cs is a watched clocksource. */
+                list_del_init(&cs->wd_list);
+        } else if (cs == watchdog) {
+                /* Reset watchdog cycles */
+                clocksource_reset_watchdog();
+                /* Current watchdog is removed. Find an alternative. */
+                watchdog = NULL;
+                list_for_each_entry(tmp, &clocksource_list, list) {
+                        if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY)
+                                continue;
+                        if (!watchdog || tmp->rating > watchdog->rating)
+                                watchdog = tmp;
                 }
         }
+        cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
+        /* Check if the watchdog timer needs to be stopped. */
+        clocksource_stop_watchdog();
         spin_unlock_irqrestore(&watchdog_lock, flags);
 }
-#else
-static void clocksource_check_watchdog(struct clocksource *cs)
+
+static int clocksource_watchdog_kthread(void *data)
+{
+        struct clocksource *cs, *tmp;
+        unsigned long flags;
+        LIST_HEAD(unstable);
+
+        mutex_lock(&clocksource_mutex);
+        spin_lock_irqsave(&watchdog_lock, flags);
+        list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list)
+                if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
+                        list_del_init(&cs->wd_list);
+                        list_add(&cs->wd_list, &unstable);
+                }
+        /* Check if the watchdog timer needs to be stopped. */
+        clocksource_stop_watchdog();
+        spin_unlock_irqrestore(&watchdog_lock, flags);
+
+        /* Needs to be done outside of watchdog lock */
+        list_for_each_entry_safe(cs, tmp, &unstable, wd_list) {
+                list_del_init(&cs->wd_list);
+                __clocksource_change_rating(cs, 0);
+        }
+        mutex_unlock(&clocksource_mutex);
+        return 0;
+}
+
+#else /* CONFIG_CLOCKSOURCE_WATCHDOG */
+
+static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
         if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
                 cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
 }
 
+static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
 static inline void clocksource_resume_watchdog(void) { }
-#endif
+static inline int clocksource_watchdog_kthread(void *data) { return 0; }
+
+#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
 
 /**
  * clocksource_resume - resume the clocksource(s)
@@ -294,18 +393,12 @@ static inline void clocksource_resume_watchdog(void) { }
 void clocksource_resume(void)
 {
         struct clocksource *cs;
-        unsigned long flags;
 
-        spin_lock_irqsave(&clocksource_lock, flags);
-
-        list_for_each_entry(cs, &clocksource_list, list) {
+        list_for_each_entry(cs, &clocksource_list, list)
                 if (cs->resume)
                         cs->resume();
-        }
 
         clocksource_resume_watchdog();
-
-        spin_unlock_irqrestore(&clocksource_lock, flags);
 }
 
 /**
@@ -320,75 +413,94 @@ void clocksource_touch_watchdog(void)
         clocksource_resume_watchdog();
 }
 
+#ifdef CONFIG_GENERIC_TIME
+
 /**
- * clocksource_get_next - Returns the selected clocksource
+ * clocksource_select - Select the best clocksource available
  *
+ * Private function. Must hold clocksource_mutex when called.
+ *
+ * Select the clocksource with the best rating, or the clocksource,
+ * which is selected by userspace override.
  */
-struct clocksource *clocksource_get_next(void)
+static void clocksource_select(void)
 {
-        unsigned long flags;
+        struct clocksource *best, *cs;
 
-        spin_lock_irqsave(&clocksource_lock, flags);
-        if (next_clocksource && finished_booting) {
-                curr_clocksource = next_clocksource;
-                next_clocksource = NULL;
+        if (!finished_booting || list_empty(&clocksource_list))
+                return;
+        /* First clocksource on the list has the best rating. */
+        best = list_first_entry(&clocksource_list, struct clocksource, list);
+        /* Check for the override clocksource. */
+        list_for_each_entry(cs, &clocksource_list, list) {
+                if (strcmp(cs->name, override_name) != 0)
+                        continue;
+                /*
+                 * Check to make sure we don't switch to a non-highres
+                 * capable clocksource if the tick code is in oneshot
+                 * mode (highres or nohz)
+                 */
+                if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
+                    tick_oneshot_mode_active()) {
+                        /* Override clocksource cannot be used. */
+                        printk(KERN_WARNING "Override clocksource %s is not "
+                               "HRT compatible. Cannot switch while in "
+                               "HRT/NOHZ mode\n", cs->name);
+                        override_name[0] = 0;
+                } else
+                        /* Override clocksource can be used. */
+                        best = cs;
+                break;
+        }
+        if (curr_clocksource != best) {
+                printk(KERN_INFO "Switching to clocksource %s\n", best->name);
+                curr_clocksource = best;
+                timekeeping_notify(curr_clocksource);
         }
-        spin_unlock_irqrestore(&clocksource_lock, flags);
-
-        return curr_clocksource;
 }
 
-/**
- * select_clocksource - Selects the best registered clocksource.
- *
- * Private function. Must hold clocksource_lock when called.
+#else /* CONFIG_GENERIC_TIME */
+
+static inline void clocksource_select(void) { }
+
+#endif
+
+/*
+ * clocksource_done_booting - Called near the end of core bootup
  *
- * Select the clocksource with the best rating, or the clocksource,
- * which is selected by userspace override.
+ * Hack to avoid lots of clocksource churn at boot time.
+ * We use fs_initcall because we want this to start before
+ * device_initcall but after subsys_initcall.
  */
-static struct clocksource *select_clocksource(void)
+static int __init clocksource_done_booting(void)
 {
-        struct clocksource *next;
-
-        if (list_empty(&clocksource_list))
-                return NULL;
-
-        if (clocksource_override)
-                next = clocksource_override;
-        else
-                next = list_entry(clocksource_list.next, struct clocksource,
-                                  list);
+        finished_booting = 1;
 
-        if (next == curr_clocksource)
-                return NULL;
+        /*
+         * Run the watchdog first to eliminate unstable clock sources
+         */
+        clocksource_watchdog_kthread(NULL);
 
-        return next;
+        mutex_lock(&clocksource_mutex);
+        clocksource_select();
+        mutex_unlock(&clocksource_mutex);
+        return 0;
 }
+fs_initcall(clocksource_done_booting);
 
 /*
  * Enqueue the clocksource sorted by rating
  */
-static int clocksource_enqueue(struct clocksource *c)
+static void clocksource_enqueue(struct clocksource *cs)
 {
-        struct list_head *tmp, *entry = &clocksource_list;
+        struct list_head *entry = &clocksource_list;
+        struct clocksource *tmp;
 
-        list_for_each(tmp, &clocksource_list) {
-                struct clocksource *cs;
-
-                cs = list_entry(tmp, struct clocksource, list);
-                if (cs == c)
-                        return -EBUSY;
+        list_for_each_entry(tmp, &clocksource_list, list)
                 /* Keep track of the place, where to insert */
-                if (cs->rating >= c->rating)
-                        entry = tmp;
-        }
-        list_add(&c->list, entry);
-
-        if (strlen(c->name) == strlen(override_name) &&
-            !strcmp(c->name, override_name))
-                clocksource_override = c;
-
-        return 0;
+                if (tmp->rating >= cs->rating)
+                        entry = &tmp->list;
+        list_add(&cs->list, entry);
 }
 
 /**
@@ -397,52 +509,48 @@ static int clocksource_enqueue(struct clocksource *c)
  *
  * Returns -EBUSY if registration fails, zero otherwise.
  */
-int clocksource_register(struct clocksource *c)
+int clocksource_register(struct clocksource *cs)
 {
-        unsigned long flags;
-        int ret;
-
-        spin_lock_irqsave(&clocksource_lock, flags);
-        ret = clocksource_enqueue(c);
-        if (!ret)
-                next_clocksource = select_clocksource();
-        spin_unlock_irqrestore(&clocksource_lock, flags);
-        if (!ret)
-                clocksource_check_watchdog(c);
-        return ret;
+        mutex_lock(&clocksource_mutex);
+        clocksource_enqueue(cs);
+        clocksource_select();
+        clocksource_enqueue_watchdog(cs);
+        mutex_unlock(&clocksource_mutex);
+        return 0;
 }
 EXPORT_SYMBOL(clocksource_register);
 
+static void __clocksource_change_rating(struct clocksource *cs, int rating)
+{
+        list_del(&cs->list);
+        cs->rating = rating;
+        clocksource_enqueue(cs);
+        clocksource_select();
+}
+
 /**
  * clocksource_change_rating - Change the rating of a registered clocksource
- *
  */
 void clocksource_change_rating(struct clocksource *cs, int rating)
 {
-        unsigned long flags;
-
-        spin_lock_irqsave(&clocksource_lock, flags);
-        list_del(&cs->list);
-        cs->rating = rating;
-        clocksource_enqueue(cs);
-        next_clocksource = select_clocksource();
-        spin_unlock_irqrestore(&clocksource_lock, flags);
+        mutex_lock(&clocksource_mutex);
+        __clocksource_change_rating(cs, rating);
+        mutex_unlock(&clocksource_mutex);
 }
+EXPORT_SYMBOL(clocksource_change_rating);
 
 /**
  * clocksource_unregister - remove a registered clocksource
  */
 void clocksource_unregister(struct clocksource *cs)
 {
-        unsigned long flags;
-
-        spin_lock_irqsave(&clocksource_lock, flags);
+        mutex_lock(&clocksource_mutex);
+        clocksource_dequeue_watchdog(cs);
         list_del(&cs->list);
-        if (clocksource_override == cs)
-                clocksource_override = NULL;
-        next_clocksource = select_clocksource();
-        spin_unlock_irqrestore(&clocksource_lock, flags);
+        clocksource_select();
+        mutex_unlock(&clocksource_mutex);
 }
+EXPORT_SYMBOL(clocksource_unregister);
 
 #ifdef CONFIG_SYSFS
 /**
@@ -458,9 +566,9 @@ sysfs_show_current_clocksources(struct sys_device *dev,
 {
         ssize_t count = 0;
 
-        spin_lock_irq(&clocksource_lock);
+        mutex_lock(&clocksource_mutex);
         count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name);
-        spin_unlock_irq(&clocksource_lock);
+        mutex_unlock(&clocksource_mutex);
 
         return count;
 }
@@ -478,9 +586,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
                                           struct sysdev_attribute *attr,
                                           const char *buf, size_t count)
 {
-        struct clocksource *ovr = NULL;
         size_t ret = count;
-        int len;
 
         /* strings from sysfs write are not 0 terminated! */
         if (count >= sizeof(override_name))
@@ -490,44 +596,14 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
         if (buf[count-1] == '\n')
                 count--;
 
-        spin_lock_irq(&clocksource_lock);
+        mutex_lock(&clocksource_mutex);
 
         if (count > 0)
                 memcpy(override_name, buf, count);
         override_name[count] = 0;
+        clocksource_select();
 
-        len = strlen(override_name);
-        if (len) {
-                struct clocksource *cs;
-
-                ovr = clocksource_override;
-                /* try to select it: */
-                list_for_each_entry(cs, &clocksource_list, list) {
-                        if (strlen(cs->name) == len &&
-                            !strcmp(cs->name, override_name))
-                                ovr = cs;
-                }
-        }
-
-        /*
-         * Check to make sure we don't switch to a non-highres capable
-         * clocksource if the tick code is in oneshot mode (highres or nohz)
-         */
-        if (tick_oneshot_mode_active() && ovr &&
-            !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
-                printk(KERN_WARNING "%s clocksource is not HRT compatible. "
-                        "Cannot switch while in HRT/NOHZ mode\n", ovr->name);
-                ovr = NULL;
-                override_name[0] = 0;
-        }
-
-        /* Reselect, when the override name has changed */
-        if (ovr != clocksource_override) {
-                clocksource_override = ovr;
-                next_clocksource = select_clocksource();
-        }
-
-        spin_unlock_irq(&clocksource_lock);
+        mutex_unlock(&clocksource_mutex);
 
         return ret;
 }
@@ -547,7 +623,7 @@ sysfs_show_available_clocksources(struct sys_device *dev,
         struct clocksource *src;
         ssize_t count = 0;
 
-        spin_lock_irq(&clocksource_lock);
+        mutex_lock(&clocksource_mutex);
         list_for_each_entry(src, &clocksource_list, list) {
                 /*
                  * Don't show non-HRES clocksource if the tick code is
@@ -559,7 +635,7 @@ sysfs_show_available_clocksources(struct sys_device *dev,
                                   max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
                                   "%s ", src->name);
         }
-        spin_unlock_irq(&clocksource_lock);
+        mutex_unlock(&clocksource_mutex);
 
         count += snprintf(buf + count,
                           max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n");
@@ -614,11 +690,10 @@ device_initcall(init_clocksource_sysfs);
  */
 static int __init boot_override_clocksource(char* str)
 {
-        unsigned long flags;
-        spin_lock_irqsave(&clocksource_lock, flags);
+        mutex_lock(&clocksource_mutex);
         if (str)
                 strlcpy(override_name, str, sizeof(override_name));
-        spin_unlock_irqrestore(&clocksource_lock, flags);
+        mutex_unlock(&clocksource_mutex);
         return 1;
 }
 
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index c3f6c30816e3..5404a8456909 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -61,7 +61,6 @@ struct clocksource clocksource_jiffies = {
         .read           = jiffies_read,
         .mask           = 0xffffffff, /*32bits*/
         .mult           = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
-        .mult_orig      = NSEC_PER_JIFFY << JIFFIES_SHIFT,
         .shift          = JIFFIES_SHIFT,
 };
 
@@ -71,3 +70,8 @@ static int __init init_jiffies_clocksource(void)
 }
 
 core_initcall(init_jiffies_clocksource);
+
+struct clocksource * __init __weak clocksource_default_clock(void)
+{
+        return &clocksource_jiffies;
+}
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 7fc64375ff43..4800f933910e 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -194,8 +194,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
         case TIME_OK:
                 break;
         case TIME_INS:
-                xtime.tv_sec--;
-                wall_to_monotonic.tv_sec++;
+                timekeeping_leap_insert(-1);
                 time_state = TIME_OOP;
                 printk(KERN_NOTICE
                         "Clock: inserting leap second 23:59:60 UTC\n");
@@ -203,9 +202,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
                 res = HRTIMER_RESTART;
                 break;
         case TIME_DEL:
-                xtime.tv_sec++;
+                timekeeping_leap_insert(1);
                 time_tai--;
-                wall_to_monotonic.tv_sec--;
                 time_state = TIME_WAIT;
                 printk(KERN_NOTICE
                         "Clock: deleting leap second 23:59:59 UTC\n");
@@ -219,7 +217,6 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
                         time_state = TIME_OK;
                 break;
         }
-        update_vsyscall(&xtime, clock);
 
         write_sequnlock(&xtime_lock);
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e0f59a21c061..89aed5933ed4 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -231,6 +231,13 @@ void tick_nohz_stop_sched_tick(int inidle)
         if (!inidle && !ts->inidle)
                 goto end;
 
+        /*
+         * Set ts->inidle unconditionally. Even if the system did not
+         * switch to NOHZ mode the cpu frequency governers rely on the
+         * update of the idle time accounting in tick_nohz_start_idle().
+         */
+        ts->inidle = 1;
+
         now = tick_nohz_start_idle(ts);
 
         /*
@@ -248,8 +255,6 @@ void tick_nohz_stop_sched_tick(int inidle)
         if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
                 goto end;
 
-        ts->inidle = 1;
-
         if (need_resched())
                 goto end;
 
diff --git a/kernel/time/timeconv.c b/kernel/time/timeconv.c
new file mode 100644
index 000000000000..86628e755f38
--- /dev/null
+++ b/kernel/time/timeconv.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ * Contributed by Paul Eggert (eggert@twinsun.com).
+ *
+ * The GNU C Library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * The GNU C Library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with the GNU C Library; see the file COPYING.LIB.  If not,
+ * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/*
+ * Converts the calendar time to broken-down time representation
+ * Based on code from glibc-2.6
+ *
+ * 2009-7-14:
+ *   Moved from glibc-2.6 to kernel by Zhaolei<zhaolei@cn.fujitsu.com>
+ */
+
+#include <linux/time.h>
+#include <linux/module.h>
+
+/*
+ * Nonzero if YEAR is a leap year (every 4 years,
+ * except every 100th isn't, and every 400th is).
+ */
+static int __isleap(long year)
+{
+        return (year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0);
+}
+
+/* do a mathdiv for long type */
+static long math_div(long a, long b)
+{
+        return a / b - (a % b < 0);
+}
+
+/* How many leap years between y1 and y2, y1 must less or equal to y2 */
+static long leaps_between(long y1, long y2)
+{
+        long leaps1 = math_div(y1 - 1, 4) - math_div(y1 - 1, 100)
+                + math_div(y1 - 1, 400);
+        long leaps2 = math_div(y2 - 1, 4) - math_div(y2 - 1, 100)
+                + math_div(y2 - 1, 400);
+        return leaps2 - leaps1;
+}
+
+/* How many days come before each month (0-12). */
+static const unsigned short __mon_yday[2][13] = {
+        /* Normal years. */
+        {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
+        /* Leap years. */
+        {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
+};
+
+#define SECS_PER_HOUR   (60 * 60)
+#define SECS_PER_DAY    (SECS_PER_HOUR * 24)
+
+/**
+ * time_to_tm - converts the calendar time to local broken-down time
+ *
+ * @totalsecs   the number of seconds elapsed since 00:00:00 on January 1, 1970,
+ *              Coordinated Universal Time (UTC).
+ * @offset      offset seconds adding to totalsecs.
+ * @result      pointer to struct tm variable to receive broken-down time
+ */
+void time_to_tm(time_t totalsecs, int offset, struct tm *result)
+{
+        long days, rem, y;
+        const unsigned short *ip;
+
+        days = totalsecs / SECS_PER_DAY;
+        rem = totalsecs % SECS_PER_DAY;
+        rem += offset;
+        while (rem < 0) {
+                rem += SECS_PER_DAY;
+                --days;
+        }
+        while (rem >= SECS_PER_DAY) {
+                rem -= SECS_PER_DAY;
+                ++days;
+        }
+
+        result->tm_hour = rem / SECS_PER_HOUR;
+        rem %= SECS_PER_HOUR;
+        result->tm_min = rem / 60;
+        result->tm_sec = rem % 60;
+
+        /* January 1, 1970 was a Thursday. */
+        result->tm_wday = (4 + days) % 7;
+        if (result->tm_wday < 0)
+                result->tm_wday += 7;
+
+        y = 1970;
+
+        while (days < 0 || days >= (__isleap(y) ? 366 : 365)) {
+                /* Guess a corrected year, assuming 365 days per year. */
+                long yg = y + math_div(days, 365);
+
+                /* Adjust DAYS and Y to match the guessed year. */
+                days -= (yg - y) * 365 + leaps_between(y, yg);
+                y = yg;
+        }
+
+        result->tm_year = y - 1900;
+
+        result->tm_yday = days;
+
+        ip = __mon_yday[__isleap(y)];
+        for (y = 11; days < ip[y]; y--)
+                continue;
+        days -= ip[y];
+
+        result->tm_mon = y;
+        result->tm_mday = days + 1;
+}
+EXPORT_SYMBOL(time_to_tm);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e8c77d9c633a..c3a4e2907eaa 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -13,12 +13,123 @@
 #include <linux/percpu.h>
 #include <linux/init.h>
 #include <linux/mm.h>
+#include <linux/sched.h>
 #include <linux/sysdev.h>
 #include <linux/clocksource.h>
 #include <linux/jiffies.h>
 #include <linux/time.h>
 #include <linux/tick.h>
+#include <linux/stop_machine.h>
+
+/* Structure holding internal timekeeping values. */
+struct timekeeper {
+        /* Current clocksource used for timekeeping. */
+        struct clocksource *clock;
+        /* The shift value of the current clocksource. */
+        int     shift;
+
+        /* Number of clock cycles in one NTP interval. */
+        cycle_t cycle_interval;
+        /* Number of clock shifted nano seconds in one NTP interval. */
+        u64     xtime_interval;
+        /* Raw nano seconds accumulated per NTP interval. */
+        u32     raw_interval;
+
+        /* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */
+        u64     xtime_nsec;
+        /* Difference between accumulated time and NTP time in ntp
+         * shifted nano seconds. */
+        s64     ntp_error;
+        /* Shift conversion between clock shifted nano seconds and
+         * ntp shifted nano seconds. */
+        int     ntp_error_shift;
+        /* NTP adjusted clock multiplier */
+        u32     mult;
+};
+
+struct timekeeper timekeeper;
+
+/**
+ * timekeeper_setup_internals - Set up internals to use clocksource clock.
+ *
+ * @clock:              Pointer to clocksource.
+ *
+ * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
+ * pair and interval request.
+ *
+ * Unless you're the timekeeping code, you should not be using this!
+ */
+static void timekeeper_setup_internals(struct clocksource *clock)
+{
+        cycle_t interval;
+        u64 tmp;
+
+        timekeeper.clock = clock;
+        clock->cycle_last = clock->read(clock);
 
+        /* Do the ns -> cycle conversion first, using original mult */
+        tmp = NTP_INTERVAL_LENGTH;
+        tmp <<= clock->shift;
+        tmp += clock->mult/2;
+        do_div(tmp, clock->mult);
+        if (tmp == 0)
+                tmp = 1;
+
+        interval = (cycle_t) tmp;
+        timekeeper.cycle_interval = interval;
+
+        /* Go back from cycles -> shifted ns */
+        timekeeper.xtime_interval = (u64) interval * clock->mult;
+        timekeeper.raw_interval =
+                ((u64) interval * clock->mult) >> clock->shift;
+
+        timekeeper.xtime_nsec = 0;
+        timekeeper.shift = clock->shift;
+
+        timekeeper.ntp_error = 0;
+        timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
+
+        /*
+         * The timekeeper keeps its own mult values for the currently
+         * active clocksource. These value will be adjusted via NTP
+         * to counteract clock drifting.
+         */
+        timekeeper.mult = clock->mult;
+}
+
+/* Timekeeper helper functions. */
+static inline s64 timekeeping_get_ns(void)
+{
+        cycle_t cycle_now, cycle_delta;
+        struct clocksource *clock;
+
+        /* read clocksource: */
+        clock = timekeeper.clock;
+        cycle_now = clock->read(clock);
+
+        /* calculate the delta since the last update_wall_time: */
+        cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+        /* return delta convert to nanoseconds using ntp adjusted mult. */
+        return clocksource_cyc2ns(cycle_delta, timekeeper.mult,
+                                  timekeeper.shift);
+}
+
+static inline s64 timekeeping_get_ns_raw(void)
+{
+        cycle_t cycle_now, cycle_delta;
+        struct clocksource *clock;
+
+        /* read clocksource: */
+        clock = timekeeper.clock;
+        cycle_now = clock->read(clock);
+
+        /* calculate the delta since the last update_wall_time: */
+        cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+        /* return delta convert to nanoseconds using ntp adjusted mult. */
+        return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+}
 
 /*
  * This read-write spinlock protects us from races in SMP while
@@ -44,7 +155,12 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
  */
 struct timespec xtime __attribute__ ((aligned (16)));
 struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
-static unsigned long total_sleep_time;          /* seconds */
+static struct timespec total_sleep_time;
+
+/*
+ * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
+ */
+struct timespec raw_time;
 
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
@@ -56,35 +172,44 @@ void update_xtime_cache(u64 nsec)
         timespec_add_ns(&xtime_cache, nsec);
 }
 
-struct clocksource *clock;
-
+/* must hold xtime_lock */
+void timekeeping_leap_insert(int leapsecond)
+{
+        xtime.tv_sec += leapsecond;
+        wall_to_monotonic.tv_sec -= leapsecond;
+        update_vsyscall(&xtime, timekeeper.clock);
+}
 
 #ifdef CONFIG_GENERIC_TIME
+
 /**
- * clocksource_forward_now - update clock to the current time
+ * timekeeping_forward_now - update clock to the current time
  *
  * Forward the current clock to update its state since the last call to
  * update_wall_time(). This is useful before significant clock changes,
  * as it avoids having to deal with this time offset explicitly.
  */
-static void clocksource_forward_now(void)
+static void timekeeping_forward_now(void)
 {
         cycle_t cycle_now, cycle_delta;
+        struct clocksource *clock;
         s64 nsec;
 
-        cycle_now = clocksource_read(clock);
+        clock = timekeeper.clock;
+        cycle_now = clock->read(clock);
         cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
         clock->cycle_last = cycle_now;
 
-        nsec = cyc2ns(clock, cycle_delta);
+        nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult,
+                                  timekeeper.shift);
 
         /* If arch requires, add in gettimeoffset() */
         nsec += arch_gettimeoffset();
 
         timespec_add_ns(&xtime, nsec);
 
-        nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
-        clock->raw_time.tv_nsec += nsec;
+        nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+        timespec_add_ns(&raw_time, nsec);
 }
 
 /**
@@ -95,7 +220,6 @@ static void clocksource_forward_now(void)
  */
 void getnstimeofday(struct timespec *ts)
 {
-        cycle_t cycle_now, cycle_delta;
         unsigned long seq;
         s64 nsecs;
 
@@ -105,15 +229,7 @@ void getnstimeofday(struct timespec *ts)
                 seq = read_seqbegin(&xtime_lock);
 
                 *ts = xtime;
-
-                /* read clocksource: */
-                cycle_now = clocksource_read(clock);
-
-                /* calculate the delta since the last update_wall_time: */
-                cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
-
-                /* convert to nanoseconds: */
-                nsecs = cyc2ns(clock, cycle_delta);
+                nsecs = timekeeping_get_ns();
 
                 /* If arch requires, add in gettimeoffset() */
                 nsecs += arch_gettimeoffset();
@@ -125,6 +241,57 @@ void getnstimeofday(struct timespec *ts)
 
 EXPORT_SYMBOL(getnstimeofday);
 
+ktime_t ktime_get(void)
+{
+        unsigned int seq;
+        s64 secs, nsecs;
+
+        WARN_ON(timekeeping_suspended);
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+                secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
+                nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
+                nsecs += timekeeping_get_ns();
+
+        } while (read_seqretry(&xtime_lock, seq));
+        /*
+         * Use ktime_set/ktime_add_ns to create a proper ktime on
+         * 32-bit architectures without CONFIG_KTIME_SCALAR.
+         */
+        return ktime_add_ns(ktime_set(secs, 0), nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get);
+
+/**
+ * ktime_get_ts - get the monotonic clock in timespec format
+ * @ts:         pointer to timespec variable
+ *
+ * The function calculates the monotonic clock from the realtime
+ * clock and the wall_to_monotonic offset and stores the result
+ * in normalized timespec format in the variable pointed to by @ts.
+ */
+void ktime_get_ts(struct timespec *ts)
+{
+        struct timespec tomono;
+        unsigned int seq;
+        s64 nsecs;
+
+        WARN_ON(timekeeping_suspended);
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+                *ts = xtime;
+                tomono = wall_to_monotonic;
+                nsecs = timekeeping_get_ns();
+
+        } while (read_seqretry(&xtime_lock, seq));
+
+        set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
+                                ts->tv_nsec + tomono.tv_nsec + nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get_ts);
+
 /**
  * do_gettimeofday - Returns the time of day in a timeval
  * @tv:         pointer to the timeval to be set
@@ -157,7 +324,7 @@ int do_settimeofday(struct timespec *tv)
 
         write_seqlock_irqsave(&xtime_lock, flags);
 
-        clocksource_forward_now();
+        timekeeping_forward_now();
 
         ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec;
         ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec;
@@ -167,10 +334,10 @@ int do_settimeofday(struct timespec *tv)
 
         update_xtime_cache(0);
 
-        clock->error = 0;
+        timekeeper.ntp_error = 0;
         ntp_clear();
 
-        update_vsyscall(&xtime, clock);
+        update_vsyscall(&xtime, timekeeper.clock);
 
         write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -187,44 +354,97 @@ EXPORT_SYMBOL(do_settimeofday);
  *
  * Accumulates current time interval and initializes new clocksource
  */
-static void change_clocksource(void)
+static int change_clocksource(void *data)
 {
         struct clocksource *new, *old;
 
-        new = clocksource_get_next();
+        new = (struct clocksource *) data;
+
+        timekeeping_forward_now();
+        if (!new->enable || new->enable(new) == 0) {
+                old = timekeeper.clock;
+                timekeeper_setup_internals(new);
+                if (old->disable)
+                        old->disable(old);
+        }
+        return 0;
+}
 
-        if (clock == new)
+/**
+ * timekeeping_notify - Install a new clock source
+ * @clock:              pointer to the clock source
+ *
+ * This function is called from clocksource.c after a new, better clock
+ * source has been registered. The caller holds the clocksource_mutex.
+ */
+void timekeeping_notify(struct clocksource *clock)
+{
+        if (timekeeper.clock == clock)
                 return;
+        stop_machine(change_clocksource, clock, NULL);
+        tick_clock_notify();
+}
 
-        clocksource_forward_now();
+#else /* GENERIC_TIME */
 
-        if (clocksource_enable(new))
-                return;
+static inline void timekeeping_forward_now(void) { }
 
-        new->raw_time = clock->raw_time;
-        old = clock;
-        clock = new;
-        clocksource_disable(old);
+/**
+ * ktime_get - get the monotonic time in ktime_t format
+ *
+ * returns the time in ktime_t format
+ */
+ktime_t ktime_get(void)
+{
+        struct timespec now;
 
-        clock->cycle_last = 0;
-        clock->cycle_last = clocksource_read(clock);
-        clock->error = 0;
-        clock->xtime_nsec = 0;
-        clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
+        ktime_get_ts(&now);
 
-        tick_clock_notify();
+        return timespec_to_ktime(now);
+}
+EXPORT_SYMBOL_GPL(ktime_get);
 
-        /*
-         * We're holding xtime lock and waking up klogd would deadlock
-         * us on enqueue.  So no printing!
-        printk(KERN_INFO "Time: %s clocksource has been installed.\n",
-               clock->name);
-         */
+/**
+ * ktime_get_ts - get the monotonic clock in timespec format
+ * @ts:         pointer to timespec variable
+ *
+ * The function calculates the monotonic clock from the realtime
+ * clock and the wall_to_monotonic offset and stores the result
+ * in normalized timespec format in the variable pointed to by @ts.
+ */
+void ktime_get_ts(struct timespec *ts)
+{
+        struct timespec tomono;
+        unsigned long seq;
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+                getnstimeofday(ts);
+                tomono = wall_to_monotonic;
+
+        } while (read_seqretry(&xtime_lock, seq));
+
+        set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
+                                ts->tv_nsec + tomono.tv_nsec);
 }
-#else
-static inline void clocksource_forward_now(void) { }
-static inline void change_clocksource(void) { }
-#endif
+EXPORT_SYMBOL_GPL(ktime_get_ts);
+
+#endif /* !GENERIC_TIME */
+
+/**
+ * ktime_get_real - get the real (wall-) time in ktime_t format
+ *
+ * returns the time in ktime_t format
+ */
+ktime_t ktime_get_real(void)
+{
+        struct timespec now;
+
+        getnstimeofday(&now);
+
+        return timespec_to_ktime(now);
+}
+EXPORT_SYMBOL_GPL(ktime_get_real);
 
 /**
  * getrawmonotonic - Returns the raw monotonic time in a timespec
@@ -236,21 +456,11 @@ void getrawmonotonic(struct timespec *ts)
 {
         unsigned long seq;
         s64 nsecs;
-        cycle_t cycle_now, cycle_delta;
 
         do {
                 seq = read_seqbegin(&xtime_lock);
-
-                /* read clocksource: */
-                cycle_now = clocksource_read(clock);
-
-                /* calculate the delta since the last update_wall_time: */
-                cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
-
-                /* convert to nanoseconds: */
-                nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
-
-                *ts = clock->raw_time;
+                nsecs = timekeeping_get_ns_raw();
+                *ts = raw_time;
 
         } while (read_seqretry(&xtime_lock, seq));
 
@@ -270,7 +480,7 @@ int timekeeping_valid_for_hres(void)
         do {
                 seq = read_seqbegin(&xtime_lock);
 
-                ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+                ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
         } while (read_seqretry(&xtime_lock, seq));
 
@@ -278,17 +488,33 @@ int timekeeping_valid_for_hres(void)
 }
 
 /**
- * read_persistent_clock -  Return time in seconds from the persistent clock.
+ * read_persistent_clock -  Return time from the persistent clock.
  *
  * Weak dummy function for arches that do not yet support it.
- * Returns seconds from epoch using the battery backed persistent clock.
- * Returns zero if unsupported.
+ * Reads the time from the battery backed persistent clock.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
  *
  *  XXX - Do be sure to remove it once all arches implement it.
  */
-unsigned long __attribute__((weak)) read_persistent_clock(void)
+void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
 {
-        return 0;
+        ts->tv_sec = 0;
+        ts->tv_nsec = 0;
+}
+
+/**
+ * read_boot_clock -  Return time of the system start.
+ *
+ * Weak dummy function for arches that do not yet support it.
+ * Function to read the exact time the system has been started.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
+ *
+ *  XXX - Do be sure to remove it once all arches implement it.
+ */
+void __attribute__((weak)) read_boot_clock(struct timespec *ts)
+{
+        ts->tv_sec = 0;
+        ts->tv_nsec = 0;
 }
 
 /*
@@ -296,29 +522,40 @@ unsigned long __attribute__((weak)) read_persistent_clock(void)
  */
 void __init timekeeping_init(void)
 {
+        struct clocksource *clock;
         unsigned long flags;
-        unsigned long sec = read_persistent_clock();
+        struct timespec now, boot;
+
+        read_persistent_clock(&now);
+        read_boot_clock(&boot);
 
         write_seqlock_irqsave(&xtime_lock, flags);
 
         ntp_init();
 
-        clock = clocksource_get_next();
-        clocksource_enable(clock);
-        clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
-        clock->cycle_last = clocksource_read(clock);
-
-        xtime.tv_sec = sec;
-        xtime.tv_nsec = 0;
+        clock = clocksource_default_clock();
+        if (clock->enable)
+                clock->enable(clock);
+        timekeeper_setup_internals(clock);
+
+        xtime.tv_sec = now.tv_sec;
+        xtime.tv_nsec = now.tv_nsec;
+        raw_time.tv_sec = 0;
+        raw_time.tv_nsec = 0;
+        if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
+                boot.tv_sec = xtime.tv_sec;
+                boot.tv_nsec = xtime.tv_nsec;
+        }
         set_normalized_timespec(&wall_to_monotonic,
-                -xtime.tv_sec, -xtime.tv_nsec);
+                                -boot.tv_sec, -boot.tv_nsec);
         update_xtime_cache(0);
-        total_sleep_time = 0;
+        total_sleep_time.tv_sec = 0;
+        total_sleep_time.tv_nsec = 0;
         write_sequnlock_irqrestore(&xtime_lock, flags);
 }
 
 /* time in seconds when suspend began */
-static unsigned long timekeeping_suspend_time;
+static struct timespec timekeeping_suspend_time;
 
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
@@ -331,24 +568,24 @@ static unsigned long timekeeping_suspend_time;
 static int timekeeping_resume(struct sys_device *dev)
 {
         unsigned long flags;
-        unsigned long now = read_persistent_clock();
+        struct timespec ts;
+
+        read_persistent_clock(&ts);
 
         clocksource_resume();
 
         write_seqlock_irqsave(&xtime_lock, flags);
 
-        if (now && (now > timekeeping_suspend_time)) {
-                unsigned long sleep_length = now - timekeeping_suspend_time;
-
-                xtime.tv_sec += sleep_length;
-                wall_to_monotonic.tv_sec -= sleep_length;
-                total_sleep_time += sleep_length;
+        if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
+                ts = timespec_sub(ts, timekeeping_suspend_time);
+                xtime = timespec_add_safe(xtime, ts);
+                wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
+                total_sleep_time = timespec_add_safe(total_sleep_time, ts);
         }
         update_xtime_cache(0);
         /* re-base the last cycle value */
-        clock->cycle_last = 0;
-        clock->cycle_last = clocksource_read(clock);
-        clock->error = 0;
+        timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
+        timekeeper.ntp_error = 0;
         timekeeping_suspended = 0;
         write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -366,10 +603,10 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
 {
         unsigned long flags;
 
-        timekeeping_suspend_time = read_persistent_clock();
+        read_persistent_clock(&timekeeping_suspend_time);
 
         write_seqlock_irqsave(&xtime_lock, flags);
-        clocksource_forward_now();
+        timekeeping_forward_now();
         timekeeping_suspended = 1;
         write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -404,7 +641,7 @@ device_initcall(timekeeping_init_device);
  * If the error is already larger, we look ahead even further
  * to compensate for late or lost adjustments.
  */
-static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
+static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
                                                  s64 *offset)
 {
         s64 tick_error, i;
@@ -420,7 +657,7 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
          * here.  This is tuned so that an error of about 1 msec is adjusted
          * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
          */
-        error2 = clock->error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
+        error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
         error2 = abs(error2);
         for (look_ahead = 0; error2 > 0; look_ahead++)
                 error2 >>= 2;
@@ -429,8 +666,8 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
          * Now calculate the error in (1 << look_ahead) ticks, but first
          * remove the single look ahead already included in the error.
          */
-        tick_error = tick_length >> (NTP_SCALE_SHIFT - clock->shift + 1);
-        tick_error -= clock->xtime_interval >> 1;
+        tick_error = tick_length >> (timekeeper.ntp_error_shift + 1);
+        tick_error -= timekeeper.xtime_interval >> 1;
         error = ((error - tick_error) >> look_ahead) + tick_error;
 
         /* Finally calculate the adjustment shift value.  */
@@ -455,18 +692,18 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
  * this is optimized for the most common adjustments of -1,0,1,
  * for other values we can do a bit more work.
  */
-static void clocksource_adjust(s64 offset)
+static void timekeeping_adjust(s64 offset)
 {
-        s64 error, interval = clock->cycle_interval;
+        s64 error, interval = timekeeper.cycle_interval;
         int adj;
 
-        error = clock->error >> (NTP_SCALE_SHIFT - clock->shift - 1);
+        error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1);
         if (error > interval) {
                 error >>= 2;
                 if (likely(error <= interval))
                         adj = 1;
                 else
-                        adj = clocksource_bigadjust(error, &interval, &offset);
+                        adj = timekeeping_bigadjust(error, &interval, &offset);
         } else if (error < -interval) {
                 error >>= 2;
                 if (likely(error >= -interval)) {
@@ -474,15 +711,15 @@ static void clocksource_adjust(s64 offset)
                         interval = -interval;
                         offset = -offset;
                 } else
-                        adj = clocksource_bigadjust(error, &interval, &offset);
+                        adj = timekeeping_bigadjust(error, &interval, &offset);
         } else
                 return;
 
-        clock->mult += adj;
-        clock->xtime_interval += interval;
-        clock->xtime_nsec -= offset;
-        clock->error -= (interval - offset) <<
-                        (NTP_SCALE_SHIFT - clock->shift);
+        timekeeper.mult += adj;
+        timekeeper.xtime_interval += interval;
+        timekeeper.xtime_nsec -= offset;
+        timekeeper.ntp_error -= (interval - offset) <<
+                                timekeeper.ntp_error_shift;
 }
 
 /**
@@ -492,53 +729,59 @@ static void clocksource_adjust(s64 offset)
  */
 void update_wall_time(void)
 {
+        struct clocksource *clock;
         cycle_t offset;
+        u64 nsecs;
 
         /* Make sure we're fully resumed: */
         if (unlikely(timekeeping_suspended))
                 return;
 
+        clock = timekeeper.clock;
 #ifdef CONFIG_GENERIC_TIME
-        offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
+        offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #else
-        offset = clock->cycle_interval;
+        offset = timekeeper.cycle_interval;
 #endif
-        clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift;
+        timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
 
         /* normally this loop will run just once, however in the
          * case of lost or late ticks, it will accumulate correctly.
          */
-        while (offset >= clock->cycle_interval) {
+        while (offset >= timekeeper.cycle_interval) {
+                u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
+
                 /* accumulate one interval */
-                offset -= clock->cycle_interval;
-                clock->cycle_last += clock->cycle_interval;
+                offset -= timekeeper.cycle_interval;
+                clock->cycle_last += timekeeper.cycle_interval;
 
-                clock->xtime_nsec += clock->xtime_interval;
-                if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) {
-                        clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift;
+                timekeeper.xtime_nsec += timekeeper.xtime_interval;
+                if (timekeeper.xtime_nsec >= nsecps) {
+                        timekeeper.xtime_nsec -= nsecps;
                         xtime.tv_sec++;
                         second_overflow();
                 }
 
-                clock->raw_time.tv_nsec += clock->raw_interval;
-                if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) {
-                        clock->raw_time.tv_nsec -= NSEC_PER_SEC;
-                        clock->raw_time.tv_sec++;
+                raw_time.tv_nsec += timekeeper.raw_interval;
+                if (raw_time.tv_nsec >= NSEC_PER_SEC) {
+                        raw_time.tv_nsec -= NSEC_PER_SEC;
+                        raw_time.tv_sec++;
                 }
 
                 /* accumulate error between NTP and clock interval */
-                clock->error += tick_length;
-                clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift);
+                timekeeper.ntp_error += tick_length;
+                timekeeper.ntp_error -= timekeeper.xtime_interval <<
+                                        timekeeper.ntp_error_shift;
         }
 
         /* correct the clock when NTP error is too big */
-        clocksource_adjust(offset);
+        timekeeping_adjust(offset);
 
         /*
          * Since in the loop above, we accumulate any amount of time
          * in xtime_nsec over a second into xtime.tv_sec, its possible for
          * xtime_nsec to be fairly small after the loop. Further, if we're
-         * slightly speeding the clocksource up in clocksource_adjust(),
+         * slightly speeding the clocksource up in timekeeping_adjust(),
          * its possible the required corrective factor to xtime_nsec could
          * cause it to underflow.
          *
@@ -550,24 +793,25 @@ void update_wall_time(void)
          * We'll correct this error next time through this function, when
          * xtime_nsec is not as small.
          */
-        if (unlikely((s64)clock->xtime_nsec < 0)) {
-                s64 neg = -(s64)clock->xtime_nsec;
-                clock->xtime_nsec = 0;
-                clock->error += neg << (NTP_SCALE_SHIFT - clock->shift);
+        if (unlikely((s64)timekeeper.xtime_nsec < 0)) {
+                s64 neg = -(s64)timekeeper.xtime_nsec;
+                timekeeper.xtime_nsec = 0;
+                timekeeper.ntp_error += neg << timekeeper.ntp_error_shift;
         }
 
         /* store full nanoseconds into xtime after rounding it up and
          * add the remainder to the error difference.
          */
-        xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1;
-        clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
-        clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift);
+        xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1;
+        timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift;
+        timekeeper.ntp_error += timekeeper.xtime_nsec <<
+                                timekeeper.ntp_error_shift;
 
-        update_xtime_cache(cyc2ns(clock, offset));
+        nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift);
+        update_xtime_cache(nsecs);
 
         /* check to see if there is a new clocksource to use */
-        change_clocksource();
-        update_vsyscall(&xtime, clock);
+        update_vsyscall(&xtime, timekeeper.clock);
 }
 
 /**
@@ -583,9 +827,12 @@ void update_wall_time(void)
  */
 void getboottime(struct timespec *ts)
 {
-        set_normalized_timespec(ts,
-                - (wall_to_monotonic.tv_sec + total_sleep_time),
-                - wall_to_monotonic.tv_nsec);
+        struct timespec boottime = {
+                .tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec,
+                .tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec
+        };
+
+        set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
 }
 
 /**
@@ -594,7 +841,7 @@ void getboottime(struct timespec *ts)
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-        ts->tv_sec += total_sleep_time;
+        *ts = timespec_add_safe(*ts, total_sleep_time);
 }
 
 unsigned long get_seconds(void)
@@ -603,6 +850,10 @@ unsigned long get_seconds(void)
 }
 EXPORT_SYMBOL(get_seconds);
 
+struct timespec __current_kernel_time(void)
+{
+        return xtime_cache;
+}
 
 struct timespec current_kernel_time(void)
 {
@@ -618,3 +869,20 @@ struct timespec current_kernel_time(void)
         return now;
 }
 EXPORT_SYMBOL(current_kernel_time);
+
+struct timespec get_monotonic_coarse(void)
+{
+        struct timespec now, mono;
+        unsigned long seq;
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+
+                now = xtime_cache;
+                mono = wall_to_monotonic;
+        } while (read_seqretry(&xtime_lock, seq));
+
+        set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
+                                now.tv_nsec + mono.tv_nsec);
+        return now;
+}
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index fddd69d16e03..1b5b7aa2fdfd 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -275,7 +275,7 @@ static int timer_list_open(struct inode *inode, struct file *filp)
         return single_open(filp, timer_list_show, NULL);
 }
 
-static struct file_operations timer_list_fops = {
+static const struct file_operations timer_list_fops = {
         .open           = timer_list_open,
         .read           = seq_read,
         .llseek         = seq_lseek,
diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
index 4cde8b9c716f..ee5681f8d7ec 100644
--- a/kernel/time/timer_stats.c
+++ b/kernel/time/timer_stats.c
@@ -395,7 +395,7 @@ static int tstats_open(struct inode *inode, struct file *filp)
         return single_open(filp, tstats_show, NULL);
 }
 
-static struct file_operations tstats_fops = {
+static const struct file_operations tstats_fops = {
         .open           = tstats_open,
         .read           = seq_read,
         .write          = tstats_write,
diff --git a/kernel/timer.c b/kernel/timer.c
index a3d25f415019..5db5a8d26811 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -37,7 +37,7 @@
 #include <linux/delay.h>
 #include <linux/tick.h>
 #include <linux/kallsyms.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <linux/sched.h>
 
 #include <asm/uaccess.h>
@@ -46,6 +46,9 @@
 #include <asm/timex.h>
 #include <asm/io.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/timer.h>
+
 u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
 
 EXPORT_SYMBOL(jiffies_64);
@@ -72,6 +75,7 @@ struct tvec_base {
         spinlock_t lock;
         struct timer_list *running_timer;
         unsigned long timer_jiffies;
+        unsigned long next_timer;
         struct tvec_root tv1;
         struct tvec tv2;
         struct tvec tv3;
@@ -520,6 +524,25 @@ static inline void debug_timer_activate(struct timer_list *timer) { }
 static inline void debug_timer_deactivate(struct timer_list *timer) { }
 #endif
 
+static inline void debug_init(struct timer_list *timer)
+{
+        debug_timer_init(timer);
+        trace_timer_init(timer);
+}
+
+static inline void
+debug_activate(struct timer_list *timer, unsigned long expires)
+{
+        debug_timer_activate(timer);
+        trace_timer_start(timer, expires);
+}
+
+static inline void debug_deactivate(struct timer_list *timer)
+{
+        debug_timer_deactivate(timer);
+        trace_timer_cancel(timer);
+}
+
 static void __init_timer(struct timer_list *timer,
                          const char *name,
                          struct lock_class_key *key)
@@ -548,7 +571,7 @@ void init_timer_key(struct timer_list *timer,
                     const char *name,
                     struct lock_class_key *key)
 {
-        debug_timer_init(timer);
+        debug_init(timer);
         __init_timer(timer, name, key);
 }
 EXPORT_SYMBOL(init_timer_key);
@@ -567,7 +590,7 @@ static inline void detach_timer(struct timer_list *timer,
 {
         struct list_head *entry = &timer->entry;
 
-        debug_timer_deactivate(timer);
+        debug_deactivate(timer);
 
         __list_del(entry->prev, entry->next);
         if (clear_pending)
@@ -622,13 +645,16 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 
         if (timer_pending(timer)) {
                 detach_timer(timer, 0);
+                if (timer->expires == base->next_timer &&
+                    !tbase_get_deferrable(timer->base))
+                        base->next_timer = base->timer_jiffies;
                 ret = 1;
         } else {
                 if (pending_only)
                         goto out_unlock;
         }
 
-        debug_timer_activate(timer);
+        debug_activate(timer, expires);
 
         new_base = __get_cpu_var(tvec_bases);
 
@@ -663,6 +689,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
         }
 
         timer->expires = expires;
+        if (time_before(timer->expires, base->next_timer) &&
+            !tbase_get_deferrable(timer->base))
+                base->next_timer = timer->expires;
         internal_add_timer(base, timer);
 
 out_unlock:
@@ -780,7 +809,10 @@ void add_timer_on(struct timer_list *timer, int cpu)
         BUG_ON(timer_pending(timer) || !timer->function);
         spin_lock_irqsave(&base->lock, flags);
         timer_set_base(timer, base);
-        debug_timer_activate(timer);
+        debug_activate(timer, timer->expires);
+        if (time_before(timer->expires, base->next_timer) &&
+            !tbase_get_deferrable(timer->base))
+                base->next_timer = timer->expires;
         internal_add_timer(base, timer);
         /*
          * Check whether the other CPU is idle and needs to be
@@ -817,6 +849,9 @@ int del_timer(struct timer_list *timer)
                 base = lock_timer_base(timer, &flags);
                 if (timer_pending(timer)) {
                         detach_timer(timer, 1);
+                        if (timer->expires == base->next_timer &&
+                            !tbase_get_deferrable(timer->base))
+                                base->next_timer = base->timer_jiffies;
                         ret = 1;
                 }
                 spin_unlock_irqrestore(&base->lock, flags);
@@ -850,6 +885,9 @@ int try_to_del_timer_sync(struct timer_list *timer)
         ret = 0;
         if (timer_pending(timer)) {
                 detach_timer(timer, 1);
+                if (timer->expires == base->next_timer &&
+                    !tbase_get_deferrable(timer->base))
+                        base->next_timer = base->timer_jiffies;
                 ret = 1;
         }
 out:
@@ -984,7 +1022,9 @@ static inline void __run_timers(struct tvec_base *base)
                                  */
                                 lock_map_acquire(&lockdep_map);
 
+                                trace_timer_expire_entry(timer);
                                 fn(data);
+                                trace_timer_expire_exit(timer);
 
                                 lock_map_release(&lockdep_map);
 
@@ -1007,8 +1047,8 @@ static inline void __run_timers(struct tvec_base *base)
 #ifdef CONFIG_NO_HZ
 /*
  * Find out when the next timer event is due to happen. This
- * is used on S/390 to stop all activity when a cpus is idle.
- * This functions needs to be called disabled.
+ * is used on S/390 to stop all activity when a CPU is idle.
+ * This function needs to be called with interrupts disabled.
  */
 static unsigned long __next_timer_interrupt(struct tvec_base *base)
 {
@@ -1134,7 +1174,9 @@ unsigned long get_next_timer_interrupt(unsigned long now)
         unsigned long expires;
 
         spin_lock(&base->lock);
-        expires = __next_timer_interrupt(base);
+        if (time_before_eq(base->next_timer, base->timer_jiffies))
+                base->next_timer = __next_timer_interrupt(base);
+        expires = base->next_timer;
         spin_unlock(&base->lock);
 
         if (time_before_eq(expires, now))
@@ -1169,7 +1211,7 @@ static void run_timer_softirq(struct softirq_action *h)
 {
         struct tvec_base *base = __get_cpu_var(tvec_bases);
 
-        perf_counter_do_pending();
+        perf_event_do_pending();
 
         hrtimer_run_pending();
 
@@ -1522,6 +1564,7 @@ static int __cpuinit init_timers_cpu(int cpu)
                 INIT_LIST_HEAD(base->tv1.vec + j);
 
         base->timer_jiffies = jiffies;
+        base->next_timer = base->timer_jiffies;
         return 0;
 }
 
@@ -1534,6 +1577,9 @@ static void migrate_timer_list(struct tvec_base *new_base, struct list_head *hea
                 timer = list_first_entry(head, struct timer_list, entry);
                 detach_timer(timer, 0);
                 timer_set_base(timer, new_base);
+                if (time_before(timer->expires, new_base->next_timer) &&
+                    !tbase_get_deferrable(timer->base))
+                        new_base->next_timer = timer->expires;
                 internal_add_timer(new_base, timer);
         }
 }
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index e71634604400..b416512ad17f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -83,7 +83,7 @@ config RING_BUFFER_ALLOW_SWAP
 # This allows those options to appear when no other tracer is selected. But the
 # options do not appear when something else selects it. We need the two options
 # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
-# hidding of the automatic options options.
+# hidding of the automatic options.
 
 config TRACING
         bool
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 844164dca90a..26f03ac07c2b 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -42,7 +42,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
 obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
 obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
-obj-$(CONFIG_POWER_TRACER) += trace_power.o
 obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
 obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
 obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
@@ -54,5 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o
 obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
 obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
+obj-$(CONFIG_EVENT_TRACING) += power-traces.o
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 3eb159c277c8..d9d6206e0b14 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -856,6 +856,37 @@ static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 }
 
 /**
+ * blk_add_trace_rq_remap - Add a trace for a request-remap operation
+ * @q:          queue the io is for
+ * @rq:         the source request
+ * @dev:        target device
+ * @from:       source sector
+ *
+ * Description:
+ *     Device mapper remaps request to other devices.
+ *     Add a trace for that action.
+ *
+ **/
+static void blk_add_trace_rq_remap(struct request_queue *q,
+                                   struct request *rq, dev_t dev,
+                                   sector_t from)
+{
+        struct blk_trace *bt = q->blk_trace;
+        struct blk_io_trace_remap r;
+
+        if (likely(!bt))
+                return;
+
+        r.device_from = cpu_to_be32(dev);
+        r.device_to   = cpu_to_be32(disk_devt(rq->rq_disk));
+        r.sector_from = cpu_to_be64(from);
+
+        __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
+                        rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
+                        sizeof(r), &r);
+}
+
+/**
  * blk_add_driver_data - Add binary message with driver-specific data
  * @q:          queue the io is for
  * @rq:         io request
@@ -922,10 +953,13 @@ static void blk_register_tracepoints(void)
         WARN_ON(ret);
         ret = register_trace_block_remap(blk_add_trace_remap);
         WARN_ON(ret);
+        ret = register_trace_block_rq_remap(blk_add_trace_rq_remap);
+        WARN_ON(ret);
 }
 
 static void blk_unregister_tracepoints(void)
 {
+        unregister_trace_block_rq_remap(blk_add_trace_rq_remap);
         unregister_trace_block_remap(blk_add_trace_remap);
         unregister_trace_block_split(blk_add_trace_split);
         unregister_trace_block_unplug_io(blk_add_trace_unplug_io);
@@ -1657,6 +1691,11 @@ int blk_trace_init_sysfs(struct device *dev)
         return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
 }
 
+void blk_trace_remove_sysfs(struct device *dev)
+{
+        sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
+}
+
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 
 #ifdef CONFIG_EVENT_TRACING
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index cc615f84751b..37ba67e33265 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -225,7 +225,11 @@ static void ftrace_update_pid_func(void)
         if (ftrace_trace_function == ftrace_stub)
                 return;
 
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
         func = ftrace_trace_function;
+#else
+        func = __ftrace_trace_function;
+#endif
 
         if (ftrace_pid_trace) {
                 set_ftrace_pid_function(func);
@@ -1074,14 +1078,9 @@ static void ftrace_replace_code(int enable)
                 failed = __ftrace_replace_code(rec, enable);
                 if (failed) {
                         rec->flags |= FTRACE_FL_FAILED;
-                        if ((system_state == SYSTEM_BOOTING) ||
-                            !core_kernel_text(rec->ip)) {
-                                ftrace_free_rec(rec);
-                                } else {
-                                ftrace_bug(failed, rec->ip);
-                                        /* Stop processing */
-                                        return;
-                                }
+                        ftrace_bug(failed, rec->ip);
+                        /* Stop processing */
+                        return;
                 }
         } while_for_each_ftrace_rec();
 }
@@ -1520,7 +1519,7 @@ static int t_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations show_ftrace_seq_ops = {
+static const struct seq_operations show_ftrace_seq_ops = {
         .start = t_start,
         .next = t_next,
         .stop = t_stop,
@@ -1621,8 +1620,10 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
                 if (!ret) {
                         struct seq_file *m = file->private_data;
                         m->private = iter;
-                } else
+                } else {
+                        trace_parser_put(&iter->parser);
                         kfree(iter);
+                }
         } else
                 file->private_data = iter;
         mutex_unlock(&ftrace_regex_lock);
@@ -2202,7 +2203,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
         struct trace_parser *parser;
         ssize_t ret, read;
 
-        if (!cnt || cnt < 0)
+        if (!cnt)
                 return 0;
 
         mutex_lock(&ftrace_regex_lock);
@@ -2216,7 +2217,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
         parser = &iter->parser;
         read = trace_get_user(parser, ubuf, cnt, ppos);
 
-        if (trace_parser_loaded(parser) &&
+        if (read >= 0 && trace_parser_loaded(parser) &&
             !trace_parser_cont(parser)) {
                 ret = ftrace_process_regex(parser->buffer,
                                            parser->idx, enable);
@@ -2414,11 +2415,9 @@ unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
 static void *
 __g_next(struct seq_file *m, loff_t *pos)
 {
-        unsigned long *array = m->private;
-
         if (*pos >= ftrace_graph_count)
                 return NULL;
-        return &array[*pos];
+        return &ftrace_graph_funcs[*pos];
 }
 
 static void *
@@ -2461,7 +2460,7 @@ static int g_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations ftrace_graph_seq_ops = {
+static const struct seq_operations ftrace_graph_seq_ops = {
         .start = g_start,
         .next = g_next,
         .stop = g_stop,
@@ -2482,16 +2481,10 @@ ftrace_graph_open(struct inode *inode, struct file *file)
                 ftrace_graph_count = 0;
                 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
         }
+        mutex_unlock(&graph_lock);
 
-        if (file->f_mode & FMODE_READ) {
+        if (file->f_mode & FMODE_READ)
                 ret = seq_open(file, &ftrace_graph_seq_ops);
-                if (!ret) {
-                        struct seq_file *m = file->private_data;
-                        m->private = ftrace_graph_funcs;
-                }
-        } else
-                file->private_data = ftrace_graph_funcs;
-        mutex_unlock(&graph_lock);
 
         return ret;
 }
@@ -2560,9 +2553,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
                    size_t cnt, loff_t *ppos)
 {
         struct trace_parser parser;
-        unsigned long *array;
-        size_t read = 0;
-        ssize_t ret;
+        ssize_t read, ret;
 
         if (!cnt || cnt < 0)
                 return 0;
@@ -2571,35 +2562,31 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 
         if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
                 ret = -EBUSY;
-                goto out;
+                goto out_unlock;
         }
 
-        if (file->f_mode & FMODE_READ) {
-                struct seq_file *m = file->private_data;
-                array = m->private;
-        } else
-                array = file->private_data;
-
         if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
                 ret = -ENOMEM;
-                goto out;
+                goto out_unlock;
         }
 
         read = trace_get_user(&parser, ubuf, cnt, ppos);
 
-        if (trace_parser_loaded((&parser))) {
+        if (read >= 0 && trace_parser_loaded((&parser))) {
                 parser.buffer[parser.idx] = 0;
 
                 /* we allow only one expression at a time */
-                ret = ftrace_set_func(array, &ftrace_graph_count,
+                ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
                                         parser.buffer);
                 if (ret)
-                        goto out;
+                        goto out_free;
         }
 
         ret = read;
- out:
+
+out_free:
         trace_parser_put(&parser);
+out_unlock:
         mutex_unlock(&graph_lock);
 
         return ret;
@@ -2670,19 +2657,17 @@ static int ftrace_convert_nops(struct module *mod,
 }
 
 #ifdef CONFIG_MODULES
-void ftrace_release(void *start, void *end)
+void ftrace_release_mod(struct module *mod)
 {
         struct dyn_ftrace *rec;
         struct ftrace_page *pg;
-        unsigned long s = (unsigned long)start;
-        unsigned long e = (unsigned long)end;
 
-        if (ftrace_disabled || !start || start == end)
+        if (ftrace_disabled)
                 return;
 
         mutex_lock(&ftrace_lock);
         do_for_each_ftrace_rec(pg, rec) {
-                if ((rec->ip >= s) && (rec->ip < e)) {
+                if (within_module_core(rec->ip, mod)) {
                         /*
                          * rec->ip is changed in ftrace_free_rec()
                          * It should not between s and e if record was freed.
@@ -2714,9 +2699,7 @@ static int ftrace_module_notify(struct notifier_block *self,
                                    mod->num_ftrace_callsites);
                 break;
         case MODULE_STATE_GOING:
-                ftrace_release(mod->ftrace_callsites,
-                               mod->ftrace_callsites +
-                               mod->num_ftrace_callsites);
+                ftrace_release_mod(mod);
                 break;
         }
 
@@ -3030,7 +3013,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 
 int
 ftrace_enable_sysctl(struct ctl_table *table, int write,
-                     struct file *file, void __user *buffer, size_t *lenp,
+                     void __user *buffer, size_t *lenp,
                      loff_t *ppos)
 {
         int ret;
@@ -3040,7 +3023,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
         mutex_lock(&ftrace_lock);
 
-        ret  = proc_dointvec(table, write, file, buffer, lenp, ppos);
+        ret  = proc_dointvec(table, write, buffer, lenp, ppos);
 
         if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
                 goto out;
diff --git a/kernel/trace/kmemtrace.c b/kernel/trace/kmemtrace.c
index 81b1645c8549..a91da69f153a 100644
--- a/kernel/trace/kmemtrace.c
+++ b/kernel/trace/kmemtrace.c
@@ -501,7 +501,7 @@ static int __init init_kmem_tracer(void)
                 return 1;
         }
 
-        if (!register_tracer(&kmem_tracer)) {
+        if (register_tracer(&kmem_tracer) != 0) {
                 pr_warning("Warning: could not register the kmem tracer\n");
                 return 1;
         }
diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
new file mode 100644
index 000000000000..e06c6e3d56a3
--- /dev/null
+++ b/kernel/trace/power-traces.c
@@ -0,0 +1,20 @@
+/*
+ * Power trace points
+ *
+ * Copyright (C) 2009 Arjan van de Ven <arjan@linux.intel.com>
+ */
+
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/power.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_start);
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_end);
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_frequency);
+
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 6eef38923b07..d4ff01970547 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -201,8 +201,6 @@ int tracing_is_on(void)
 }
 EXPORT_SYMBOL_GPL(tracing_is_on);
 
-#include "trace.h"
-
 #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array))
 #define RB_ALIGNMENT            4U
 #define RB_MAX_SMALL_DATA       (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 420232a1fbba..c820b0310a12 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -125,13 +125,13 @@ int ftrace_dump_on_oops;
 
 static int tracing_set_tracer(const char *buf);
 
-#define BOOTUP_TRACER_SIZE              100
-static char bootup_tracer_buf[BOOTUP_TRACER_SIZE] __initdata;
+#define MAX_TRACER_SIZE         100
+static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
 static int __init set_ftrace(char *str)
 {
-        strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE);
+        strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
         default_bootup_tracer = bootup_tracer_buf;
         /* We are using ftrace early, expand it */
         ring_buffer_expanded = 1;
@@ -242,13 +242,6 @@ static struct tracer		*trace_types __read_mostly;
 static struct tracer            *current_trace __read_mostly;
 
 /*
- * max_tracer_type_len is used to simplify the allocating of
- * buffers to read userspace tracer names. We keep track of
- * the longest tracer name registered.
- */
-static int                      max_tracer_type_len;
-
-/*
  * trace_types_lock is used to protect the trace_types list.
  * This lock is also used to keep user access serialized.
  * Accesses from userspace will grab this lock while userspace
@@ -422,7 +415,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 
         /* read the non-space input */
         while (cnt && !isspace(ch)) {
-                if (parser->idx < parser->size)
+                if (parser->idx < parser->size - 1)
                         parser->buffer[parser->idx++] = ch;
                 else {
                         ret = -EINVAL;
@@ -625,7 +618,6 @@ __releases(kernel_lock)
 __acquires(kernel_lock)
 {
         struct tracer *t;
-        int len;
         int ret = 0;
 
         if (!type->name) {
@@ -633,6 +625,11 @@ __acquires(kernel_lock)
                 return -1;
         }
 
+        if (strlen(type->name) > MAX_TRACER_SIZE) {
+                pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
+                return -1;
+        }
+
         /*
          * When this gets called we hold the BKL which means that
          * preemption is disabled. Various trace selftests however
@@ -647,7 +644,7 @@ __acquires(kernel_lock)
         for (t = trace_types; t; t = t->next) {
                 if (strcmp(type->name, t->name) == 0) {
                         /* already found */
-                        pr_info("Trace %s already registered\n",
+                        pr_info("Tracer %s already registered\n",
                                 type->name);
                         ret = -1;
                         goto out;
@@ -698,9 +695,6 @@ __acquires(kernel_lock)
 
         type->next = trace_types;
         trace_types = type;
-        len = strlen(type->name);
-        if (len > max_tracer_type_len)
-                max_tracer_type_len = len;
 
  out:
         tracing_selftest_running = false;
@@ -709,7 +703,7 @@ __acquires(kernel_lock)
         if (ret || !default_bootup_tracer)
                 goto out_unlock;
 
-        if (strncmp(default_bootup_tracer, type->name, BOOTUP_TRACER_SIZE))
+        if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
                 goto out_unlock;
 
         printk(KERN_INFO "Starting tracer '%s'\n", type->name);
@@ -731,14 +725,13 @@ __acquires(kernel_lock)
 void unregister_tracer(struct tracer *type)
 {
         struct tracer **t;
-        int len;
 
         mutex_lock(&trace_types_lock);
         for (t = &trace_types; *t; t = &(*t)->next) {
                 if (*t == type)
                         goto found;
         }
-        pr_info("Trace %s not registered\n", type->name);
+        pr_info("Tracer %s not registered\n", type->name);
         goto out;
 
  found:
@@ -751,17 +744,7 @@ void unregister_tracer(struct tracer *type)
                         current_trace->stop(&global_trace);
                 current_trace = &nop_trace;
         }
-
-        if (strlen(type->name) != max_tracer_type_len)
-                goto out;
-
-        max_tracer_type_len = 0;
-        for (t = &trace_types; *t; t = &(*t)->next) {
-                len = strlen((*t)->name);
-                if (len > max_tracer_type_len)
-                        max_tracer_type_len = len;
-        }
- out:
+out:
         mutex_unlock(&trace_types_lock);
 }
 
@@ -1410,7 +1393,7 @@ int trace_array_vprintk(struct trace_array *tr,
 
 int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
-        return trace_array_printk(&global_trace, ip, fmt, args);
+        return trace_array_vprintk(&global_trace, ip, fmt, args);
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
@@ -1966,7 +1949,7 @@ static int s_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations tracer_seq_ops = {
+static const struct seq_operations tracer_seq_ops = {
         .start          = s_start,
         .next           = s_next,
         .stop           = s_stop,
@@ -2001,11 +1984,9 @@ __tracing_open(struct inode *inode, struct file *file)
         if (current_trace)
                 *iter->trace = *current_trace;
 
-        if (!alloc_cpumask_var(&iter->started, GFP_KERNEL))
+        if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
                 goto fail;
 
-        cpumask_clear(iter->started);
-
         if (current_trace && current_trace->print_max)
                 iter->tr = &max_tr;
         else
@@ -2180,7 +2161,7 @@ static int t_show(struct seq_file *m, void *v)
         return 0;
 }
 
-static struct seq_operations show_traces_seq_ops = {
+static const struct seq_operations show_traces_seq_ops = {
         .start          = t_start,
         .next           = t_next,
         .stop           = t_stop,
@@ -2610,7 +2591,7 @@ static ssize_t
 tracing_set_trace_read(struct file *filp, char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
-        char buf[max_tracer_type_len+2];
+        char buf[MAX_TRACER_SIZE+2];
         int r;
 
         mutex_lock(&trace_types_lock);
@@ -2760,15 +2741,15 @@ static ssize_t
 tracing_set_trace_write(struct file *filp, const char __user *ubuf,
                         size_t cnt, loff_t *ppos)
 {
-        char buf[max_tracer_type_len+1];
+        char buf[MAX_TRACER_SIZE+1];
         int i;
         size_t ret;
         int err;
 
         ret = cnt;
 
-        if (cnt > max_tracer_type_len)
-                cnt = max_tracer_type_len;
+        if (cnt > MAX_TRACER_SIZE)
+                cnt = MAX_TRACER_SIZE;
 
         if (copy_from_user(&buf, ubuf, cnt))
                 return -EFAULT;
@@ -4406,7 +4387,7 @@ __init static int tracer_alloc_buffers(void)
         if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
                 goto out_free_buffer_mask;
 
-        if (!alloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL))
+        if (!zalloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL))
                 goto out_free_tracing_cpumask;
 
         /* To save memory, keep the ring buffer size to its minimum */
@@ -4417,7 +4398,6 @@ __init static int tracer_alloc_buffers(void)
 
         cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
         cpumask_copy(tracing_cpumask, cpu_all_mask);
-        cpumask_clear(tracing_reader_cpumask);
 
         /* TODO: make the number of buffers hot pluggable with CPUS */
         global_trace.buffer = ring_buffer_alloc(ring_buf_size,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 86bcff94791a..405cb850b75d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -11,7 +11,6 @@
 #include <linux/ftrace.h>
 #include <trace/boot.h>
 #include <linux/kmemtrace.h>
-#include <trace/power.h>
 
 #include <linux/trace_seq.h>
 #include <linux/ftrace_event.h>
@@ -37,7 +36,6 @@ enum trace_type {
         TRACE_HW_BRANCHES,
         TRACE_KMEM_ALLOC,
         TRACE_KMEM_FREE,
-        TRACE_POWER,
         TRACE_BLK,
 
         __TRACE_LAST_TYPE,
@@ -207,7 +205,6 @@ extern void __ftrace_bad_type(void);
                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
                           TRACE_GRAPH_RET);             \
                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
-                IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
                           TRACE_KMEM_ALLOC);    \
                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 7a7a9fd249a9..4a194f08f88c 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -34,6 +34,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
         struct trace_array *tr = branch_tracer;
         struct ring_buffer_event *event;
         struct trace_branch *entry;
+        struct ring_buffer *buffer;
         unsigned long flags;
         int cpu, pc;
         const char *p;
@@ -54,7 +55,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
                 goto out;
 
         pc = preempt_count();
-        event = trace_buffer_lock_reserve(tr, TRACE_BRANCH,
+        buffer = tr->buffer;
+        event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH,
                                           sizeof(*entry), flags, pc);
         if (!event)
                 goto out;
@@ -74,8 +76,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
         entry->line = f->line;
         entry->correct = val == expect;
 
-        if (!filter_check_discard(call, entry, tr->buffer, event))
-                ring_buffer_unlock_commit(tr->buffer, event);
+        if (!filter_check_discard(call, entry, buffer, event))
+                ring_buffer_unlock_commit(buffer, event);
 
  out:
         atomic_dec(&tr->data[cpu]->disabled);
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index a431748ddd6e..ead3d724599d 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -330,23 +330,6 @@ FTRACE_ENTRY(hw_branch, hw_branch_entry,
         F_printk("from: %llx to: %llx", __entry->from, __entry->to)
 );
 
-FTRACE_ENTRY(power, trace_power,
-
-        TRACE_POWER,
-
-        F_STRUCT(
-                __field_struct( struct power_trace,     state_data      )
-                __field_desc(   s64,    state_data,     stamp           )
-                __field_desc(   s64,    state_data,     end             )
-                __field_desc(   int,    state_data,     type            )
-                __field_desc(   int,    state_data,     state           )
-        ),
-
-        F_printk("%llx->%llx type:%u state:%u",
-                 __entry->stamp, __entry->end,
-                 __entry->type, __entry->state)
-);
-
 FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry,
 
         TRACE_KMEM_ALLOC,
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 55a25c933d15..8d5c171cc998 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -8,6 +8,62 @@
 #include <linux/module.h>
 #include "trace.h"
 
+/*
+ * We can't use a size but a type in alloc_percpu()
+ * So let's create a dummy type that matches the desired size
+ */
+typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t;
+
+char            *trace_profile_buf;
+EXPORT_SYMBOL_GPL(trace_profile_buf);
+
+char            *trace_profile_buf_nmi;
+EXPORT_SYMBOL_GPL(trace_profile_buf_nmi);
+
+/* Count the events in use (per event id, not per instance) */
+static int      total_profile_count;
+
+static int ftrace_profile_enable_event(struct ftrace_event_call *event)
+{
+        char *buf;
+        int ret = -ENOMEM;
+
+        if (atomic_inc_return(&event->profile_count))
+                return 0;
+
+        if (!total_profile_count) {
+                buf = (char *)alloc_percpu(profile_buf_t);
+                if (!buf)
+                        goto fail_buf;
+
+                rcu_assign_pointer(trace_profile_buf, buf);
+
+                buf = (char *)alloc_percpu(profile_buf_t);
+                if (!buf)
+                        goto fail_buf_nmi;
+
+                rcu_assign_pointer(trace_profile_buf_nmi, buf);
+        }
+
+        ret = event->profile_enable();
+        if (!ret) {
+                total_profile_count++;
+                return 0;
+        }
+
+fail_buf_nmi:
+        if (!total_profile_count) {
+                free_percpu(trace_profile_buf_nmi);
+                free_percpu(trace_profile_buf);
+                trace_profile_buf_nmi = NULL;
+                trace_profile_buf = NULL;
+        }
+fail_buf:
+        atomic_dec(&event->profile_count);
+
+        return ret;
+}
+
 int ftrace_profile_enable(int event_id)
 {
         struct ftrace_event_call *event;
@@ -17,7 +73,7 @@ int ftrace_profile_enable(int event_id)
         list_for_each_entry(event, &ftrace_events, list) {
                 if (event->id == event_id && event->profile_enable &&
                     try_module_get(event->mod)) {
-                        ret = event->profile_enable(event);
+                        ret = ftrace_profile_enable_event(event);
                         break;
                 }
         }
@@ -26,6 +82,33 @@ int ftrace_profile_enable(int event_id)
         return ret;
 }
 
+static void ftrace_profile_disable_event(struct ftrace_event_call *event)
+{
+        char *buf, *nmi_buf;
+
+        if (!atomic_add_negative(-1, &event->profile_count))
+                return;
+
+        event->profile_disable();
+
+        if (!--total_profile_count) {
+                buf = trace_profile_buf;
+                rcu_assign_pointer(trace_profile_buf, NULL);
+
+                nmi_buf = trace_profile_buf_nmi;
+                rcu_assign_pointer(trace_profile_buf_nmi, NULL);
+
+                /*
+                 * Ensure every events in profiling have finished before
+                 * releasing the buffers
+                 */
+                synchronize_sched();
+
+                free_percpu(buf);
+                free_percpu(nmi_buf);
+        }
+}
+
 void ftrace_profile_disable(int event_id)
 {
         struct ftrace_event_call *event;
@@ -33,7 +116,7 @@ void ftrace_profile_disable(int event_id)
         mutex_lock(&event_mutex);
         list_for_each_entry(event, &ftrace_events, list) {
                 if (event->id == event_id) {
-                        event->profile_disable(event);
+                        ftrace_profile_disable_event(event);
                         module_put(event->mod);
                         break;
                 }
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 56c260b83a9c..d128f65778e6 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -232,10 +232,9 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
                    size_t cnt, loff_t *ppos)
 {
         struct trace_parser parser;
-        size_t read = 0;
-        ssize_t ret;
+        ssize_t read, ret;
 
-        if (!cnt || cnt < 0)
+        if (!cnt)
                 return 0;
 
         ret = tracing_update_buffers();
@@ -247,7 +246,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 
         read = trace_get_user(&parser, ubuf, cnt, ppos);
 
-        if (trace_parser_loaded((&parser))) {
+        if (read >= 0 && trace_parser_loaded((&parser))) {
                 int set = 1;
 
                 if (*parser.buffer == '!')
@@ -271,42 +270,32 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        struct list_head *list = m->private;
-        struct ftrace_event_call *call;
+        struct ftrace_event_call *call = v;
 
         (*pos)++;
 
-        for (;;) {
-                if (list == &ftrace_events)
-                        return NULL;
-
-                call = list_entry(list, struct ftrace_event_call, list);
-
+        list_for_each_entry_continue(call, &ftrace_events, list) {
                 /*
                  * The ftrace subsystem is for showing formats only.
                  * They can not be enabled or disabled via the event files.
                  */
                 if (call->regfunc)
-                        break;
-
-                list = list->next;
+                        return call;
         }
 
-        m->private = list->next;
-
-        return call;
+        return NULL;
 }
 
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
-        struct ftrace_event_call *call = NULL;
+        struct ftrace_event_call *call;
         loff_t l;
 
         mutex_lock(&event_mutex);
 
-        m->private = ftrace_events.next;
+        call = list_entry(&ftrace_events, struct ftrace_event_call, list);
         for (l = 0; l <= *pos; ) {
-                call = t_next(m, NULL, &l);
+                call = t_next(m, call, &l);
                 if (!call)
                         break;
         }
@@ -316,37 +305,28 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 static void *
 s_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        struct list_head *list = m->private;
-        struct ftrace_event_call *call;
+        struct ftrace_event_call *call = v;
 
         (*pos)++;
 
- retry:
-        if (list == &ftrace_events)
-                return NULL;
-
-        call = list_entry(list, struct ftrace_event_call, list);
-
-        if (!call->enabled) {
-                list = list->next;
-                goto retry;
+        list_for_each_entry_continue(call, &ftrace_events, list) {
+                if (call->enabled)
+                        return call;
         }
 
-        m->private = list->next;
-
-        return call;
+        return NULL;
 }
 
 static void *s_start(struct seq_file *m, loff_t *pos)
 {
-        struct ftrace_event_call *call = NULL;
+        struct ftrace_event_call *call;
         loff_t l;
 
         mutex_lock(&event_mutex);
 
-        m->private = ftrace_events.next;
+        call = list_entry(&ftrace_events, struct ftrace_event_call, list);
         for (l = 0; l <= *pos; ) {
-                call = s_next(m, NULL, &l);
+                call = s_next(m, call, &l);
                 if (!call)
                         break;
         }
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 23245785927f..98a6cc5c64ed 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -933,8 +933,9 @@ static void postfix_clear(struct filter_parse_state *ps)
 
         while (!list_empty(&ps->postfix)) {
                 elt = list_first_entry(&ps->postfix, struct postfix_elt, list);
-                kfree(elt->operand);
                 list_del(&elt->list);
+                kfree(elt->operand);
+                kfree(elt);
         }
 }
 
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index ca7d7c4d0c2a..69543a905cd5 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -155,7 +155,7 @@ static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
                     seq_print_ip_sym(seq, it->from, symflags) &&
                     trace_seq_printf(seq, "\n"))
                         return TRACE_TYPE_HANDLED;
-                return TRACE_TYPE_PARTIAL_LINE;;
+                return TRACE_TYPE_PARTIAL_LINE;
         }
         return TRACE_TYPE_UNHANDLED;
 }
@@ -165,6 +165,7 @@ void trace_hw_branch(u64 from, u64 to)
         struct ftrace_event_call *call = &event_hw_branch;
         struct trace_array *tr = hw_branch_trace;
         struct ring_buffer_event *event;
+        struct ring_buffer *buf;
         struct hw_branch_entry *entry;
         unsigned long irq1;
         int cpu;
@@ -180,7 +181,8 @@ void trace_hw_branch(u64 from, u64 to)
         if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
                 goto out;
 
-        event = trace_buffer_lock_reserve(tr, TRACE_HW_BRANCHES,
+        buf = tr->buffer;
+        event = trace_buffer_lock_reserve(buf, TRACE_HW_BRANCHES,
                                           sizeof(*entry), 0, 0);
         if (!event)
                 goto out;
@@ -189,8 +191,8 @@ void trace_hw_branch(u64 from, u64 to)
         entry->ent.type = TRACE_HW_BRANCHES;
         entry->from = from;
         entry->to   = to;
-        if (!filter_check_discard(call, entry, tr->buffer, event))
-                trace_buffer_unlock_commit(tr, event, 0, 0);
+        if (!filter_check_discard(call, entry, buf, event))
+                trace_buffer_unlock_commit(buf, event, 0, 0);
 
  out:
         atomic_dec(&tr->data[cpu]->disabled);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index f572f44c6e1e..ed17565826b0 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -486,16 +486,18 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
                                 hardirq ? 'h' : softirq ? 's' : '.'))
                 return 0;
 
-        if (entry->lock_depth < 0)
-                ret = trace_seq_putc(s, '.');
+        if (entry->preempt_count)
+                ret = trace_seq_printf(s, "%x", entry->preempt_count);
         else
-                ret = trace_seq_printf(s, "%d", entry->lock_depth);
+                ret = trace_seq_putc(s, '.');
+
         if (!ret)
                 return 0;
 
-        if (entry->preempt_count)
-                return trace_seq_printf(s, "%x", entry->preempt_count);
-        return trace_seq_putc(s, '.');
+        if (entry->lock_depth < 0)
+                return trace_seq_putc(s, '.');
+
+        return trace_seq_printf(s, "%d", entry->lock_depth);
 }
 
 static int
@@ -883,7 +885,7 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
         trace_assign_type(field, iter->ent);
 
         if (!S)
-                task_state_char(field->prev_state);
+                S = task_state_char(field->prev_state);
         T = task_state_char(field->next_state);
         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
                               field->prev_pid,
@@ -918,7 +920,7 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
         trace_assign_type(field, iter->ent);
 
         if (!S)
-                task_state_char(field->prev_state);
+                S = task_state_char(field->prev_state);
         T = task_state_char(field->next_state);
 
         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
deleted file mode 100644
index fe1a00f1445a..000000000000
--- a/kernel/trace/trace_power.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * ring buffer based C-state tracer
- *
- * Arjan van de Ven <arjan@linux.intel.com>
- * Copyright (C) 2008 Intel Corporation
- *
- * Much is borrowed from trace_boot.c which is
- * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
- *
- */
-
-#include <linux/init.h>
-#include <linux/debugfs.h>
-#include <trace/power.h>
-#include <linux/kallsyms.h>
-#include <linux/module.h>
-
-#include "trace.h"
-#include "trace_output.h"
-
-static struct trace_array *power_trace;
-static int __read_mostly trace_power_enabled;
-
-static void probe_power_start(struct power_trace *it, unsigned int type,
-                                unsigned int level)
-{
-        if (!trace_power_enabled)
-                return;
-
-        memset(it, 0, sizeof(struct power_trace));
-        it->state = level;
-        it->type = type;
-        it->stamp = ktime_get();
-}
-
-
-static void probe_power_end(struct power_trace *it)
-{
-        struct ftrace_event_call *call = &event_power;
-        struct ring_buffer_event *event;
-        struct ring_buffer *buffer;
-        struct trace_power *entry;
-        struct trace_array_cpu *data;
-        struct trace_array *tr = power_trace;
-
-        if (!trace_power_enabled)
-                return;
-
-        buffer = tr->buffer;
-
-        preempt_disable();
-        it->end = ktime_get();
-        data = tr->data[smp_processor_id()];
-
-        event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
-                                          sizeof(*entry), 0, 0);
-        if (!event)
-                goto out;
-        entry   = ring_buffer_event_data(event);
-        entry->state_data = *it;
-        if (!filter_check_discard(call, entry, buffer, event))
-                trace_buffer_unlock_commit(buffer, event, 0, 0);
- out:
-        preempt_enable();
-}
-
-static void probe_power_mark(struct power_trace *it, unsigned int type,
-                                unsigned int level)
-{
-        struct ftrace_event_call *call = &event_power;
-        struct ring_buffer_event *event;
-        struct ring_buffer *buffer;
-        struct trace_power *entry;
-        struct trace_array_cpu *data;
-        struct trace_array *tr = power_trace;
-
-        if (!trace_power_enabled)
-                return;
-
-        buffer = tr->buffer;
-
-        memset(it, 0, sizeof(struct power_trace));
-        it->state = level;
-        it->type = type;
-        it->stamp = ktime_get();
-        preempt_disable();
-        it->end = it->stamp;
-        data = tr->data[smp_processor_id()];
-
-        event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
-                                          sizeof(*entry), 0, 0);
-        if (!event)
-                goto out;
-        entry   = ring_buffer_event_data(event);
-        entry->state_data = *it;
-        if (!filter_check_discard(call, entry, buffer, event))
-                trace_buffer_unlock_commit(buffer, event, 0, 0);
- out:
-        preempt_enable();
-}
-
-static int tracing_power_register(void)
-{
-        int ret;
-
-        ret = register_trace_power_start(probe_power_start);
-        if (ret) {
-                pr_info("power trace: Couldn't activate tracepoint"
-                        " probe to trace_power_start\n");
-                return ret;
-        }
-        ret = register_trace_power_end(probe_power_end);
-        if (ret) {
-                pr_info("power trace: Couldn't activate tracepoint"
-                        " probe to trace_power_end\n");
-                goto fail_start;
-        }
-        ret = register_trace_power_mark(probe_power_mark);
-        if (ret) {
-                pr_info("power trace: Couldn't activate tracepoint"
-                        " probe to trace_power_mark\n");
-                goto fail_end;
-        }
-        return ret;
-fail_end:
-        unregister_trace_power_end(probe_power_end);
-fail_start:
-        unregister_trace_power_start(probe_power_start);
-        return ret;
-}
-
-static void start_power_trace(struct trace_array *tr)
-{
-        trace_power_enabled = 1;
-}
-
-static void stop_power_trace(struct trace_array *tr)
-{
-        trace_power_enabled = 0;
-}
-
-static void power_trace_reset(struct trace_array *tr)
-{
-        trace_power_enabled = 0;
-        unregister_trace_power_start(probe_power_start);
-        unregister_trace_power_end(probe_power_end);
-        unregister_trace_power_mark(probe_power_mark);
-}
-
-
-static int power_trace_init(struct trace_array *tr)
-{
-        power_trace = tr;
-
-        trace_power_enabled = 1;
-        tracing_power_register();
-
-        tracing_reset_online_cpus(tr);
-        return 0;
-}
-
-static enum print_line_t power_print_line(struct trace_iterator *iter)
-{
-        int ret = 0;
-        struct trace_entry *entry = iter->ent;
-        struct trace_power *field ;
-        struct power_trace *it;
-        struct trace_seq *s = &iter->seq;
-        struct timespec stamp;
-        struct timespec duration;
-
-        trace_assign_type(field, entry);
-        it = &field->state_data;
-        stamp = ktime_to_timespec(it->stamp);
-        duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));
-
-        if (entry->type == TRACE_POWER) {
-                if (it->type == POWER_CSTATE)
-                        ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
-                                          stamp.tv_sec,
-                                          stamp.tv_nsec,
-                                          it->state, iter->cpu,
-                                          duration.tv_sec,
-                                          duration.tv_nsec);
-                if (it->type == POWER_PSTATE)
-                        ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
-                                          stamp.tv_sec,
-                                          stamp.tv_nsec,
-                                          it->state, iter->cpu);
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
-                return TRACE_TYPE_HANDLED;
-        }
-        return TRACE_TYPE_UNHANDLED;
-}
-
-static void power_print_header(struct seq_file *s)
-{
-        seq_puts(s, "#   TIMESTAMP      STATE  EVENT\n");
-        seq_puts(s, "#       |            |      |\n");
-}
-
-static struct tracer power_tracer __read_mostly =
-{
-        .name           = "power",
-        .init           = power_trace_init,
-        .start          = start_power_trace,
-        .stop           = stop_power_trace,
-        .reset          = power_trace_reset,
-        .print_line     = power_print_line,
-        .print_header   = power_print_header,
-};
-
-static int init_power_trace(void)
-{
-        return register_tracer(&power_tracer);
-}
-device_initcall(init_power_trace);
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index 687699d365ae..2547d8813cf0 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -11,7 +11,6 @@
 #include <linux/ftrace.h>
 #include <linux/string.h>
 #include <linux/module.h>
-#include <linux/marker.h>
 #include <linux/mutex.h>
 #include <linux/ctype.h>
 #include <linux/list.h>
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 0f6facb050a1..8504ac71e4e8 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -296,14 +296,14 @@ static const struct file_operations stack_trace_fops = {
 
 int
 stack_trace_sysctl(struct ctl_table *table, int write,
-                   struct file *file, void __user *buffer, size_t *lenp,
+                   void __user *buffer, size_t *lenp,
                    loff_t *ppos)
 {
         int ret;
 
         mutex_lock(&stack_sysctl_mutex);
 
-        ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
+        ret = proc_dointvec(table, write, buffer, lenp, ppos);
 
         if (ret || !write ||
             (last_stack_tracer_enabled == !!stack_tracer_enabled))
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 8712ce3c6a0e..527e17eae575 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -2,7 +2,7 @@
 #include <trace/events/syscalls.h>
 #include <linux/kernel.h>
 #include <linux/ftrace.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <asm/syscall.h>
 
 #include "trace_output.h"
@@ -166,7 +166,7 @@ int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
                                "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
                                SYSCALL_FIELD(int, nr),
-                               SYSCALL_FIELD(unsigned long, ret));
+                               SYSCALL_FIELD(long, ret));
         if (!ret)
                 return 0;
 
@@ -212,7 +212,7 @@ int syscall_exit_define_fields(struct ftrace_event_call *call)
         if (ret)
                 return ret;
 
-        ret = trace_define_field(call, SYSCALL_FIELD(unsigned long, ret), 0,
+        ret = trace_define_field(call, SYSCALL_FIELD(long, ret), 0,
                                  FILTER_OTHER);
 
         return ret;
@@ -384,10 +384,13 @@ static int sys_prof_refcount_exit;
 
 static void prof_syscall_enter(struct pt_regs *regs, long id)
 {
-        struct syscall_trace_enter *rec;
         struct syscall_metadata *sys_data;
+        struct syscall_trace_enter *rec;
+        unsigned long flags;
+        char *raw_data;
         int syscall_nr;
         int size;
+        int cpu;
 
         syscall_nr = syscall_get_nr(current, regs);
         if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
@@ -402,20 +405,38 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
         size = ALIGN(size + sizeof(u32), sizeof(u64));
         size -= sizeof(u32);
 
-        do {
-                char raw_data[size];
+        if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+                      "profile buffer not large enough"))
+                return;
+
+        /* Protect the per cpu buffer, begin the rcu read side */
+        local_irq_save(flags);
 
-                /* zero the dead bytes from align to not leak stack to user */
-                *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+        cpu = smp_processor_id();
+
+        if (in_nmi())
+                raw_data = rcu_dereference(trace_profile_buf_nmi);
+        else
+                raw_data = rcu_dereference(trace_profile_buf);
+
+        if (!raw_data)
+                goto end;
 
-                rec = (struct syscall_trace_enter *) raw_data;
-                tracing_generic_entry_update(&rec->ent, 0, 0);
-                rec->ent.type = sys_data->enter_id;
-                rec->nr = syscall_nr;
-                syscall_get_arguments(current, regs, 0, sys_data->nb_args,
-                                       (unsigned long *)&rec->args);
-                perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
-        } while(0);
+        raw_data = per_cpu_ptr(raw_data, cpu);
+
+        /* zero the dead bytes from align to not leak stack to user */
+        *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+        rec = (struct syscall_trace_enter *) raw_data;
+        tracing_generic_entry_update(&rec->ent, 0, 0);
+        rec->ent.type = sys_data->enter_id;
+        rec->nr = syscall_nr;
+        syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+                               (unsigned long *)&rec->args);
+        perf_tp_event(sys_data->enter_id, 0, 1, rec, size);
+
+end:
+        local_irq_restore(flags);
 }
 
 int reg_prof_syscall_enter(char *name)
@@ -460,8 +481,12 @@ void unreg_prof_syscall_enter(char *name)
 static void prof_syscall_exit(struct pt_regs *regs, long ret)
 {
         struct syscall_metadata *sys_data;
-        struct syscall_trace_exit rec;
+        struct syscall_trace_exit *rec;
+        unsigned long flags;
         int syscall_nr;
+        char *raw_data;
+        int size;
+        int cpu;
 
         syscall_nr = syscall_get_nr(current, regs);
         if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
@@ -471,12 +496,46 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
         if (!sys_data)
                 return;
 
-        tracing_generic_entry_update(&rec.ent, 0, 0);
-        rec.ent.type = sys_data->exit_id;
-        rec.nr = syscall_nr;
-        rec.ret = syscall_get_return_value(current, regs);
+        /* We can probably do that at build time */
+        size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
+        size -= sizeof(u32);
 
-        perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));
+        /*
+         * Impossible, but be paranoid with the future
+         * How to put this check outside runtime?
+         */
+        if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+                "exit event has grown above profile buffer size"))
+                return;
+
+        /* Protect the per cpu buffer, begin the rcu read side */
+        local_irq_save(flags);
+        cpu = smp_processor_id();
+
+        if (in_nmi())
+                raw_data = rcu_dereference(trace_profile_buf_nmi);
+        else
+                raw_data = rcu_dereference(trace_profile_buf);
+
+        if (!raw_data)
+                goto end;
+
+        raw_data = per_cpu_ptr(raw_data, cpu);
+
+        /* zero the dead bytes from align to not leak stack to user */
+        *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+        rec = (struct syscall_trace_exit *)raw_data;
+
+        tracing_generic_entry_update(&rec->ent, 0, 0);
+        rec->ent.type = sys_data->exit_id;
+        rec->nr = syscall_nr;
+        rec->ret = syscall_get_return_value(current, regs);
+
+        perf_tp_event(sys_data->exit_id, 0, 1, rec, size);
+
+end:
+        local_irq_restore(flags);
 }
 
 int reg_prof_syscall_exit(char *name)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 9489a0a9b1be..cc89be5bc0f8 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -48,7 +48,7 @@ static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
 
 /*
  * Note about RCU :
- * It is used to to delay the free of multiple probes array until a quiescent
+ * It is used to delay the free of multiple probes array until a quiescent
  * state is reached.
  * Tracepoint entries modifications are protected by the tracepoints_mutex.
  */
diff --git a/kernel/uid16.c b/kernel/uid16.c
index 0314501688b9..419209893d87 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -4,7 +4,6 @@
  */
 
 #include <linux/mm.h>
-#include <linux/utsname.h>
 #include <linux/mman.h>
 #include <linux/notifier.h>
 #include <linux/reboot.h>
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 92359cc747a7..69eae358a726 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -42,14 +42,14 @@ static void put_uts(ctl_table *table, int write, void *which)
  *      Special case of dostring for the UTS structure. This has locks
  *      to observe. Should this be in kernel/sys.c ????
  */
-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
+static int proc_do_uts_string(ctl_table *table, int write,
                   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         struct ctl_table uts_table;
         int r;
         memcpy(&uts_table, table, sizeof(uts_table));
         uts_table.data = get_uts(table, write);
-        r = proc_dostring(&uts_table,write,filp,buffer,lenp, ppos);
+        r = proc_dostring(&uts_table,write,buffer,lenp, ppos);
         put_uts(table, write, uts_table.data);
         return r;
 }
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index addfe2df93b1..47cdd7e76f2b 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -640,6 +640,24 @@ int schedule_delayed_work(struct delayed_work *dwork,
 EXPORT_SYMBOL(schedule_delayed_work);
 
 /**
+ * flush_delayed_work - block until a dwork_struct's callback has terminated
+ * @dwork: the delayed work which is to be flushed
+ *
+ * Any timeout is cancelled, and any pending work is run immediately.
+ */
+void flush_delayed_work(struct delayed_work *dwork)
+{
+        if (del_timer_sync(&dwork->timer)) {
+                struct cpu_workqueue_struct *cwq;
+                cwq = wq_per_cpu(keventd_wq, get_cpu());
+                __queue_work(cwq, &dwork->work);
+                put_cpu();
+        }
+        flush_work(&dwork->work);
+}
+EXPORT_SYMBOL(flush_delayed_work);
+
+/**
  * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
  * @cpu: cpu to use
  * @dwork: job to be done