17 files changed, 420 insertions, 240 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
index 521dfa53cb99..91e1cfd734d2 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -58,6 +58,7 @@
 #include <asm/uaccess.h>
 #include <asm/div64.h>
 #include <linux/blkdev.h> /* sector_div */
+#include <linux/pid_namespace.h>
 
 /*
  * These constants control the amount of freespace that suspend and
@@ -74,7 +75,7 @@ int acct_parm[3] = {4, 2, 30};
 /*
  * External references and all of the globals.
  */
-static void do_acct_process(struct file *);
+static void do_acct_process(struct pid_namespace *ns, struct file *);
 
 /*
  * This structure is used so that all the data protected by lock
@@ -86,6 +87,7 @@ struct acct_glbs {
         volatile int            active;
         volatile int            needcheck;
         struct file             *file;
+        struct pid_namespace    *ns;
         struct timer_list       timer;
 };
 
@@ -175,9 +177,11 @@ out:
 static void acct_file_reopen(struct file *file)
 {
         struct file *old_acct = NULL;
+        struct pid_namespace *old_ns = NULL;
 
         if (acct_globals.file) {
                 old_acct = acct_globals.file;
+                old_ns = acct_globals.ns;
                 del_timer(&acct_globals.timer);
                 acct_globals.active = 0;
                 acct_globals.needcheck = 0;
@@ -185,6 +189,7 @@ static void acct_file_reopen(struct file *file)
         }
         if (file) {
                 acct_globals.file = file;
+                acct_globals.ns = get_pid_ns(task_active_pid_ns(current));
                 acct_globals.needcheck = 0;
                 acct_globals.active = 1;
                 /* It's been deleted if it was used before so this is safe */
@@ -196,8 +201,9 @@ static void acct_file_reopen(struct file *file)
         if (old_acct) {
                 mnt_unpin(old_acct->f_path.mnt);
                 spin_unlock(&acct_globals.lock);
-                do_acct_process(old_acct);
+                do_acct_process(old_ns, old_acct);
                 filp_close(old_acct, NULL);
+                put_pid_ns(old_ns);
                 spin_lock(&acct_globals.lock);
         }
 }
@@ -419,7 +425,7 @@ static u32 encode_float(u64 value)
 /*
  *  do_acct_process does all actual work. Caller holds the reference to file.
  */
-static void do_acct_process(struct file *file)
+static void do_acct_process(struct pid_namespace *ns, struct file *file)
 {
         struct pacct_struct *pacct = &current->signal->pacct;
         acct_t ac;
@@ -481,8 +487,10 @@ static void do_acct_process(struct file *file)
         ac.ac_gid16 = current->gid;
 #endif
 #if ACCT_VERSION==3
-        ac.ac_pid = current->tgid;
-        ac.ac_ppid = current->real_parent->tgid;
+        ac.ac_pid = task_tgid_nr_ns(current, ns);
+        rcu_read_lock();
+        ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns);
+        rcu_read_unlock();
 #endif
 
         spin_lock_irq(&current->sighand->siglock);
@@ -578,6 +586,7 @@ void acct_collect(long exitcode, int group_dead)
 void acct_process(void)
 {
         struct file *file = NULL;
+        struct pid_namespace *ns;
 
         /*
          * accelerate the common fastpath:
@@ -592,8 +601,10 @@ void acct_process(void)
                 return;
         }
         get_file(file);
+        ns = get_pid_ns(acct_globals.ns);
         spin_unlock(&acct_globals.lock);
 
-        do_acct_process(file);
+        do_acct_process(ns, file);
         fput(file);
+        put_pid_ns(ns);
 }
diff --git a/kernel/audit.c b/kernel/audit.c
index 10c4930c2bbf..b782b046543d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -78,9 +78,13 @@ static int	audit_default;
 /* If auditing cannot proceed, audit_failure selects what happens. */
 static int      audit_failure = AUDIT_FAIL_PRINTK;
 
-/* If audit records are to be written to the netlink socket, audit_pid
- * contains the (non-zero) pid. */
+/*
+ * If audit records are to be written to the netlink socket, audit_pid
+ * contains the pid of the auditd process and audit_nlk_pid contains
+ * the pid to use to send netlink messages to that process.
+ */
 int             audit_pid;
+static int      audit_nlk_pid;
 
 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
  * to that number per second.  This prevents DoS attacks, but results in
@@ -350,7 +354,7 @@ static int kauditd_thread(void *dummy)
                 wake_up(&audit_backlog_wait);
                 if (skb) {
                         if (audit_pid) {
-                                int err = netlink_unicast(audit_sock, skb, audit_pid, 0);
+                                int err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
                                 if (err < 0) {
                                         BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */
                                         printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
@@ -626,6 +630,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                                         sid, 1);
 
                         audit_pid = new_pid;
+                        audit_nlk_pid = NETLINK_CB(skb).pid;
                 }
                 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
                         err = audit_set_rate_limit(status_get->rate_limit,
@@ -1264,8 +1269,8 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
 
 /**
  * audit_string_contains_control - does a string need to be logged in hex
- * @string - string to be checked
- * @len - max length of the string to check
+ * @string: string to be checked
+ * @len: max length of the string to check
  */
 int audit_string_contains_control(const char *string, size_t len)
 {
@@ -1280,7 +1285,7 @@ int audit_string_contains_control(const char *string, size_t len)
 /**
  * audit_log_n_untrustedstring - log a string that may contain random characters
  * @ab: audit_buffer
- * @len: lenth of string (not including trailing null)
+ * @len: length of string (not including trailing null)
  * @string: string to be logged
  *
  * This code will escape a string that is passed to it if the string
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e9c2fb01e89b..53d86b4b0ce0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2082,7 +2082,7 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file)
 
                 kfree(pidarray);
         } else {
-                ctr->buf = 0;
+                ctr->buf = NULL;
                 ctr->bufsz = 0;
         }
         file->private_data = ctr;
@@ -2614,7 +2614,7 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
 
 static int cgroupstats_open(struct inode *inode, struct file *file)
 {
-        return single_open(file, proc_cgroupstats_show, 0);
+        return single_open(file, proc_cgroupstats_show, NULL);
 }
 
 static struct file_operations proc_cgroupstats_operations = {
diff --git a/kernel/fork.c b/kernel/fork.c
index dd249c37b3a3..9c042f901570 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -394,7 +394,6 @@ void __mmdrop(struct mm_struct *mm)
 {
         BUG_ON(mm == &init_mm);
         mm_free_pgd(mm);
-        mm_free_cgroup(mm);
         destroy_context(mm);
         free_mm(mm);
 }
@@ -416,6 +415,7 @@ void mmput(struct mm_struct *mm)
                         spin_unlock(&mmlist_lock);
                 }
                 put_swap_token(mm);
+                mm_free_cgroup(mm);
                 mmdrop(mm);
         }
 }
diff --git a/kernel/futex.c b/kernel/futex.c
index 06968cd79200..e43945e995f5 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -281,7 +281,7 @@ static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
  */
 static void get_futex_key_refs(union futex_key *key)
 {
-        if (key->both.ptr == 0)
+        if (key->both.ptr == NULL)
                 return;
         switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
                 case FUT_OFF_INODE:
@@ -2158,7 +2158,7 @@ static struct file_system_type futex_fs_type = {
         .kill_sb        = kill_anon_super,
 };
 
-static int __init init(void)
+static int __init futex_init(void)
 {
         u32 curval;
         int i;
@@ -2194,4 +2194,4 @@ static int __init init(void)
 
         return 0;
 }
-__initcall(init);
+__initcall(futex_init);
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index ff90f049f8f6..04ac3a9e42cf 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -30,7 +30,7 @@ fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
         return 0;
 }
 
-static void __user *futex_uaddr(struct robust_list *entry,
+static void __user *futex_uaddr(struct robust_list __user *entry,
                                 compat_long_t futex_offset)
 {
         compat_uptr_t base = ptr_to_compat(entry);
diff --git a/kernel/marker.c b/kernel/marker.c
index 48a4ea5afffd..041c33e3e95c 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -104,18 +104,18 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
         char ptype;
 
         /*
-         * 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.
+         * preempt_disable 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.
          */
         preempt_disable();
-        ptype = ACCESS_ONCE(mdata->ptype);
+        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 = ACCESS_ONCE(mdata->single.func);
+                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();
@@ -133,7 +133,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
                  * in the fast path, so put the explicit barrier here.
                  */
                 smp_read_barrier_depends();
-                multi = ACCESS_ONCE(mdata->multi);
+                multi = mdata->multi;
                 for (i = 0; multi[i].func; i++) {
                         va_start(args, fmt);
                         multi[i].func(multi[i].probe_private, call_private, fmt,
@@ -161,13 +161,13 @@ void marker_probe_cb_noarg(const struct marker *mdata,
         char ptype;
 
         preempt_disable();
-        ptype = ACCESS_ONCE(mdata->ptype);
+        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 = ACCESS_ONCE(mdata->single.func);
+                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();
@@ -183,7 +183,7 @@ void marker_probe_cb_noarg(const struct marker *mdata,
                  * in the fast path, so put the explicit barrier here.
                  */
                 smp_read_barrier_depends();
-                multi = ACCESS_ONCE(mdata->multi);
+                multi = mdata->multi;
                 for (i = 0; multi[i].func; i++)
                         multi[i].func(multi[i].probe_private, call_private, fmt,
                                 &args);
@@ -551,9 +551,9 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
 
 /*
  * Disable a marker and its probe callback.
- * Note: only after a synchronize_sched() issued after setting elem->call to the
- * empty function insures that the original callback is not used anymore. This
- * insured by preemption disabling around the call site.
+ * 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 preempt_disable around the call site.
  */
 static void disable_marker(struct marker *elem)
 {
@@ -565,8 +565,8 @@ static void disable_marker(struct marker *elem)
         elem->ptype = 0;        /* single probe */
         /*
          * Leave the private data and id there, because removal is racy and
-         * should be done only after a synchronize_sched(). These are never used
-         * until the next initialization anyway.
+         * should be done only after an RCU period. These are never used until
+         * the next initialization anyway.
          */
 }
 
@@ -601,9 +601,6 @@ void marker_update_probe_range(struct marker *begin,
 
 /*
  * Update probes, removing the faulty probes.
- * Issues a synchronize_sched() when no reference to the module passed
- * as parameter is found in the probes so the probe module can be
- * safely unloaded from now on.
  *
  * 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
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 79833170bb9c..6233f3b4ae66 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -190,7 +190,7 @@ config APM_EMULATION
           notification of APM "events" (e.g. battery status change).
 
           In order to use APM, you will need supporting software. For location
-          and more information, read <file:Documentation/pm.txt> and the
+          and more information, read <file:Documentation/power/pm.txt> and the
           Battery Powered Linux mini-HOWTO, available from
           <http://www.tldp.org/docs.html#howto>.
 
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 72a020cabb4c..5f91a07c4eac 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -447,7 +447,7 @@ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
  *      of @bm->cur_zone_bm are updated.
  */
 
-static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
+static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
                                 void **addr, unsigned int *bit_nr)
 {
         struct zone_bitmap *zone_bm;
@@ -461,7 +461,8 @@ static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
                 while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
                         zone_bm = zone_bm->next;
 
-                        BUG_ON(!zone_bm);
+                        if (!zone_bm)
+                                return -EFAULT;
                 }
                 bm->cur.zone_bm = zone_bm;
         }
@@ -479,23 +480,40 @@ static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
         pfn -= bb->start_pfn;
         *bit_nr = pfn % BM_BITS_PER_CHUNK;
         *addr = bb->data + pfn / BM_BITS_PER_CHUNK;
+        return 0;
 }
 
 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
         void *addr;
         unsigned int bit;
+        int error;
 
-        memory_bm_find_bit(bm, pfn, &addr, &bit);
+        error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+        BUG_ON(error);
         set_bit(bit, addr);
 }
 
+static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
+{
+        void *addr;
+        unsigned int bit;
+        int error;
+
+        error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+        if (!error)
+                set_bit(bit, addr);
+        return error;
+}
+
 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
         void *addr;
         unsigned int bit;
+        int error;
 
-        memory_bm_find_bit(bm, pfn, &addr, &bit);
+        error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+        BUG_ON(error);
         clear_bit(bit, addr);
 }
 
@@ -503,8 +521,10 @@ static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
         void *addr;
         unsigned int bit;
+        int error;
 
-        memory_bm_find_bit(bm, pfn, &addr, &bit);
+        error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+        BUG_ON(error);
         return test_bit(bit, addr);
 }
 
@@ -709,8 +729,15 @@ static void mark_nosave_pages(struct memory_bitmap *bm)
                                 region->end_pfn << PAGE_SHIFT);
 
                 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
-                        if (pfn_valid(pfn))
-                                memory_bm_set_bit(bm, pfn);
+                        if (pfn_valid(pfn)) {
+                                /*
+                                 * It is safe to ignore the result of
+                                 * mem_bm_set_bit_check() here, since we won't
+                                 * touch the PFNs for which the error is
+                                 * returned anyway.
+                                 */
+                                mem_bm_set_bit_check(bm, pfn);
+                        }
         }
 }
 
diff --git a/kernel/printk.c b/kernel/printk.c
index 9adc2a473e6e..c46a20a19a15 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -616,6 +616,40 @@ asmlinkage int printk(const char *fmt, ...)
 /* cpu currently holding logbuf_lock */
 static volatile unsigned int printk_cpu = UINT_MAX;
 
+/*
+ * Can we actually use the console at this time on this cpu?
+ *
+ * Console drivers may assume that per-cpu resources have
+ * been allocated. So unless they're explicitly marked as
+ * being able to cope (CON_ANYTIME) don't call them until
+ * this CPU is officially up.
+ */
+static inline int can_use_console(unsigned int cpu)
+{
+        return cpu_online(cpu) || have_callable_console();
+}
+
+/*
+ * Try to get console ownership to actually show the kernel
+ * messages from a 'printk'. Return true (and with the
+ * console_semaphore held, and 'console_locked' set) if it
+ * is successful, false otherwise.
+ *
+ * This gets called with the 'logbuf_lock' spinlock held and
+ * interrupts disabled. It should return with 'lockbuf_lock'
+ * released but interrupts still disabled.
+ */
+static int acquire_console_semaphore_for_printk(unsigned int cpu)
+{
+        int retval = 0;
+
+        if (can_use_console(cpu))
+                retval = !try_acquire_console_sem();
+        printk_cpu = UINT_MAX;
+        spin_unlock(&logbuf_lock);
+        return retval;
+}
+
 const char printk_recursion_bug_msg [] =
                         KERN_CRIT "BUG: recent printk recursion!\n";
 static int printk_recursion_bug;
@@ -725,43 +759,22 @@ asmlinkage int vprintk(const char *fmt, va_list args)
                         log_level_unknown = 1;
         }
 
-        if (!down_trylock(&console_sem)) {
-                /*
-                 * We own the drivers.  We can drop the spinlock and
-                 * let release_console_sem() print the text, maybe ...
-                 */
-                console_locked = 1;
-                printk_cpu = UINT_MAX;
-                spin_unlock(&logbuf_lock);
+        /*
+         * Try to acquire and then immediately release the
+         * console semaphore. The release will do all the
+         * actual magic (print out buffers, wake up klogd,
+         * etc). 
+         *
+         * The acquire_console_semaphore_for_printk() function
+         * will release 'logbuf_lock' regardless of whether it
+         * actually gets the semaphore or not.
+         */
+        if (acquire_console_semaphore_for_printk(this_cpu))
+                release_console_sem();
 
-                /*
-                 * Console drivers may assume that per-cpu resources have
-                 * been allocated. So unless they're explicitly marked as
-                 * being able to cope (CON_ANYTIME) don't call them until
-                 * this CPU is officially up.
-                 */
-                if (cpu_online(smp_processor_id()) || have_callable_console()) {
-                        console_may_schedule = 0;
-                        release_console_sem();
-                } else {
-                        /* Release by hand to avoid flushing the buffer. */
-                        console_locked = 0;
-                        up(&console_sem);
-                }
-                lockdep_on();
-                raw_local_irq_restore(flags);
-        } else {
-                /*
-                 * Someone else owns the drivers.  We drop the spinlock, which
-                 * allows the semaphore holder to proceed and to call the
-                 * console drivers with the output which we just produced.
-                 */
-                printk_cpu = UINT_MAX;
-                spin_unlock(&logbuf_lock);
-                lockdep_on();
+        lockdep_on();
 out_restore_irqs:
-                raw_local_irq_restore(flags);
-        }
+        raw_local_irq_restore(flags);
 
         preempt_enable();
         return printed_len;
diff --git a/kernel/relay.c b/kernel/relay.c
index d080b9d161a7..d6204a485818 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -736,7 +736,7 @@ static int relay_file_open(struct inode *inode, struct file *filp)
         kref_get(&buf->kref);
         filp->private_data = buf;
 
-        return 0;
+        return nonseekable_open(inode, filp);
 }
 
 /**
@@ -1056,6 +1056,10 @@ static struct pipe_buf_operations relay_pipe_buf_ops = {
         .get = generic_pipe_buf_get,
 };
 
+static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)
+{
+}
+
 /*
  *      subbuf_splice_actor - splice up to one subbuf's worth of data
  */
@@ -1066,7 +1070,7 @@ static int subbuf_splice_actor(struct file *in,
                                unsigned int flags,
                                int *nonpad_ret)
 {
-        unsigned int pidx, poff, total_len, subbuf_pages, ret;
+        unsigned int pidx, poff, total_len, subbuf_pages, nr_pages, ret;
         struct rchan_buf *rbuf = in->private_data;
         unsigned int subbuf_size = rbuf->chan->subbuf_size;
         uint64_t pos = (uint64_t) *ppos;
@@ -1083,6 +1087,7 @@ static int subbuf_splice_actor(struct file *in,
                 .partial = partial,
                 .flags = flags,
                 .ops = &relay_pipe_buf_ops,
+                .spd_release = relay_page_release,
         };
 
         if (rbuf->subbufs_produced == rbuf->subbufs_consumed)
@@ -1097,8 +1102,9 @@ static int subbuf_splice_actor(struct file *in,
         subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
         pidx = (read_start / PAGE_SIZE) % subbuf_pages;
         poff = read_start & ~PAGE_MASK;
+        nr_pages = min_t(unsigned int, subbuf_pages, PIPE_BUFFERS);
 
-        for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) {
+        for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) {
                 unsigned int this_len, this_end, private;
                 unsigned int cur_pos = read_start + total_len;
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 1cb53fb1fe3d..8dcdec6fe0fe 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -301,7 +301,7 @@ struct cfs_rq {
         /* 'curr' points to currently running entity on this cfs_rq.
          * It is set to NULL otherwise (i.e when none are currently running).
          */
-        struct sched_entity *curr;
+        struct sched_entity *curr, *next;
 
         unsigned long nr_spread_over;
 
@@ -594,18 +594,14 @@ enum {
         SCHED_FEAT_NEW_FAIR_SLEEPERS    = 1,
         SCHED_FEAT_WAKEUP_PREEMPT       = 2,
         SCHED_FEAT_START_DEBIT          = 4,
-        SCHED_FEAT_TREE_AVG             = 8,
-        SCHED_FEAT_APPROX_AVG           = 16,
-        SCHED_FEAT_HRTICK               = 32,
-        SCHED_FEAT_DOUBLE_TICK          = 64,
+        SCHED_FEAT_HRTICK               = 8,
+        SCHED_FEAT_DOUBLE_TICK          = 16,
 };
 
 const_debug unsigned int sysctl_sched_features =
                 SCHED_FEAT_NEW_FAIR_SLEEPERS    * 1 |
                 SCHED_FEAT_WAKEUP_PREEMPT       * 1 |
                 SCHED_FEAT_START_DEBIT          * 1 |
-                SCHED_FEAT_TREE_AVG             * 0 |
-                SCHED_FEAT_APPROX_AVG           * 0 |
                 SCHED_FEAT_HRTICK               * 1 |
                 SCHED_FEAT_DOUBLE_TICK          * 0;
 
@@ -1056,6 +1052,49 @@ static void resched_cpu(int cpu)
         resched_task(cpu_curr(cpu));
         spin_unlock_irqrestore(&rq->lock, flags);
 }
+
+#ifdef CONFIG_NO_HZ
+/*
+ * When add_timer_on() enqueues a timer into the timer wheel of an
+ * idle CPU then this timer might expire before the next timer event
+ * which is scheduled to wake up that CPU. In case of a completely
+ * idle system the next event might even be infinite time into the
+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
+ * leaves the inner idle loop so the newly added timer is taken into
+ * account when the CPU goes back to idle and evaluates the timer
+ * wheel for the next timer event.
+ */
+void wake_up_idle_cpu(int cpu)
+{
+        struct rq *rq = cpu_rq(cpu);
+
+        if (cpu == smp_processor_id())
+                return;
+
+        /*
+         * This is safe, as this function is called with the timer
+         * wheel base lock of (cpu) held. When the CPU is on the way
+         * to idle and has not yet set rq->curr to idle then it will
+         * be serialized on the timer wheel base lock and take the new
+         * timer into account automatically.
+         */
+        if (rq->curr != rq->idle)
+                return;
+
+        /*
+         * We can set TIF_RESCHED on the idle task of the other CPU
+         * lockless. The worst case is that the other CPU runs the
+         * idle task through an additional NOOP schedule()
+         */
+        set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED);
+
+        /* NEED_RESCHED must be visible before we test polling */
+        smp_mb();
+        if (!tsk_is_polling(rq->idle))
+                smp_send_reschedule(cpu);
+}
+#endif
+
 #else
 static void __resched_task(struct task_struct *p, int tif_bit)
 {
@@ -1084,7 +1123,7 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
         u64 tmp;
 
         if (unlikely(!lw->inv_weight))
-                lw->inv_weight = (WMULT_CONST - lw->weight/2) / lw->weight + 1;
+                lw->inv_weight = (WMULT_CONST-lw->weight/2) / (lw->weight+1);
 
         tmp = (u64)delta_exec * weight;
         /*
@@ -1108,11 +1147,13 @@ calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
 static inline void update_load_add(struct load_weight *lw, unsigned long inc)
 {
         lw->weight += inc;
+        lw->inv_weight = 0;
 }
 
 static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
 {
         lw->weight -= dec;
+        lw->inv_weight = 0;
 }
 
 /*
@@ -1394,6 +1435,12 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
 {
         s64 delta;
 
+        /*
+         * Buddy candidates are cache hot:
+         */
+        if (&p->se == cfs_rq_of(&p->se)->next)
+                return 1;
+
         if (p->sched_class != &fair_sched_class)
                 return 0;
 
@@ -1853,10 +1900,11 @@ out_activate:
                 schedstat_inc(p, se.nr_wakeups_remote);
         update_rq_clock(rq);
         activate_task(rq, p, 1);
-        check_preempt_curr(rq, p);
         success = 1;
 
 out_running:
+        check_preempt_curr(rq, p);
+
         p->state = TASK_RUNNING;
 #ifdef CONFIG_SMP
         if (p->sched_class->task_wake_up)
@@ -1890,6 +1938,8 @@ static void __sched_fork(struct task_struct *p)
         p->se.exec_start                = 0;
         p->se.sum_exec_runtime          = 0;
         p->se.prev_sum_exec_runtime     = 0;
+        p->se.last_wakeup               = 0;
+        p->se.avg_overlap               = 0;
 
 #ifdef CONFIG_SCHEDSTATS
         p->se.wait_start                = 0;
@@ -3875,7 +3925,7 @@ need_resched_nonpreemptible:
 
         if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
                 if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
-                                unlikely(signal_pending(prev)))) {
+                                signal_pending(prev))) {
                         prev->state = TASK_RUNNING;
                 } else {
                         deactivate_task(rq, prev, 1);
@@ -4268,11 +4318,10 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
         oldprio = p->prio;
         on_rq = p->se.on_rq;
         running = task_current(rq, p);
-        if (on_rq) {
+        if (on_rq)
                 dequeue_task(rq, p, 0);
-                if (running)
-                        p->sched_class->put_prev_task(rq, p);
-        }
+        if (running)
+                p->sched_class->put_prev_task(rq, p);
 
         if (rt_prio(prio))
                 p->sched_class = &rt_sched_class;
@@ -4281,10 +4330,9 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
 
         p->prio = prio;
 
+        if (running)
+                p->sched_class->set_curr_task(rq);
         if (on_rq) {
-                if (running)
-                        p->sched_class->set_curr_task(rq);
-
                 enqueue_task(rq, p, 0);
 
                 check_class_changed(rq, p, prev_class, oldprio, running);
@@ -4581,19 +4629,17 @@ recheck:
         update_rq_clock(rq);
         on_rq = p->se.on_rq;
         running = task_current(rq, p);
-        if (on_rq) {
+        if (on_rq)
                 deactivate_task(rq, p, 0);
-                if (running)
-                        p->sched_class->put_prev_task(rq, p);
-        }
+        if (running)
+                p->sched_class->put_prev_task(rq, p);
 
         oldprio = p->prio;
         __setscheduler(rq, p, policy, param->sched_priority);
 
+        if (running)
+                p->sched_class->set_curr_task(rq);
         if (on_rq) {
-                if (running)
-                        p->sched_class->set_curr_task(rq);
-
                 activate_task(rq, p, 0);
 
                 check_class_changed(rq, p, prev_class, oldprio, running);
@@ -6804,6 +6850,10 @@ static int ndoms_cur;		/* number of sched domains in 'doms_cur' */
  */
 static cpumask_t fallback_doms;
 
+void __attribute__((weak)) arch_update_cpu_topology(void)
+{
+}
+
 /*
  * Set up scheduler domains and groups. Callers must hold the hotplug lock.
  * For now this just excludes isolated cpus, but could be used to
@@ -6813,6 +6863,7 @@ static int arch_init_sched_domains(const cpumask_t *cpu_map)
 {
         int err;
 
+        arch_update_cpu_topology();
         ndoms_cur = 1;
         doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
         if (!doms_cur)
@@ -6917,7 +6968,7 @@ match2:
 }
 
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-static int arch_reinit_sched_domains(void)
+int arch_reinit_sched_domains(void)
 {
         int err;
 
@@ -7618,11 +7669,10 @@ void sched_move_task(struct task_struct *tsk)
         running = task_current(rq, tsk);
         on_rq = tsk->se.on_rq;
 
-        if (on_rq) {
+        if (on_rq)
                 dequeue_task(rq, tsk, 0);
-                if (unlikely(running))
-                        tsk->sched_class->put_prev_task(rq, tsk);
-        }
+        if (unlikely(running))
+                tsk->sched_class->put_prev_task(rq, tsk);
 
         set_task_rq(tsk, task_cpu(tsk));
 
@@ -7631,11 +7681,10 @@ void sched_move_task(struct task_struct *tsk)
                 tsk->sched_class->moved_group(tsk);
 #endif
 
-        if (on_rq) {
-                if (unlikely(running))
-                        tsk->sched_class->set_curr_task(rq);
+        if (unlikely(running))
+                tsk->sched_class->set_curr_task(rq);
+        if (on_rq)
                 enqueue_task(rq, tsk, 0);
-        }
 
         task_rq_unlock(rq, &flags);
 }
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 4b5e24cf2f4a..ef358ba07683 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -288,6 +288,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
         PN(se.exec_start);
         PN(se.vruntime);
         PN(se.sum_exec_runtime);
+        PN(se.avg_overlap);
 
         nr_switches = p->nvcsw + p->nivcsw;
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e2a530515619..86a93376282c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -73,13 +73,13 @@ unsigned int sysctl_sched_batch_wakeup_granularity = 10000000UL;
 
 /*
  * SCHED_OTHER wake-up granularity.
- * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
  *
  * This option delays the preemption effects of decoupled workloads
  * and reduces their over-scheduling. Synchronous workloads will still
  * have immediate wakeup/sleep latencies.
  */
-unsigned int sysctl_sched_wakeup_granularity = 10000000UL;
+unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
 
 const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
 
@@ -175,8 +175,15 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
          * Maintain a cache of leftmost tree entries (it is frequently
          * used):
          */
-        if (leftmost)
+        if (leftmost) {
                 cfs_rq->rb_leftmost = &se->run_node;
+                /*
+                 * maintain cfs_rq->min_vruntime to be a monotonic increasing
+                 * value tracking the leftmost vruntime in the tree.
+                 */
+                cfs_rq->min_vruntime =
+                        max_vruntime(cfs_rq->min_vruntime, se->vruntime);
+        }
 
         rb_link_node(&se->run_node, parent, link);
         rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
@@ -184,8 +191,24 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 
 static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        if (cfs_rq->rb_leftmost == &se->run_node)
-                cfs_rq->rb_leftmost = rb_next(&se->run_node);
+        if (cfs_rq->rb_leftmost == &se->run_node) {
+                struct rb_node *next_node;
+                struct sched_entity *next;
+
+                next_node = rb_next(&se->run_node);
+                cfs_rq->rb_leftmost = next_node;
+
+                if (next_node) {
+                        next = rb_entry(next_node,
+                                        struct sched_entity, run_node);
+                        cfs_rq->min_vruntime =
+                                max_vruntime(cfs_rq->min_vruntime,
+                                             next->vruntime);
+                }
+        }
+
+        if (cfs_rq->next == se)
+                cfs_rq->next = NULL;
 
         rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
 }
@@ -260,12 +283,8 @@ static u64 __sched_period(unsigned long nr_running)
  */
 static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        u64 slice = __sched_period(cfs_rq->nr_running);
-
-        slice *= se->load.weight;
-        do_div(slice, cfs_rq->load.weight);
-
-        return slice;
+        return calc_delta_mine(__sched_period(cfs_rq->nr_running),
+                               se->load.weight, &cfs_rq->load);
 }
 
 /*
@@ -283,11 +302,6 @@ static u64 __sched_vslice(unsigned long rq_weight, unsigned long nr_running)
         return vslice;
 }
 
-static u64 sched_vslice(struct cfs_rq *cfs_rq)
-{
-        return __sched_vslice(cfs_rq->load.weight, cfs_rq->nr_running);
-}
-
 static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
         return __sched_vslice(cfs_rq->load.weight + se->load.weight,
@@ -303,7 +317,6 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
               unsigned long delta_exec)
 {
         unsigned long delta_exec_weighted;
-        u64 vruntime;
 
         schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
 
@@ -315,19 +328,6 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
                                                         &curr->load);
         }
         curr->vruntime += delta_exec_weighted;
-
-        /*
-         * maintain cfs_rq->min_vruntime to be a monotonic increasing
-         * value tracking the leftmost vruntime in the tree.
-         */
-        if (first_fair(cfs_rq)) {
-                vruntime = min_vruntime(curr->vruntime,
-                                __pick_next_entity(cfs_rq)->vruntime);
-        } else
-                vruntime = curr->vruntime;
-
-        cfs_rq->min_vruntime =
-                max_vruntime(cfs_rq->min_vruntime, vruntime);
 }
 
 static void update_curr(struct cfs_rq *cfs_rq)
@@ -493,16 +493,11 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 {
         u64 vruntime;
 
-        vruntime = cfs_rq->min_vruntime;
-
-        if (sched_feat(TREE_AVG)) {
-                struct sched_entity *last = __pick_last_entity(cfs_rq);
-                if (last) {
-                        vruntime += last->vruntime;
-                        vruntime >>= 1;
-                }
-        } else if (sched_feat(APPROX_AVG) && cfs_rq->nr_running)
-                vruntime += sched_vslice(cfs_rq)/2;
+        if (first_fair(cfs_rq)) {
+                vruntime = min_vruntime(cfs_rq->min_vruntime,
+                                __pick_next_entity(cfs_rq)->vruntime);
+        } else
+                vruntime = cfs_rq->min_vruntime;
 
         /*
          * The 'current' period is already promised to the current tasks,
@@ -515,8 +510,10 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 
         if (!initial) {
                 /* sleeps upto a single latency don't count. */
-                if (sched_feat(NEW_FAIR_SLEEPERS))
-                        vruntime -= sysctl_sched_latency;
+                if (sched_feat(NEW_FAIR_SLEEPERS)) {
+                        vruntime -= calc_delta_fair(sysctl_sched_latency,
+                                                    &cfs_rq->load);
+                }
 
                 /* ensure we never gain time by being placed backwards. */
                 vruntime = max_vruntime(se->vruntime, vruntime);
@@ -545,6 +542,21 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
         account_entity_enqueue(cfs_rq, se);
 }
 
+static void update_avg(u64 *avg, u64 sample)
+{
+        s64 diff = sample - *avg;
+        *avg += diff >> 3;
+}
+
+static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+        if (!se->last_wakeup)
+                return;
+
+        update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup);
+        se->last_wakeup = 0;
+}
+
 static void
 dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 {
@@ -555,6 +567,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 
         update_stats_dequeue(cfs_rq, se);
         if (sleep) {
+                update_avg_stats(cfs_rq, se);
 #ifdef CONFIG_SCHEDSTATS
                 if (entity_is_task(se)) {
                         struct task_struct *tsk = task_of(se);
@@ -616,12 +629,32 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
         se->prev_sum_exec_runtime = se->sum_exec_runtime;
 }
 
+static struct sched_entity *
+pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+        s64 diff, gran;
+
+        if (!cfs_rq->next)
+                return se;
+
+        diff = cfs_rq->next->vruntime - se->vruntime;
+        if (diff < 0)
+                return se;
+
+        gran = calc_delta_fair(sysctl_sched_wakeup_granularity, &cfs_rq->load);
+        if (diff > gran)
+                return se;
+
+        return cfs_rq->next;
+}
+
 static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
 {
         struct sched_entity *se = NULL;
 
         if (first_fair(cfs_rq)) {
                 se = __pick_next_entity(cfs_rq);
+                se = pick_next(cfs_rq, se);
                 set_next_entity(cfs_rq, se);
         }
 
@@ -949,96 +982,121 @@ static inline int wake_idle(int cpu, struct task_struct *p)
 #endif
 
 #ifdef CONFIG_SMP
-static int select_task_rq_fair(struct task_struct *p, int sync)
+
+static const struct sched_class fair_sched_class;
+
+static int
+wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
+            struct task_struct *p, int prev_cpu, int this_cpu, int sync,
+            int idx, unsigned long load, unsigned long this_load,
+            unsigned int imbalance)
 {
-        int cpu, this_cpu;
-        struct rq *rq;
-        struct sched_domain *sd, *this_sd = NULL;
-        int new_cpu;
+        struct task_struct *curr = this_rq->curr;
+        unsigned long tl = this_load;
+        unsigned long tl_per_task;
+
+        if (!(this_sd->flags & SD_WAKE_AFFINE))
+                return 0;
+
+        /*
+         * If the currently running task will sleep within
+         * a reasonable amount of time then attract this newly
+         * woken task:
+         */
+        if (sync && curr->sched_class == &fair_sched_class) {
+                if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
+                                p->se.avg_overlap < sysctl_sched_migration_cost)
+                        return 1;
+        }
+
+        schedstat_inc(p, se.nr_wakeups_affine_attempts);
+        tl_per_task = cpu_avg_load_per_task(this_cpu);
 
-        cpu      = task_cpu(p);
-        rq       = task_rq(p);
-        this_cpu = smp_processor_id();
-        new_cpu  = cpu;
+        /*
+         * If sync wakeup then subtract the (maximum possible)
+         * effect of the currently running task from the load
+         * of the current CPU:
+         */
+        if (sync)
+                tl -= current->se.load.weight;
+
+        if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||
+                        100*(tl + p->se.load.weight) <= imbalance*load) {
+                /*
+                 * This domain has SD_WAKE_AFFINE and
+                 * p is cache cold in this domain, and
+                 * there is no bad imbalance.
+                 */
+                schedstat_inc(this_sd, ttwu_move_affine);
+                schedstat_inc(p, se.nr_wakeups_affine);
+
+                return 1;
+        }
+        return 0;
+}
 
-        if (cpu == this_cpu)
-                goto out_set_cpu;
+static int select_task_rq_fair(struct task_struct *p, int sync)
+{
+        struct sched_domain *sd, *this_sd = NULL;
+        int prev_cpu, this_cpu, new_cpu;
+        unsigned long load, this_load;
+        struct rq *rq, *this_rq;
+        unsigned int imbalance;
+        int idx;
+
+        prev_cpu        = task_cpu(p);
+        rq              = task_rq(p);
+        this_cpu        = smp_processor_id();
+        this_rq         = cpu_rq(this_cpu);
+        new_cpu         = prev_cpu;
 
+        /*
+         * 'this_sd' is the first domain that both
+         * this_cpu and prev_cpu are present in:
+         */
         for_each_domain(this_cpu, sd) {
-                if (cpu_isset(cpu, sd->span)) {
+                if (cpu_isset(prev_cpu, sd->span)) {
                         this_sd = sd;
                         break;
                 }
         }
 
         if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
-                goto out_set_cpu;
+                goto out;
 
         /*
          * Check for affine wakeup and passive balancing possibilities.
          */
-        if (this_sd) {
-                int idx = this_sd->wake_idx;
-                unsigned int imbalance;
-                unsigned long load, this_load;
-
-                imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
-
-                load = source_load(cpu, idx);
-                this_load = target_load(this_cpu, idx);
-
-                new_cpu = this_cpu; /* Wake to this CPU if we can */
-
-                if (this_sd->flags & SD_WAKE_AFFINE) {
-                        unsigned long tl = this_load;
-                        unsigned long tl_per_task;
-
-                        /*
-                         * Attract cache-cold tasks on sync wakeups:
-                         */
-                        if (sync && !task_hot(p, rq->clock, this_sd))
-                                goto out_set_cpu;
-
-                        schedstat_inc(p, se.nr_wakeups_affine_attempts);
-                        tl_per_task = cpu_avg_load_per_task(this_cpu);
-
-                        /*
-                         * If sync wakeup then subtract the (maximum possible)
-                         * effect of the currently running task from the load
-                         * of the current CPU:
-                         */
-                        if (sync)
-                                tl -= current->se.load.weight;
-
-                        if ((tl <= load &&
-                                tl + target_load(cpu, idx) <= tl_per_task) ||
-                               100*(tl + p->se.load.weight) <= imbalance*load) {
-                                /*
-                                 * This domain has SD_WAKE_AFFINE and
-                                 * p is cache cold in this domain, and
-                                 * there is no bad imbalance.
-                                 */
-                                schedstat_inc(this_sd, ttwu_move_affine);
-                                schedstat_inc(p, se.nr_wakeups_affine);
-                                goto out_set_cpu;
-                        }
-                }
+        if (!this_sd)
+                goto out;
 
-                /*
-                 * Start passive balancing when half the imbalance_pct
-                 * limit is reached.
-                 */
-                if (this_sd->flags & SD_WAKE_BALANCE) {
-                        if (imbalance*this_load <= 100*load) {
-                                schedstat_inc(this_sd, ttwu_move_balance);
-                                schedstat_inc(p, se.nr_wakeups_passive);
-                                goto out_set_cpu;
-                        }
+        idx = this_sd->wake_idx;
+
+        imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
+
+        load = source_load(prev_cpu, idx);
+        this_load = target_load(this_cpu, idx);
+
+        if (wake_affine(rq, this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
+                                     load, this_load, imbalance))
+                return this_cpu;
+
+        if (prev_cpu == this_cpu)
+                goto out;
+
+        /*
+         * Start passive balancing when half the imbalance_pct
+         * limit is reached.
+         */
+        if (this_sd->flags & SD_WAKE_BALANCE) {
+                if (imbalance*this_load <= 100*load) {
+                        schedstat_inc(this_sd, ttwu_move_balance);
+                        schedstat_inc(p, se.nr_wakeups_passive);
+                        return this_cpu;
                 }
         }
 
-        new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */
-out_set_cpu:
+out:
         return wake_idle(new_cpu, p);
 }
 #endif /* CONFIG_SMP */
@@ -1060,6 +1118,13 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
                 resched_task(curr);
                 return;
         }
+
+        se->last_wakeup = se->sum_exec_runtime;
+        if (unlikely(se == pse))
+                return;
+
+        cfs_rq_of(pse)->next = pse;
+
         /*
          * Batch tasks do not preempt (their preemption is driven by
          * the tick):
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 548c436a776b..7f60097d443a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -141,13 +141,8 @@ static void clocksource_watchdog(unsigned long data)
         }
 
         if (!list_empty(&watchdog_list)) {
-                /* Cycle through CPUs to check if the CPUs stay synchronized to
-                 * each other. */
-                int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map);
-                if (next_cpu >= NR_CPUS)
-                        next_cpu = first_cpu(cpu_online_map);
-                watchdog_timer.expires += WATCHDOG_INTERVAL;
-                add_timer_on(&watchdog_timer, next_cpu);
+                __mod_timer(&watchdog_timer,
+                            watchdog_timer.expires + WATCHDOG_INTERVAL);
         }
         spin_unlock(&watchdog_lock);
 }
@@ -169,7 +164,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                 if (!started && watchdog) {
                         watchdog_last = watchdog->read();
                         watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
-                        add_timer_on(&watchdog_timer, first_cpu(cpu_online_map));
+                        add_timer(&watchdog_timer);
                 }
         } else {
                 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -179,7 +174,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                         if (watchdog)
                                 del_timer(&watchdog_timer);
                         watchdog = cs;
-                        init_timer_deferrable(&watchdog_timer);
+                        init_timer(&watchdog_timer);
                         watchdog_timer.function = clocksource_watchdog;
 
                         /* Reset watchdog cycles */
@@ -190,8 +185,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                                 watchdog_last = watchdog->read();
                                 watchdog_timer.expires =
                                         jiffies + WATCHDOG_INTERVAL;
-                                add_timer_on(&watchdog_timer,
-                                                first_cpu(cpu_online_map));
+                                add_timer(&watchdog_timer);
                         }
                 }
         }
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 671af612b768..a3fa587c350c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -191,8 +191,12 @@ static void change_clocksource(void)
 
         tick_clock_notify();
 
+        /*
+         * 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);
+         */
 }
 #else
 static inline void change_clocksource(void) { }
diff --git a/kernel/timer.c b/kernel/timer.c
index 99b00a25f88b..b024106daa70 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -451,10 +451,18 @@ void add_timer_on(struct timer_list *timer, int cpu)
         spin_lock_irqsave(&base->lock, flags);
         timer_set_base(timer, base);
         internal_add_timer(base, timer);
+        /*
+         * Check whether the other CPU is idle and needs to be
+         * triggered to reevaluate the timer wheel when nohz is
+         * active. We are protected against the other CPU fiddling
+         * with the timer by holding the timer base lock. This also
+         * makes sure that a CPU on the way to idle can not evaluate
+         * the timer wheel.
+         */
+        wake_up_idle_cpu(cpu);
         spin_unlock_irqrestore(&base->lock, flags);
 }
 
-
 /**
  * mod_timer - modify a timer's timeout
  * @timer: the timer to be modified