Merge branch 'linus' into perfcounters/core

Conflicts:
	fs/exec.c
	include/linux/init_task.h

Simple context conflicts.

1 files changed, 225 insertions, 182 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 4d84ff4c8774..3dfbff5fb1ac 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -118,6 +118,12 @@
  */
 #define RUNTIME_INF     ((u64)~0ULL)
 
+DEFINE_TRACE(sched_wait_task);
+DEFINE_TRACE(sched_wakeup);
+DEFINE_TRACE(sched_wakeup_new);
+DEFINE_TRACE(sched_switch);
+DEFINE_TRACE(sched_migrate_task);
+
 #ifdef CONFIG_SMP
 /*
  * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
@@ -261,6 +267,10 @@ struct task_group {
         struct cgroup_subsys_state css;
 #endif
 
+#ifdef CONFIG_USER_SCHED
+        uid_t uid;
+#endif
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
         /* schedulable entities of this group on each cpu */
         struct sched_entity **se;
@@ -286,6 +296,12 @@ struct task_group {
 
 #ifdef CONFIG_USER_SCHED
 
+/* Helper function to pass uid information to create_sched_user() */
+void set_tg_uid(struct user_struct *user)
+{
+        user->tg->uid = user->uid;
+}
+
 /*
  * Root task group.
  *      Every UID task group (including init_task_group aka UID-0) will
@@ -345,7 +361,9 @@ static inline struct task_group *task_group(struct task_struct *p)
         struct task_group *tg;
 
 #ifdef CONFIG_USER_SCHED
-        tg = p->user->tg;
+        rcu_read_lock();
+        tg = __task_cred(p)->user->tg;
+        rcu_read_unlock();
 #elif defined(CONFIG_CGROUP_SCHED)
         tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
                                 struct task_group, css);
@@ -586,6 +604,8 @@ struct rq {
 #ifdef CONFIG_SCHEDSTATS
         /* latency stats */
         struct sched_info rq_sched_info;
+        unsigned long long rq_cpu_time;
+        /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
 
         /* sys_sched_yield() stats */
         unsigned int yld_exp_empty;
@@ -703,45 +723,18 @@ static __read_mostly char *sched_feat_names[] = {
 
 #undef SCHED_FEAT
 
-static int sched_feat_open(struct inode *inode, struct file *filp)
-{
-        filp->private_data = inode->i_private;
-        return 0;
-}
-
-static ssize_t
-sched_feat_read(struct file *filp, char __user *ubuf,
-                size_t cnt, loff_t *ppos)
+static int sched_feat_show(struct seq_file *m, void *v)
 {
-        char *buf;
-        int r = 0;
-        int len = 0;
         int i;
 
         for (i = 0; sched_feat_names[i]; i++) {
-                len += strlen(sched_feat_names[i]);
-                len += 4;
-        }
-
-        buf = kmalloc(len + 2, GFP_KERNEL);
-        if (!buf)
-                return -ENOMEM;
-
-        for (i = 0; sched_feat_names[i]; i++) {
-                if (sysctl_sched_features & (1UL << i))
-                        r += sprintf(buf + r, "%s ", sched_feat_names[i]);
-                else
-                        r += sprintf(buf + r, "NO_%s ", sched_feat_names[i]);
+                if (!(sysctl_sched_features & (1UL << i)))
+                        seq_puts(m, "NO_");
+                seq_printf(m, "%s ", sched_feat_names[i]);
         }
+        seq_puts(m, "\n");
 
-        r += sprintf(buf + r, "\n");
-        WARN_ON(r >= len + 2);
-
-        r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-
-        kfree(buf);
-
-        return r;
+        return 0;
 }
 
 static ssize_t
@@ -786,10 +779,17 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
         return cnt;
 }
 
+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 = {
-        .open   = sched_feat_open,
-        .read   = sched_feat_read,
-        .write  = sched_feat_write,
+        .open           = sched_feat_open,
+        .write          = sched_feat_write,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
 };
 
 static __init int sched_init_debug(void)
@@ -1494,27 +1494,13 @@ static void
 update_group_shares_cpu(struct task_group *tg, int cpu,
                         unsigned long sd_shares, unsigned long sd_rq_weight)
 {
-        int boost = 0;
         unsigned long shares;
         unsigned long rq_weight;
 
         if (!tg->se[cpu])
                 return;
 
-        rq_weight = tg->cfs_rq[cpu]->load.weight;
-
-        /*
-         * If there are currently no tasks on the cpu pretend there is one of
-         * average load so that when a new task gets to run here it will not
-         * get delayed by group starvation.
-         */
-        if (!rq_weight) {
-                boost = 1;
-                rq_weight = NICE_0_LOAD;
-        }
-
-        if (unlikely(rq_weight > sd_rq_weight))
-                rq_weight = sd_rq_weight;
+        rq_weight = tg->cfs_rq[cpu]->rq_weight;
 
         /*
          *           \Sum shares * rq_weight
@@ -1522,7 +1508,7 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
          *               \Sum rq_weight
          *
          */
-        shares = (sd_shares * rq_weight) / (sd_rq_weight + 1);
+        shares = (sd_shares * rq_weight) / sd_rq_weight;
         shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES);
 
         if (abs(shares - tg->se[cpu]->load.weight) >
@@ -1531,11 +1517,7 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
                 unsigned long flags;
 
                 spin_lock_irqsave(&rq->lock, flags);
-                /*
-                 * record the actual number of shares, not the boosted amount.
-                 */
-                tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
-                tg->cfs_rq[cpu]->rq_weight = rq_weight;
+                tg->cfs_rq[cpu]->shares = shares;
 
                 __set_se_shares(tg->se[cpu], shares);
                 spin_unlock_irqrestore(&rq->lock, flags);
@@ -1549,13 +1531,23 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
  */
 static int tg_shares_up(struct task_group *tg, void *data)
 {
-        unsigned long rq_weight = 0;
+        unsigned long weight, rq_weight = 0;
         unsigned long shares = 0;
         struct sched_domain *sd = data;
         int i;
 
         for_each_cpu_mask(i, sd->span) {
-                rq_weight += tg->cfs_rq[i]->load.weight;
+                /*
+                 * If there are currently no tasks on the cpu pretend there
+                 * is one of average load so that when a new task gets to
+                 * run here it will not get delayed by group starvation.
+                 */
+                weight = tg->cfs_rq[i]->load.weight;
+                if (!weight)
+                        weight = NICE_0_LOAD;
+
+                tg->cfs_rq[i]->rq_weight = weight;
+                rq_weight += weight;
                 shares += tg->cfs_rq[i]->shares;
         }
 
@@ -1565,9 +1557,6 @@ static int tg_shares_up(struct task_group *tg, void *data)
         if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
                 shares = tg->shares;
 
-        if (!rq_weight)
-                rq_weight = cpus_weight(sd->span) * NICE_0_LOAD;
-
         for_each_cpu_mask(i, sd->span)
                 update_group_shares_cpu(tg, i, shares, rq_weight);
 
@@ -1632,6 +1621,39 @@ static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd)
 
 #endif
 
+/*
+ * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
+ */
+static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
+        __releases(this_rq->lock)
+        __acquires(busiest->lock)
+        __acquires(this_rq->lock)
+{
+        int ret = 0;
+
+        if (unlikely(!irqs_disabled())) {
+                /* printk() doesn't work good under rq->lock */
+                spin_unlock(&this_rq->lock);
+                BUG_ON(1);
+        }
+        if (unlikely(!spin_trylock(&busiest->lock))) {
+                if (busiest < this_rq) {
+                        spin_unlock(&this_rq->lock);
+                        spin_lock(&busiest->lock);
+                        spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
+                        ret = 1;
+                } else
+                        spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
+        }
+        return ret;
+}
+
+static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
+        __releases(busiest->lock)
+{
+        spin_unlock(&busiest->lock);
+        lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
+}
 #endif
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1865,6 +1887,8 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 
         clock_offset = old_rq->clock - new_rq->clock;
 
+        trace_sched_migrate_task(p, task_cpu(p), new_cpu);
+
 #ifdef CONFIG_SCHEDSTATS
         if (p->se.wait_start)
                 p->se.wait_start -= clock_offset;
@@ -2297,6 +2321,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 
         smp_wmb();
         rq = task_rq_lock(p, &flags);
+        update_rq_clock(rq);
         old_state = p->state;
         if (!(old_state & state))
                 goto out;
@@ -2354,12 +2379,11 @@ out_activate:
                 schedstat_inc(p, se.nr_wakeups_local);
         else
                 schedstat_inc(p, se.nr_wakeups_remote);
-        update_rq_clock(rq);
         activate_task(rq, p, 1);
         success = 1;
 
 out_running:
-        trace_sched_wakeup(rq, p);
+        trace_sched_wakeup(rq, p, success);
         check_preempt_curr(rq, p, sync);
 
         p->state = TASK_RUNNING;
@@ -2493,7 +2517,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
                 p->sched_class->task_new(rq, p);
                 inc_nr_running(rq);
         }
-        trace_sched_wakeup_new(rq, p);
+        trace_sched_wakeup_new(rq, p, 1);
         check_preempt_curr(rq, p, 0);
 #ifdef CONFIG_SMP
         if (p->sched_class->task_wake_up)
@@ -2857,40 +2881,6 @@ static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
 }
 
 /*
- * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
- */
-static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
-        __releases(this_rq->lock)
-        __acquires(busiest->lock)
-        __acquires(this_rq->lock)
-{
-        int ret = 0;
-
-        if (unlikely(!irqs_disabled())) {
-                /* printk() doesn't work good under rq->lock */
-                spin_unlock(&this_rq->lock);
-                BUG_ON(1);
-        }
-        if (unlikely(!spin_trylock(&busiest->lock))) {
-                if (busiest < this_rq) {
-                        spin_unlock(&this_rq->lock);
-                        spin_lock(&busiest->lock);
-                        spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
-                        ret = 1;
-                } else
-                        spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
-        }
-        return ret;
-}
-
-static void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
-        __releases(busiest->lock)
-{
-        spin_unlock(&busiest->lock);
-        lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
-}
-
-/*
  * If dest_cpu is allowed for this process, migrate the task to it.
  * This is accomplished by forcing the cpu_allowed mask to only
  * allow dest_cpu, which will force the cpu onto dest_cpu. Then
@@ -2907,7 +2897,6 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu)
             || unlikely(!cpu_active(dest_cpu)))
                 goto out;
 
-        trace_sched_migrate_task(rq, p, dest_cpu);
         /* force the process onto the specified CPU */
         if (migrate_task(p, dest_cpu, &req)) {
                 /* Need to wait for migration thread (might exit: take ref). */
@@ -3752,7 +3741,7 @@ out_balanced:
 static void idle_balance(int this_cpu, struct rq *this_rq)
 {
         struct sched_domain *sd;
-        int pulled_task = -1;
+        int pulled_task = 0;
         unsigned long next_balance = jiffies + HZ;
         cpumask_t tmpmask;
 
@@ -5204,6 +5193,22 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
         set_load_weight(p);
 }
 
+/*
+ * check the target process has a UID that matches the current process's
+ */
+static bool check_same_owner(struct task_struct *p)
+{
+        const struct cred *cred = current_cred(), *pcred;
+        bool match;
+
+        rcu_read_lock();
+        pcred = __task_cred(p);
+        match = (cred->euid == pcred->euid ||
+                 cred->euid == pcred->uid);
+        rcu_read_unlock();
+        return match;
+}
+
 static int __sched_setscheduler(struct task_struct *p, int policy,
                                 struct sched_param *param, bool user)
 {
@@ -5263,8 +5268,7 @@ recheck:
                         return -EPERM;
 
                 /* can't change other user's priorities */
-                if ((current->euid != p->euid) &&
-                    (current->euid != p->uid))
+                if (!check_same_owner(p))
                         return -EPERM;
         }
 
@@ -5496,8 +5500,7 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask)
         read_unlock(&tasklist_lock);
 
         retval = -EPERM;
-        if ((current->euid != p->euid) && (current->euid != p->uid) &&
-                        !capable(CAP_SYS_NICE))
+        if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
                 goto out_unlock;
 
         retval = security_task_setscheduler(p, 0, NULL);
@@ -5966,6 +5969,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
          * The idle tasks have their own, simple scheduling class:
          */
         idle->sched_class = &idle_sched_class;
+        ftrace_graph_init_task(idle);
 }
 
 /*
@@ -6196,7 +6200,6 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
 
 /*
  * Figure out where task on dead CPU should go, use force if necessary.
- * NOTE: interrupts should be disabled by the caller
  */
 static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
 {
@@ -6708,28 +6711,6 @@ early_initcall(migration_init);
 
 #ifdef CONFIG_SCHED_DEBUG
 
-static inline const char *sd_level_to_string(enum sched_domain_level lvl)
-{
-        switch (lvl) {
-        case SD_LV_NONE:
-                        return "NONE";
-        case SD_LV_SIBLING:
-                        return "SIBLING";
-        case SD_LV_MC:
-                        return "MC";
-        case SD_LV_CPU:
-                        return "CPU";
-        case SD_LV_NODE:
-                        return "NODE";
-        case SD_LV_ALLNODES:
-                        return "ALLNODES";
-        case SD_LV_MAX:
-                        return "MAX";
-
-        }
-        return "MAX";
-}
-
 static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                                   cpumask_t *groupmask)
 {
@@ -6749,8 +6730,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                 return -1;
         }
 
-        printk(KERN_CONT "span %s level %s\n",
-                str, sd_level_to_string(sd->level));
+        printk(KERN_CONT "span %s level %s\n", str, sd->name);
 
         if (!cpu_isset(cpu, sd->span)) {
                 printk(KERN_ERR "ERROR: domain->span does not contain "
@@ -6886,6 +6866,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
                                 SD_BALANCE_EXEC |
                                 SD_SHARE_CPUPOWER |
                                 SD_SHARE_PKG_RESOURCES);
+                if (nr_node_ids == 1)
+                        pflags &= ~SD_SERIALIZE;
         }
         if (~cflags & pflags)
                 return 0;
@@ -7406,13 +7388,21 @@ struct allmasks {
 };
 
 #if     NR_CPUS > 128
-#define SCHED_CPUMASK_ALLOC             1
-#define SCHED_CPUMASK_FREE(v)           kfree(v)
-#define SCHED_CPUMASK_DECLARE(v)        struct allmasks *v
+#define SCHED_CPUMASK_DECLARE(v)        struct allmasks *v
+static inline void sched_cpumask_alloc(struct allmasks **masks)
+{
+        *masks = kmalloc(sizeof(**masks), GFP_KERNEL);
+}
+static inline void sched_cpumask_free(struct allmasks *masks)
+{
+        kfree(masks);
+}
 #else
-#define SCHED_CPUMASK_ALLOC             0
-#define SCHED_CPUMASK_FREE(v)
-#define SCHED_CPUMASK_DECLARE(v)        struct allmasks _v, *v = &_v
+#define SCHED_CPUMASK_DECLARE(v)        struct allmasks _v, *v = &_v
+static inline void sched_cpumask_alloc(struct allmasks **masks)
+{ }
+static inline void sched_cpumask_free(struct allmasks *masks)
+{ }
 #endif
 
 #define SCHED_CPUMASK_VAR(v, a)         cpumask_t *v = (cpumask_t *) \
@@ -7488,9 +7478,8 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
                 return -ENOMEM;
         }
 
-#if SCHED_CPUMASK_ALLOC
         /* get space for all scratch cpumask variables */
-        allmasks = kmalloc(sizeof(*allmasks), GFP_KERNEL);
+        sched_cpumask_alloc(&allmasks);
         if (!allmasks) {
                 printk(KERN_WARNING "Cannot alloc cpumask array\n");
                 kfree(rd);
@@ -7499,7 +7488,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
 #endif
                 return -ENOMEM;
         }
-#endif
+
         tmpmask = (cpumask_t *)allmasks;
 
 
@@ -7753,13 +7742,13 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
                 cpu_attach_domain(sd, rd, i);
         }
 
-        SCHED_CPUMASK_FREE((void *)allmasks);
+        sched_cpumask_free(allmasks);
         return 0;
 
 #ifdef CONFIG_NUMA
 error:
         free_sched_groups(cpu_map, tmpmask);
-        SCHED_CPUMASK_FREE((void *)allmasks);
+        sched_cpumask_free(allmasks);
         kfree(rd);
         return -ENOMEM;
 #endif
@@ -7782,8 +7771,14 @@ static struct sched_domain_attr *dattr_cur;
  */
 static cpumask_t fallback_doms;
 
-void __attribute__((weak)) arch_update_cpu_topology(void)
+/*
+ * arch_update_cpu_topology lets virtualized architectures update the
+ * cpu core maps. It is supposed to return 1 if the topology changed
+ * or 0 if it stayed the same.
+ */
+int __attribute__((weak)) arch_update_cpu_topology(void)
 {
+        return 0;
 }
 
 /*
@@ -7823,8 +7818,6 @@ static void detach_destroy_domains(const cpumask_t *cpu_map)
         cpumask_t tmpmask;
         int i;
 
-        unregister_sched_domain_sysctl();
-
         for_each_cpu_mask_nr(i, *cpu_map)
                 cpu_attach_domain(NULL, &def_root_domain, i);
         synchronize_sched();
@@ -7877,17 +7870,21 @@ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
                              struct sched_domain_attr *dattr_new)
 {
         int i, j, n;
+        int new_topology;
 
         mutex_lock(&sched_domains_mutex);
 
         /* always unregister in case we don't destroy any domains */
         unregister_sched_domain_sysctl();
 
+        /* Let architecture update cpu core mappings. */
+        new_topology = arch_update_cpu_topology();
+
         n = doms_new ? ndoms_new : 0;
 
         /* Destroy deleted domains */
         for (i = 0; i < ndoms_cur; i++) {
-                for (j = 0; j < n; j++) {
+                for (j = 0; j < n && !new_topology; j++) {
                         if (cpus_equal(doms_cur[i], doms_new[j])
                             && dattrs_equal(dattr_cur, i, dattr_new, j))
                                 goto match1;
@@ -7902,12 +7899,12 @@ match1:
                 ndoms_cur = 0;
                 doms_new = &fallback_doms;
                 cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
-                dattr_new = NULL;
+                WARN_ON_ONCE(dattr_new);
         }
 
         /* Build new domains */
         for (i = 0; i < ndoms_new; i++) {
-                for (j = 0; j < ndoms_cur; j++) {
+                for (j = 0; j < ndoms_cur && !new_topology; j++) {
                         if (cpus_equal(doms_new[i], doms_cur[j])
                             && dattrs_equal(dattr_new, i, dattr_cur, j))
                                 goto match2;
@@ -8562,7 +8559,7 @@ static
 int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
 {
         struct cfs_rq *cfs_rq;
-        struct sched_entity *se, *parent_se;
+        struct sched_entity *se;
         struct rq *rq;
         int i;
 
@@ -8578,18 +8575,17 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
         for_each_possible_cpu(i) {
                 rq = cpu_rq(i);
 
-                cfs_rq = kmalloc_node(sizeof(struct cfs_rq),
-                                GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+                cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
+                                      GFP_KERNEL, cpu_to_node(i));
                 if (!cfs_rq)
                         goto err;
 
-                se = kmalloc_node(sizeof(struct sched_entity),
-                                GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+                se = kzalloc_node(sizeof(struct sched_entity),
+                                  GFP_KERNEL, cpu_to_node(i));
                 if (!se)
                         goto err;
 
-                parent_se = parent ? parent->se[i] : NULL;
-                init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent_se);
+                init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
         }
 
         return 1;
@@ -8650,7 +8646,7 @@ static
 int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
 {
         struct rt_rq *rt_rq;
-        struct sched_rt_entity *rt_se, *parent_se;
+        struct sched_rt_entity *rt_se;
         struct rq *rq;
         int i;
 
@@ -8667,18 +8663,17 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
         for_each_possible_cpu(i) {
                 rq = cpu_rq(i);
 
-                rt_rq = kmalloc_node(sizeof(struct rt_rq),
-                                GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+                rt_rq = kzalloc_node(sizeof(struct rt_rq),
+                                     GFP_KERNEL, cpu_to_node(i));
                 if (!rt_rq)
                         goto err;
 
-                rt_se = kmalloc_node(sizeof(struct sched_rt_entity),
-                                GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+                rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
+                                     GFP_KERNEL, cpu_to_node(i));
                 if (!rt_se)
                         goto err;
 
-                parent_se = parent ? parent->rt_se[i] : NULL;
-                init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent_se);
+                init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
         }
 
         return 1;
@@ -9321,11 +9316,12 @@ struct cgroup_subsys cpu_cgroup_subsys = {
  * (balbir@in.ibm.com).
  */
 
-/* track cpu usage of a group of tasks */
+/* track cpu usage of a group of tasks and its child groups */
 struct cpuacct {
         struct cgroup_subsys_state css;
         /* cpuusage holds pointer to a u64-type object on every cpu */
         u64 *cpuusage;
+        struct cpuacct *parent;
 };
 
 struct cgroup_subsys cpuacct_subsys;
@@ -9359,6 +9355,9 @@ static struct cgroup_subsys_state *cpuacct_create(
                 return ERR_PTR(-ENOMEM);
         }
 
+        if (cgrp->parent)
+                ca->parent = cgroup_ca(cgrp->parent);
+
         return &ca->css;
 }
 
@@ -9372,6 +9371,41 @@ cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
         kfree(ca);
 }
 
+static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
+{
+        u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+        u64 data;
+
+#ifndef CONFIG_64BIT
+        /*
+         * Take rq->lock to make 64-bit read safe on 32-bit platforms.
+         */
+        spin_lock_irq(&cpu_rq(cpu)->lock);
+        data = *cpuusage;
+        spin_unlock_irq(&cpu_rq(cpu)->lock);
+#else
+        data = *cpuusage;
+#endif
+
+        return data;
+}
+
+static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
+{
+        u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+
+#ifndef CONFIG_64BIT
+        /*
+         * Take rq->lock to make 64-bit write safe on 32-bit platforms.
+         */
+        spin_lock_irq(&cpu_rq(cpu)->lock);
+        *cpuusage = val;
+        spin_unlock_irq(&cpu_rq(cpu)->lock);
+#else
+        *cpuusage = val;
+#endif
+}
+
 /* return total cpu usage (in nanoseconds) of a group */
 static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
 {
@@ -9379,17 +9413,8 @@ static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
         u64 totalcpuusage = 0;
         int i;
 
-        for_each_possible_cpu(i) {
-                u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
-
-                /*
-                 * Take rq->lock to make 64-bit addition safe on 32-bit
-                 * platforms.
-                 */
-                spin_lock_irq(&cpu_rq(i)->lock);
-                totalcpuusage += *cpuusage;
-                spin_unlock_irq(&cpu_rq(i)->lock);
-        }
+        for_each_present_cpu(i)
+                totalcpuusage += cpuacct_cpuusage_read(ca, i);
 
         return totalcpuusage;
 }
@@ -9406,23 +9431,39 @@ static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
                 goto out;
         }
 
-        for_each_possible_cpu(i) {
-                u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
+        for_each_present_cpu(i)
+                cpuacct_cpuusage_write(ca, i, 0);
 
-                spin_lock_irq(&cpu_rq(i)->lock);
-                *cpuusage = 0;
-                spin_unlock_irq(&cpu_rq(i)->lock);
-        }
 out:
         return err;
 }
 
+static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
+                                   struct seq_file *m)
+{
+        struct cpuacct *ca = cgroup_ca(cgroup);
+        u64 percpu;
+        int i;
+
+        for_each_present_cpu(i) {
+                percpu = cpuacct_cpuusage_read(ca, i);
+                seq_printf(m, "%llu ", (unsigned long long) percpu);
+        }
+        seq_printf(m, "\n");
+        return 0;
+}
+
 static struct cftype files[] = {
         {
                 .name = "usage",
                 .read_u64 = cpuusage_read,
                 .write_u64 = cpuusage_write,
         },
+        {
+                .name = "usage_percpu",
+                .read_seq_string = cpuacct_percpu_seq_read,
+        },
+
 };
 
 static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
@@ -9438,14 +9479,16 @@ static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
 static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 {
         struct cpuacct *ca;
+        int cpu;
 
         if (!cpuacct_subsys.active)
                 return;
 
+        cpu = task_cpu(tsk);
         ca = task_ca(tsk);
-        if (ca) {
-                u64 *cpuusage = percpu_ptr(ca->cpuusage, task_cpu(tsk));
 
+        for (; ca; ca = ca->parent) {
+                u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
                 *cpuusage += cputime;
         }
 }