5 files changed, 54 insertions, 23 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 63c95afb561f..d80baaabf835 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -358,7 +358,8 @@ static cputime_t task_utime(struct task_struct *p)
         }
         utime = (clock_t)temp;
 
-        return clock_t_to_cputime(utime);
+        p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
+        return p->prev_utime;
 }
 
 static cputime_t task_stime(struct task_struct *p)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3c07d595979f..b0b1fe6e0b17 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1009,6 +1009,7 @@ struct task_struct {
         unsigned int rt_priority;
         cputime_t utime, stime, utimescaled, stimescaled;
         cputime_t gtime;
+        cputime_t prev_utime;
         unsigned long nvcsw, nivcsw; /* context switch counts */
         struct timespec start_time;             /* monotonic time */
         struct timespec real_start_time;        /* boot based time */
diff --git a/kernel/fork.c b/kernel/fork.c
index ddafdfac9456..a65bfc47177c 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1056,6 +1056,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         p->gtime = cputime_zero;
         p->utimescaled = cputime_zero;
         p->stimescaled = cputime_zero;
+        p->prev_utime = cputime_zero;
 
 #ifdef CONFIG_TASK_XACCT
         p->rchar = 0;           /* I/O counter: bytes read */
diff --git a/kernel/sched.c b/kernel/sched.c
index b4fbbc440453..3f6bd1112900 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -172,6 +172,7 @@ struct task_group {
         unsigned long shares;
         /* spinlock to serialize modification to shares */
         spinlock_t lock;
+        struct rcu_head rcu;
 };
 
 /* Default task group's sched entity on each cpu */
@@ -258,7 +259,6 @@ struct cfs_rq {
          */
         struct list_head leaf_cfs_rq_list; /* Better name : task_cfs_rq_list? */
         struct task_group *tg;    /* group that "owns" this runqueue */
-        struct rcu_head rcu;
 #endif
 };
 
@@ -3355,7 +3355,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime)
  * @p: the process that the cpu time gets accounted to
  * @cputime: the cpu time spent in virtual machine since the last update
  */
-void account_guest_time(struct task_struct *p, cputime_t cputime)
+static void account_guest_time(struct task_struct *p, cputime_t cputime)
 {
         cputime64_t tmp;
         struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
@@ -5365,7 +5365,7 @@ static struct ctl_table sd_ctl_dir[] = {
                 .procname       = "sched_domain",
                 .mode           = 0555,
         },
-        {0,},
+        {0, },
 };
 
 static struct ctl_table sd_ctl_root[] = {
@@ -5375,7 +5375,7 @@ static struct ctl_table sd_ctl_root[] = {
                 .mode           = 0555,
                 .child          = sd_ctl_dir,
         },
-        {0,},
+        {0, },
 };
 
 static struct ctl_table *sd_alloc_ctl_entry(int n)
@@ -7019,8 +7019,8 @@ err:
 /* rcu callback to free various structures associated with a task group */
 static void free_sched_group(struct rcu_head *rhp)
 {
-        struct cfs_rq *cfs_rq = container_of(rhp, struct cfs_rq, rcu);
-        struct task_group *tg = cfs_rq->tg;
+        struct task_group *tg = container_of(rhp, struct task_group, rcu);
+        struct cfs_rq *cfs_rq;
         struct sched_entity *se;
         int i;
 
@@ -7041,7 +7041,7 @@ static void free_sched_group(struct rcu_head *rhp)
 /* Destroy runqueue etc associated with a task group */
 void sched_destroy_group(struct task_group *tg)
 {
-        struct cfs_rq *cfs_rq;
+        struct cfs_rq *cfs_rq = NULL;
         int i;
 
         for_each_possible_cpu(i) {
@@ -7049,10 +7049,10 @@ void sched_destroy_group(struct task_group *tg)
                 list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
         }
 
-        cfs_rq = tg->cfs_rq[0];
+        BUG_ON(!cfs_rq);
 
         /* wait for possible concurrent references to cfs_rqs complete */
-        call_rcu(&cfs_rq->rcu, free_sched_group);
+        call_rcu(&tg->rcu, free_sched_group);
 }
 
 /* change task's runqueue when it moves between groups.
@@ -7211,25 +7211,53 @@ static u64 cpu_shares_read_uint(struct cgroup *cgrp, struct cftype *cft)
         return (u64) tg->shares;
 }
 
-static struct cftype cpu_shares = {
-        .name = "shares",
-        .read_uint = cpu_shares_read_uint,
-        .write_uint = cpu_shares_write_uint,
+static u64 cpu_usage_read(struct cgroup *cgrp, struct cftype *cft)
+{
+        struct task_group *tg = cgroup_tg(cgrp);
+        unsigned long flags;
+        u64 res = 0;
+        int i;
+
+        for_each_possible_cpu(i) {
+                /*
+                 * Lock to prevent races with updating 64-bit counters
+                 * on 32-bit arches.
+                 */
+                spin_lock_irqsave(&cpu_rq(i)->lock, flags);
+                res += tg->se[i]->sum_exec_runtime;
+                spin_unlock_irqrestore(&cpu_rq(i)->lock, flags);
+        }
+        /* Convert from ns to ms */
+        do_div(res, 1000000);
+
+        return res;
+}
+
+static struct cftype cpu_files[] = {
+        {
+                .name = "shares",
+                .read_uint = cpu_shares_read_uint,
+                .write_uint = cpu_shares_write_uint,
+        },
+        {
+                .name = "usage",
+                .read_uint = cpu_usage_read,
+        },
 };
 
 static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
 {
-        return cgroup_add_file(cont, ss, &cpu_shares);
+        return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
 }
 
 struct cgroup_subsys cpu_cgroup_subsys = {
-        .name           = "cpu",
-        .create         = cpu_cgroup_create,
-        .destroy        = cpu_cgroup_destroy,
-        .can_attach     = cpu_cgroup_can_attach,
-        .attach         = cpu_cgroup_attach,
-        .populate       = cpu_cgroup_populate,
-        .subsys_id      = cpu_cgroup_subsys_id,
+        .name           = "cpu",
+        .create         = cpu_cgroup_create,
+        .destroy        = cpu_cgroup_destroy,
+        .can_attach     = cpu_cgroup_can_attach,
+        .attach         = cpu_cgroup_attach,
+        .populate       = cpu_cgroup_populate,
+        .subsys_id      = cpu_cgroup_subsys_id,
         .early_init     = 1,
 };
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 9971831b560e..01859f662ab7 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1025,7 +1025,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr)
         }
 }
 
-#define swap(a,b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0)
+#define swap(a, b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0)
 
 /*
  * Share the fairness runtime between parent and child, thus the