Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched_stat: Update sched_info_queue/dequeue() code comments
  sched, cgroup: Fixup broken cgroup movement

1 files changed, 19 insertions, 6 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 933f3d1b62ea..f4f6a8326dd0 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -3869,13 +3869,26 @@ static void set_curr_task_fair(struct rq *rq)
 }
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
-static void moved_group_fair(struct task_struct *p, int on_rq)
+static void task_move_group_fair(struct task_struct *p, int on_rq)
 {
-        struct cfs_rq *cfs_rq = task_cfs_rq(p);
-
-        update_curr(cfs_rq);
+        /*
+         * If the task was not on the rq at the time of this cgroup movement
+         * it must have been asleep, sleeping tasks keep their ->vruntime
+         * absolute on their old rq until wakeup (needed for the fair sleeper
+         * bonus in place_entity()).
+         *
+         * If it was on the rq, we've just 'preempted' it, which does convert
+         * ->vruntime to a relative base.
+         *
+         * Make sure both cases convert their relative position when migrating
+         * to another cgroup's rq. This does somewhat interfere with the
+         * fair sleeper stuff for the first placement, but who cares.
+         */
+        if (!on_rq)
+                p->se.vruntime -= cfs_rq_of(&p->se)->min_vruntime;
+        set_task_rq(p, task_cpu(p));
         if (!on_rq)
-                place_entity(cfs_rq, &p->se, 1);
+                p->se.vruntime += cfs_rq_of(&p->se)->min_vruntime;
 }
 #endif
 
@@ -3927,7 +3940,7 @@ static const struct sched_class fair_sched_class = {
         .get_rr_interval        = get_rr_interval_fair,
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
-        .moved_group            = moved_group_fair,
+        .task_move_group        = task_move_group_fair,
 #endif
 };