diff options
| author | Dima Zavin <dima@android.com> | 2010-09-28 17:24:51 -0700 |
|---|---|---|
| committer | Colin Cross <ccross@android.com> | 2010-10-04 12:08:04 -0700 |
| commit | cbb658990449df002eb9775f0b5ad104a7114b5f (patch) | |
| tree | 4030eccaa8635fe2043f9c15c584b8e140955a24 /kernel | |
| parent | 3cfc28bd7cdb071d4c6b27c7a6aa84023ac211b6 (diff) | |
sched: normalize sleeper's vruntime during group change
If you switch the cgroup of a sleeping thread, its vruntime does
not get adjusted correctly for the difference between the
min_vruntime values of the two groups.
This patch adds a new callback, prep_move_task, to struct sched_class
to give sched_fair the opportunity to adjust the task's vruntime
just before setting its new group. This allows us to properly normalize
a sleeping task's vruntime when moving it between different cgroups.
More details about the problem:
http://lkml.org/lkml/2010/9/28/24
Cc: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Dima Zavin <dima@android.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 5 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 14 |
2 files changed, 18 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 5e1142e7b9a7..17c6925e2016 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -8309,6 +8309,11 @@ void sched_move_task(struct task_struct *tsk) if (unlikely(running)) tsk->sched_class->put_prev_task(rq, tsk); +#ifdef CONFIG_FAIR_GROUP_SCHED + if (tsk->sched_class->prep_move_group) + tsk->sched_class->prep_move_group(tsk, on_rq); +#endif + set_task_rq(tsk, task_cpu(tsk)); #ifdef CONFIG_FAIR_GROUP_SCHED diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index db3f674ca49d..6ded59f453c0 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -3827,10 +3827,21 @@ static void set_curr_task_fair(struct rq *rq) static void moved_group_fair(struct task_struct *p, int on_rq) { struct cfs_rq *cfs_rq = task_cfs_rq(p); + struct sched_entity *se = &p->se; update_curr(cfs_rq); if (!on_rq) - place_entity(cfs_rq, &p->se, 1); + se->vruntime += cfs_rq->min_vruntime; +} + +static void prep_move_group_fair(struct task_struct *p, int on_rq) +{ + struct cfs_rq *cfs_rq = task_cfs_rq(p); + struct sched_entity *se = &p->se; + + /* normalize the runtime of a sleeping task before moving it */ + if (!on_rq) + se->vruntime -= cfs_rq->min_vruntime; } #endif @@ -3883,6 +3894,7 @@ static const struct sched_class fair_sched_class = { #ifdef CONFIG_FAIR_GROUP_SCHED .moved_group = moved_group_fair, + .prep_move_group = prep_move_group_fair, #endif }; |