diff options
author | Paul Turner <pjt@google.com> | 2010-11-15 15:47:03 -0800 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2010-11-18 13:27:47 +0100 |
commit | f0d7442a5924a802b66eef79b3708f77297bfb35 (patch) | |
tree | edffcb20dca3dfe7315b128dc8948977c7c27fa8 /kernel/sched_fair.c | |
parent | 9e3081ca61147b29f52fddb4f7c6b6b82ea5eb7a (diff) | |
download | kernel_goldelico_gta04-f0d7442a5924a802b66eef79b3708f77297bfb35.zip kernel_goldelico_gta04-f0d7442a5924a802b66eef79b3708f77297bfb35.tar.gz kernel_goldelico_gta04-f0d7442a5924a802b66eef79b3708f77297bfb35.tar.bz2 |
sched: Fix load corruption from update_cfs_shares()
As part of enqueue_entity both a new entity weight and its contribution to the
queuing cfs_rq / rq are updated. Since update_cfs_shares will only update the
queueing weights when the entity is on_rq (which in this case it is not yet),
there's a dependency loop here:
update_cfs_shares needs account_entity_enqueue to update cfs_rq->load.weight
account_entity_enqueue needs the updated weight for the queuing cfs_rq load[*]
Fix this and avoid spurious dequeue/enqueues by issuing update_cfs_shares as
if we had accounted the enqueue already.
This was also resulting in rq->load corruption previously.
[*]: this dependency also exists when using the group cfs_rq w/
update_cfs_shares as the weight of the enqueued entity changes
without the load being updated.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.844900206@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r-- | kernel/sched_fair.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 46ff658..d52b97a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -718,7 +718,7 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, account_entity_enqueue(cfs_rq, se); } -static void update_cfs_shares(struct cfs_rq *cfs_rq) +static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta) { struct task_group *tg; struct sched_entity *se; @@ -732,7 +732,7 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq) if (!se) return; - load = cfs_rq->load.weight; + load = cfs_rq->load.weight + weight_delta; load_weight = atomic_read(&tg->load_weight); load_weight -= cfs_rq->load_contribution; @@ -754,7 +754,7 @@ static inline void update_cfs_load(struct cfs_rq *cfs_rq, int lb) { } -static inline void update_cfs_shares(struct cfs_rq *cfs_rq) +static inline void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta) { } #endif /* CONFIG_FAIR_GROUP_SCHED */ @@ -881,8 +881,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) */ update_curr(cfs_rq); update_cfs_load(cfs_rq, 0); + update_cfs_shares(cfs_rq, se->load.weight); account_entity_enqueue(cfs_rq, se); - update_cfs_shares(cfs_rq); if (flags & ENQUEUE_WAKEUP) { place_entity(cfs_rq, se, 0); @@ -944,7 +944,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) update_cfs_load(cfs_rq, 0); account_entity_dequeue(cfs_rq, se); update_min_vruntime(cfs_rq); - update_cfs_shares(cfs_rq); + update_cfs_shares(cfs_rq, 0); /* * Normalize the entity after updating the min_vruntime because the @@ -1177,7 +1177,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) struct cfs_rq *cfs_rq = cfs_rq_of(se); update_cfs_load(cfs_rq, 0); - update_cfs_shares(cfs_rq); + update_cfs_shares(cfs_rq, 0); } hrtick_update(rq); @@ -1207,7 +1207,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) struct cfs_rq *cfs_rq = cfs_rq_of(se); update_cfs_load(cfs_rq, 0); - update_cfs_shares(cfs_rq); + update_cfs_shares(cfs_rq, 0); } hrtick_update(rq); @@ -2034,7 +2034,7 @@ static int tg_shares_up(struct task_group *tg, int cpu) * We need to update shares after updating tg->load_weight in * order to adjust the weight of groups with long running tasks. */ - update_cfs_shares(cfs_rq); + update_cfs_shares(cfs_rq, 0); raw_spin_unlock_irqrestore(&rq->lock, flags); |