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sched: Move periodic share updates to entity_tick()

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Long running entities that do not block (dequeue) require periodic updates to
maintain accurate share values.  (Note: group entities with several threads are
quite likely to be non-blocking in many circumstances).

By virtue of being long-running however, we will see entity ticks (otherwise
the required update occurs in dequeue/put and we are done).  Thus we can move
the detection (and associated work) for these updates into the periodic path.

This restores the 'atomicity' of update_curr() with respect to accounting.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101216031038.067028969@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Paul Turner 2010-12-15 19:10:17 -08:00 committed by Ingo Molnar
parent ca680888d5
commit 43365bd7ff
1 changed files with 17 additions and 4 deletions
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21
kernel/sched_fair.c
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@ -564,10 +564,6 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
cfs_rq->load_unacc_exec_time += delta_exec;
if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
update_cfs_load(cfs_rq, 0);
update_cfs_shares(cfs_rq, 0);
}
#endif
}
@ -809,6 +805,14 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta)
reweight_entity(cfs_rq_of(se), se, shares);
}
static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
{
if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
update_cfs_load(cfs_rq, 0);
update_cfs_shares(cfs_rq, 0);
}
}
#else /* CONFIG_FAIR_GROUP_SCHED */
static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
{
@ -817,6 +821,10 @@ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
static inline void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta)
{
}
static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
{
}
#endif /* CONFIG_FAIR_GROUP_SCHED */
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
@ -1133,6 +1141,11 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
*/
update_curr(cfs_rq);
/*
* Update share accounting for long-running entities.
*/
update_entity_shares_tick(cfs_rq);
#ifdef CONFIG_SCHED_HRTICK
/*
* queued ticks are scheduled to match the slice, so don't bother