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sched/fair: Rework throttle_count sync

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Since we already take rq->lock when creating a cgroup, use it to also
sync the throttle_count and avoid the extra state and enqueue path
branch.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Cc: linux-kernel@vger.kernel.org
[ Fixed build warning. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2016-06-22 15:14:26 +02:00 committed by Ingo Molnar
parent 599b4840b0
commit 55e16d30bd
2 changed files with 20 additions and 21 deletions
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39
kernel/sched/fair.c
View File

@ -4241,26 +4241,6 @@ static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
if (!cfs_bandwidth_used())
return;
/* Synchronize hierarchical throttle counter: */
if (unlikely(!cfs_rq->throttle_uptodate)) {
struct rq *rq = rq_of(cfs_rq);
struct cfs_rq *pcfs_rq;
struct task_group *tg;
cfs_rq->throttle_uptodate = 1;
/* Get closest up-to-date node, because leaves go first: */
for (tg = cfs_rq->tg->parent; tg; tg = tg->parent) {
pcfs_rq = tg->cfs_rq[cpu_of(rq)];
if (pcfs_rq->throttle_uptodate)
break;
}
if (tg) {
cfs_rq->throttle_count = pcfs_rq->throttle_count;
cfs_rq->throttled_clock_task = rq_clock_task(rq);
}
}
/* an active group must be handled by the update_curr()->put() path */
if (!cfs_rq->runtime_enabled || cfs_rq->curr)
return;
@ -4275,6 +4255,23 @@ static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
throttle_cfs_rq(cfs_rq);
}
static void sync_throttle(struct task_group *tg, int cpu)
{
struct cfs_rq *pcfs_rq, *cfs_rq;
if (!cfs_bandwidth_used())
return;
if (!tg->parent)
return;
cfs_rq = tg->cfs_rq[cpu];
pcfs_rq = tg->parent->cfs_rq[cpu];
cfs_rq->throttle_count = pcfs_rq->throttle_count;
pcfs_rq->throttled_clock_task = rq_clock_task(cpu_rq(cpu));
}
/* conditionally throttle active cfs_rq's from put_prev_entity() */
static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
@ -4414,6 +4411,7 @@ static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq)
static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) {}
static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq) { return false; }
static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
static inline void sync_throttle(struct task_group *tg, int cpu) {}
static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
@ -8646,6 +8644,7 @@ void online_fair_sched_group(struct task_group *tg)
raw_spin_lock_irq(&rq->lock);
post_init_entity_util_avg(se);
sync_throttle(tg, i);
raw_spin_unlock_irq(&rq->lock);
}
}

2
kernel/sched/sched.h
View File

@ -438,7 +438,7 @@ struct cfs_rq {
u64 throttled_clock, throttled_clock_task;
u64 throttled_clock_task_time;
int throttled, throttle_count, throttle_uptodate;
int throttled, throttle_count;
struct list_head throttled_list;
#endif /* CONFIG_CFS_BANDWIDTH */
#endif /* CONFIG_FAIR_GROUP_SCHED */