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sched/fair: Use task_groups instead of leaf_cfs_rq_list to walk all cfs_rqs

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In order to allow leaf_cfs_rq_list to remove entries switch the
bandwidth hotplug code over to the task_groups list.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170504133122.a6qjlj3hlblbjxux@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2017-05-04 15:31:22 +02:00 committed by Ingo Molnar
parent ae4df9d6c9
commit 502ce005ab
1 changed files with 25 additions and 5 deletions
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30
kernel/sched/fair.c
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@ -4642,24 +4642,43 @@ static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
hrtimer_cancel(&cfs_b->slack_timer);
}
/*
* Both these cpu hotplug callbacks race against unregister_fair_sched_group()
*
* The race is harmless, since modifying bandwidth settings of unhooked group
* bits doesn't do much.
*/
/* cpu online calback */
static void __maybe_unused update_runtime_enabled(struct rq *rq)
{
struct cfs_rq *cfs_rq;
struct task_group *tg;
for_each_leaf_cfs_rq(rq, cfs_rq) {
struct cfs_bandwidth *cfs_b = &cfs_rq->tg->cfs_bandwidth;
lockdep_assert_held(&rq->lock);
rcu_read_lock();
list_for_each_entry_rcu(tg, &task_groups, list) {
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
raw_spin_lock(&cfs_b->lock);
cfs_rq->runtime_enabled = cfs_b->quota != RUNTIME_INF;
raw_spin_unlock(&cfs_b->lock);
}
rcu_read_unlock();
}
/* cpu offline callback */
static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
{
struct cfs_rq *cfs_rq;
struct task_group *tg;
lockdep_assert_held(&rq->lock);
rcu_read_lock();
list_for_each_entry_rcu(tg, &task_groups, list) {
struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
for_each_leaf_cfs_rq(rq, cfs_rq) {
if (!cfs_rq->runtime_enabled)
continue;
@ -4677,6 +4696,7 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
if (cfs_rq_throttled(cfs_rq))
unthrottle_cfs_rq(cfs_rq);
}
rcu_read_unlock();
}
#else /* CONFIG_CFS_BANDWIDTH */