sched/deadline: Fix bandwidth accounting at all levels after offline migration (59d06cea) · Commits · 戴 / test

If a task happens to be throttled while the CPU it was running on gets hotplugged off, the bandwidth associated with the task is not correctly migrated with it when the replenishment timer fires (offline_migration). Fix things up, for this_bw, running_bw and total_bw, when replenishment timer fires and task is migrated (dl_task_offline_migration()). Tested-by:

Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by:

Juri Lelli <juri.lelli@redhat.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: rostedt@goodmis.org Cc: tj@kernel.org Cc: tommaso.cucinotta@santannapisa.it Link: https://lkml.kernel.org/r/20190719140000.31694-5-juri.lelli@redhat.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/sched/deadline.c

+33 −0

Original line number	Diff line number	Diff line
		@@ -529,6 +529,7 @@ static struct rq find_lock_later_rq(struct task_struct task, struct rq *rq);
		static struct rq dl_task_offline_migration(struct rq rq, struct task_struct *p)
		{
		struct rq *later_rq = NULL;
		struct dl_bw *dl_b;

		later_rq = find_lock_later_rq(p, rq);
		if (!later_rq) {
		@@ -557,6 +558,38 @@ static struct rq dl_task_offline_migration(struct rq rq, struct task_struct *p
		double_lock_balance(rq, later_rq);
		}

		if (p->dl.dl_non_contending \|\| p->dl.dl_throttled) {
		/*
		* Inactive timer is armed (or callback is running, but
		* waiting for us to release rq locks). In any case, when it
		* will fire (or continue), it will see running_bw of this
		* task migrated to later_rq (and correctly handle it).
		*/
		sub_running_bw(&p->dl, &rq->dl);
		sub_rq_bw(&p->dl, &rq->dl);

		add_rq_bw(&p->dl, &later_rq->dl);
		add_running_bw(&p->dl, &later_rq->dl);
		} else {
		sub_rq_bw(&p->dl, &rq->dl);
		add_rq_bw(&p->dl, &later_rq->dl);
		}

		/*
		* And we finally need to fixup root_domain(s) bandwidth accounting,
		* since p is still hanging out in the old (now moved to default) root
		* domain.
		*/
		dl_b = &rq->rd->dl_bw;
		raw_spin_lock(&dl_b->lock);
		__dl_sub(dl_b, p->dl.dl_bw, cpumask_weight(rq->rd->span));
		raw_spin_unlock(&dl_b->lock);

		dl_b = &later_rq->rd->dl_bw;
		raw_spin_lock(&dl_b->lock);
		__dl_add(dl_b, p->dl.dl_bw, cpumask_weight(later_rq->rd->span));
		raw_spin_unlock(&dl_b->lock);

		set_task_cpu(p, later_rq->cpu);
		double_unlock_balance(later_rq, rq);

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