Commit 5cb1986e authored by Liu Kai's avatar Liu Kai
Browse files

hungtask: fixed offline group hung task issue under high load scenarios 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/release-management/issues/IBGRJE



--------------------------------

If an offline group exists and its parent group has a configured quota, and
if there are other online groups running in the parent group, when the
online groups are fully loaded and able to claim all of the parent group's
time slices, once the online groups exhaust all of the parent group's time
slices, the offline group will not be able to get scheduled.

So, if the parent group of this offline group is throttled, we will not
cancel the qos timer, which would otherwise remove the throttling of the
offline group by the online group, ensuring that the offline group can
still be scheduled.

Signed-off-by: default avatarLiu Kai <liukai284@huawei.com>
parent 56e0de56

kernel/sched/fair.c

+15 −5
Original line number Diff line number Diff line
@@ -9566,17 +9566,22 @@ static void unthrottle_qos_cfs_rq(struct cfs_rq *cfs_rq) 
static int __unthrottle_qos_cfs_rqs(int cpu)

{

	struct cfs_rq *cfs_rq, *tmp_rq;

	int res = 0;

	int all_is_runnable = 1;



	if (list_empty(&per_cpu(qos_throttled_cfs_rq, cpu)))

		return 0;



	list_for_each_entry_safe(cfs_rq, tmp_rq, &per_cpu(qos_throttled_cfs_rq, cpu),

				 qos_throttled_list) {

		if (cfs_rq_throttled(cfs_rq)) {

			unthrottle_qos_cfs_rq(cfs_rq);

			res++;

		}



		if (throttled_hierarchy(cfs_rq))

			all_is_runnable = 0;

	}



	return res;

	return all_is_runnable;

}



static int unthrottle_qos_cfs_rqs(int cpu)
@@ -9584,9 +9589,14 @@ static int unthrottle_qos_cfs_rqs(int cpu) 
	int res;

	res = __unthrottle_qos_cfs_rqs(cpu);



	if (qos_timer_is_activated(cpu) && !qos_smt_expelled(cpu))

	/*

	 * We should not cancel the timer if there is still a cfs_rq

	 * throttling after __unthrottle_qos_cfs_rqs().

	 */

	if (res && qos_timer_is_activated(cpu) && !qos_smt_expelled(cpu))

		cancel_qos_timer(cpu);

	return res;



	return cpu_rq(cpu)->cfs.h_nr_running;

}



static bool check_qos_cfs_rq(struct cfs_rq *cfs_rq)