Commit 2bb81a21 authored by Liu Kai's avatar Liu Kai
Browse files

sched/qos: Fix qos throttling in SMT expelled 

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



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

When the CPU does not require SMT expelled, the QoS timer needs to be
canceled.  However, when the qos_throttled_list is empty, the system
incorrectly considers that the offline tasks are throttled by the CFS
bandwidth. As a result, the timer is not canceled and the QoS throtting is
canceled in advance.  Therefore, the expelled time of offline tasks is
shorter than expected.

Fixes: efccb199ef7c ("hungtask: fixed offline group hung task issue under high load scenarios")
Signed-off-by: default avatarLiu Kai <liukai284@huawei.com>
parent 5cb1986e

kernel/sched/fair.c

+5 −9
Original line number Diff line number Diff line
@@ -9566,10 +9566,7 @@ 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 all_is_runnable = 1;



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

		return 0;

	int cfs_bandwidth_throttle = 0;



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

				 qos_throttled_list) {
@@ -9578,22 +9575,21 @@ static int __unthrottle_qos_cfs_rqs(int cpu) 
		}



		if (throttled_hierarchy(cfs_rq))

			all_is_runnable = 0;

			cfs_bandwidth_throttle = 1;

	}



	return all_is_runnable;

	return cfs_bandwidth_throttle;

}



static int unthrottle_qos_cfs_rqs(int cpu)

{

	int res;

	res = __unthrottle_qos_cfs_rqs(cpu);

	int throttled = __unthrottle_qos_cfs_rqs(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))

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

		cancel_qos_timer(cpu);



	return cpu_rq(cpu)->cfs.h_nr_running;