Commit e2a1f85b authored by Yang Yang's avatar Yang Yang Committed by Peter Zijlstra
Browse files

sched/psi: Avoid resetting the min update period when it is unnecessary 



Psi_group's poll_min_period is determined by the minimum window size of
psi_trigger when creating new triggers. While destroying a psi_trigger,
there is no need to reset poll_min_period if the psi_trigger being
destroyed did not have the minimum window size, since in this condition
poll_min_period will remain the same as before.

Signed-off-by: default avatarYang Yang <yang.yang29@zte.com.cn>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarSuren Baghdasaryan <surenb@google.com>
Link: https://lkml.kernel.org/r/20230514163338.834345-1-surenb@google.com
parent a6fcdd8d

kernel/sched/psi.c

+10 −5
Original line number Diff line number Diff line
@@ -1407,11 +1407,16 @@ void psi_trigger_destroy(struct psi_trigger *t) 
			group->rtpoll_nr_triggers[t->state]--;

			if (!group->rtpoll_nr_triggers[t->state])

				group->rtpoll_states &= ~(1 << t->state);

			/* reset min update period for the remaining triggers */

			/*

			 * Reset min update period for the remaining triggers

			 * iff the destroying trigger had the min window size.

			 */

			if (group->rtpoll_min_period == div_u64(t->win.size, UPDATES_PER_WINDOW)) {

				list_for_each_entry(tmp, &group->rtpoll_triggers, node)

					period = min(period, div_u64(tmp->win.size,

							UPDATES_PER_WINDOW));

				group->rtpoll_min_period = period;

			}

			/* Destroy rtpoll_task when the last trigger is destroyed */

			if (group->rtpoll_states == 0) {

				group->rtpoll_until = 0;