From 80cc1d1d5ee35701daf11725ce06d8a240588973 Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Tue, 10 Oct 2023 16:41:07 +0800 Subject: [PATCH] sched/psi: Avoid updating PSI triggers and ->rtpoll_total when there are no state changes When psimon wakes up and there are no state changes for ->rtpoll_states, it's unnecessary to update triggers and ->rtpoll_total because the pressures being monitored by the user have not changed. This will help to slightly reduce unnecessary computations of PSI. [ mingo: Changelog updates ] Signed-off-by: Yang Yang Signed-off-by: Ingo Molnar Cc: Johannes Weiner Cc: Suren Baghdasaryan Cc: Peter Ziljstra Link: https://lore.kernel.org/r/202310101641075436843@zte.com.cn --- kernel/sched/psi.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index be853f227e40..79f8db0c6150 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -704,11 +704,12 @@ static void psi_rtpoll_work(struct psi_group *group) } if (now >= group->rtpoll_next_update) { - update_triggers(group, now, &update_total, PSI_POLL); - group->rtpoll_next_update = now + group->rtpoll_min_period; - if (update_total) + if (changed_states & group->rtpoll_states) { + update_triggers(group, now, &update_total, PSI_POLL); memcpy(group->rtpoll_total, group->total[PSI_POLL], sizeof(group->rtpoll_total)); + } + group->rtpoll_next_update = now + group->rtpoll_min_period; } psi_schedule_rtpoll_work(group,