From 2367e28e231af05243b92325de9a38956ad0b565 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Tue, 16 Jul 2024 16:19:25 +0200 Subject: [PATCH] timers/migration: Spare write when nothing changed The wakeup value is written unconditionally in tmigr_cpu_new_timer(). When there was no new next timer expiry that needs to be propagated, then the value that was read before is written. This is not required. Move the write to the place where wakeup value is changed changed. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20240716-tmigr-fixes-v4-7-757baa7803fe@linutronix.de --- kernel/time/timer_migration.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index ca76120ee7c6..9c15ae8d8a25 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -1215,14 +1215,13 @@ u64 tmigr_cpu_new_timer(u64 nextexp) if (nextexp != tmc->cpuevt.nextevt.expires || tmc->cpuevt.ignore) { ret = tmigr_new_timer(tmc, nextexp); + /* + * Make sure the reevaluation of timers in idle path + * will not miss an event. + */ + WRITE_ONCE(tmc->wakeup, ret); } } - /* - * Make sure the reevaluation of timers in idle path will not miss an - * event. - */ - WRITE_ONCE(tmc->wakeup, ret); - trace_tmigr_cpu_new_timer_idle(tmc, nextexp); raw_spin_unlock(&tmc->lock); return ret;