From 73129cf4b69cd1aaa3dd5eb7900a9c349773f5ae Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Wed, 21 Feb 2024 10:05:32 +0100 Subject: timers: Optimization for timer_base_try_to_set_idle() When tick is stopped also the timer base is_idle flag is set. When reentering timer_base_try_to_set_idle() with the tick stopped, there is no need to check whether the timer base needs to be set idle again. When a timer was enqueued in the meantime, this is already handled by the tick_nohz_next_event() call which was executed before tick_nohz_stop_tick(). Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20240221090548.36600-5-anna-maria@linutronix.de --- kernel/time/timer.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'kernel/time/timer.c') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index a4b8a58d05e5..74cfe21f8fd9 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -2044,13 +2044,18 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) * timer_base_try_to_set_idle() - Try to set the idle state of the timer bases * @basej: base time jiffies * @basem: base time clock monotonic - * @idle: pointer to store the value of timer_base->is_idle + * @idle: pointer to store the value of timer_base->is_idle on return; + * *idle contains the information whether tick was already stopped * - * Returns the tick aligned clock monotonic time of the next pending - * timer or KTIME_MAX if no timer is pending. + * Returns the tick aligned clock monotonic time of the next pending timer or + * KTIME_MAX if no timer is pending. When tick was already stopped KTIME_MAX is + * returned as well. */ u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle) { + if (*idle) + return KTIME_MAX; + return __get_next_timer_interrupt(basej, basem, idle); } -- cgit v1.2.3