diff options
| author | Anna-Maria Behnsen <anna-maria@linutronix.de> | 2024-02-21 10:05:32 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-02-22 17:52:30 +0100 |
| commit | 73129cf4b69cd1aaa3dd5eb7900a9c349773f5ae (patch) | |
| tree | 2a64ebb268d4bb9de36d266b29b5975ca53a9a56 /kernel/time | |
| parent | e2e1d724e948c87a31c18c34c6b6a193a9b2a0f0 (diff) | |
| download | linux-73129cf4b69cd1aaa3dd5eb7900a9c349773f5ae.tar.gz | |
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 <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240221090548.36600-5-anna-maria@linutronix.de
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/tick-sched.c | 2 | ||||
| -rw-r--r-- | kernel/time/timer.c | 11 |
2 files changed, 9 insertions, 4 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 344b904f520f57..f6b61338022987 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -896,7 +896,7 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu) struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); unsigned long basejiff = ts->last_jiffies; u64 basemono = ts->timer_expires_base; - bool timer_idle; + bool timer_idle = ts->tick_stopped; u64 expires; /* Make sure we won't be trying to stop it twice in a row. */ diff --git a/kernel/time/timer.c b/kernel/time/timer.c index a4b8a58d05e5fe..74cfe21f8fd992 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); } |