So far next expiry was only tracked while the CPU was in nohz_idle mode in order to cope with missing ticks that can't increment the base->clk periodically anymore.
We are going to expand that logic beyond nohz in order to spare timers softirqs so do it unconditionally. Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Anna-Maria Gleixner <[email protected]> Cc: Juri Lelli <[email protected]> --- kernel/time/timer.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 4aa74aafdd33..30f491ec875a 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -550,8 +550,22 @@ trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer) * timer is not deferrable. If the other CPU is on the way to idle * then it can't set base->is_idle as we hold the base lock: */ - if (!base->is_idle) - return; + if (base->is_idle) + wake_up_nohz_cpu(base->cpu); +} + +/* + * Enqueue the timer into the hash bucket, mark it pending in + * the bitmap and store the index in the timer flags. + */ +static void enqueue_timer(struct timer_base *base, struct timer_list *timer, + unsigned int idx) +{ + hlist_add_head(&timer->entry, base->vectors + idx); + __set_bit(idx, base->pending_map); + timer_set_idx(timer, idx); + + trace_timer_start(timer, timer->expires, timer->flags); /* Check whether this is the new first expiring timer: */ if (time_after_eq(timer->expires, base->next_expiry)) @@ -570,21 +584,7 @@ trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer) } else { base->next_expiry = timer->expires; } - wake_up_nohz_cpu(base->cpu); -} -/* - * Enqueue the timer into the hash bucket, mark it pending in - * the bitmap and store the index in the timer flags. - */ -static void enqueue_timer(struct timer_base *base, struct timer_list *timer, - unsigned int idx) -{ - hlist_add_head(&timer->entry, base->vectors + idx); - __set_bit(idx, base->pending_map); - timer_set_idx(timer, idx); - - trace_timer_start(timer, timer->expires, timer->flags); trigger_dyntick_cpu(base, timer); } @@ -1482,7 +1482,6 @@ static int __collect_expired_timers(struct timer_base *base, return levels; } -#ifdef CONFIG_NO_HZ_COMMON /* * Find the next pending bucket of a level. Search from level start (@offset) * + @clk upwards and if nothing there, search from start of the level @@ -1574,6 +1573,7 @@ static unsigned long __next_timer_interrupt(struct timer_base *base) return next; } +#ifdef CONFIG_NO_HZ_COMMON /* * Check, if the next hrtimer event is before the next timer wheel * event: @@ -1779,6 +1779,7 @@ static inline void __run_timers(struct timer_base *base) levels = collect_expired_timers(base, heads); base->clk++; + base->next_expiry = __next_timer_interrupt(base); while (levels--) expire_timers(base, heads + levels); -- 2.26.2
