From dc2a0f1fb2a06df09f5094f29aea56b763aa7cca Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 17 Jul 2020 16:05:46 +0200 Subject: timers: Always keep track of next expiry 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. This logic is going to be expanded beyond nohz in order to spare timer softirqs so do it unconditionally. Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Tested-by: Juri Lelli Link: https://lkml.kernel.org/r/20200717140551.29076-8-frederic@kernel.org --- kernel/time/timer.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) (limited to 'kernel/time/timer.c') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 9abc41715fd2..76fd9644638b 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -544,8 +544,7 @@ static int calc_wheel_index(unsigned long expires, unsigned long clk, } static void -trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer, - unsigned long bucket_expiry) +trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer) { if (!is_timers_nohz_active()) return; @@ -565,23 +564,8 @@ 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; - - /* - * Check whether this is the new first expiring timer. The - * effective expiry time of the timer is required here - * (bucket_expiry) instead of timer->expires. - */ - if (time_after_eq(bucket_expiry, base->next_expiry)) - return; - - /* - * Set the next expiry time and kick the CPU so it can reevaluate the - * wheel: - */ - base->next_expiry = bucket_expiry; - wake_up_nohz_cpu(base->cpu); + if (base->is_idle) + wake_up_nohz_cpu(base->cpu); } /* @@ -592,12 +576,26 @@ trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer, static void enqueue_timer(struct timer_base *base, struct timer_list *timer, unsigned int idx, unsigned long bucket_expiry) { + 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, bucket_expiry); + + /* + * Check whether this is the new first expiring timer. The + * effective expiry time of the timer is required here + * (bucket_expiry) instead of timer->expires. + */ + if (time_before(bucket_expiry, base->next_expiry)) { + /* + * Set the next expiry time and kick the CPU so it + * can reevaluate the wheel: + */ + base->next_expiry = bucket_expiry; + trigger_dyntick_cpu(base, timer); + } } static void internal_add_timer(struct timer_base *base, struct timer_list *timer) @@ -1493,7 +1491,6 @@ 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 @@ -1585,6 +1582,7 @@ 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: @@ -1790,6 +1788,7 @@ 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); @@ -2042,6 +2041,7 @@ static void __init init_timer_cpu(int cpu) base->cpu = cpu; raw_spin_lock_init(&base->lock); base->clk = jiffies; + base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA; timer_base_init_expiry_lock(base); } } -- cgit v1.2.3-58-ga151