diff options
author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2015-12-02 09:33:25 -0800 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2015-12-02 09:33:25 -0800 |
commit | 0eea505058740aa45486145296ef4fefbd8cab85 (patch) | |
tree | 1bc265d615b8353405a04630f610a42c48302f47 /kernel/time/timer.c | |
parent | 5e0baca8b3247f459af50947eaafc68bb8168b33 (diff) | |
parent | 31ade3b83e1821da5fbb2f11b5b3d4ab2ec39db8 (diff) |
Merge tag 'v4.4-rc3' into next
Merge with Linux 4.4-rc3 to bring in helpers for multiu-driver modules.
Diffstat (limited to 'kernel/time/timer.c')
-rw-r--r-- | kernel/time/timer.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 84190f02b521..bbc5d1114583 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -461,10 +461,17 @@ void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr) static void timer_stats_account_timer(struct timer_list *timer) { - if (likely(!timer->start_site)) + void *site; + + /* + * start_site can be concurrently reset by + * timer_stats_timer_clear_start_info() + */ + site = READ_ONCE(timer->start_site); + if (likely(!site)) return; - timer_stats_update_stats(timer, timer->start_pid, timer->start_site, + timer_stats_update_stats(timer, timer->start_pid, site, timer->function, timer->start_comm, timer->flags); } @@ -867,7 +874,7 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) if (mask == 0) return expires; - bit = find_last_bit(&mask, BITS_PER_LONG); + bit = __fls(mask); mask = (1UL << bit) - 1; @@ -970,13 +977,29 @@ EXPORT_SYMBOL(add_timer); */ void add_timer_on(struct timer_list *timer, int cpu) { - struct tvec_base *base = per_cpu_ptr(&tvec_bases, cpu); + struct tvec_base *new_base = per_cpu_ptr(&tvec_bases, cpu); + struct tvec_base *base; unsigned long flags; timer_stats_timer_set_start_info(timer); BUG_ON(timer_pending(timer) || !timer->function); - spin_lock_irqsave(&base->lock, flags); - timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu; + + /* + * If @timer was on a different CPU, it should be migrated with the + * old base locked to prevent other operations proceeding with the + * wrong base locked. See lock_timer_base(). + */ + base = lock_timer_base(timer, &flags); + if (base != new_base) { + timer->flags |= TIMER_MIGRATING; + + spin_unlock(&base->lock); + base = new_base; + spin_lock(&base->lock); + WRITE_ONCE(timer->flags, + (timer->flags & ~TIMER_BASEMASK) | cpu); + } + debug_activate(timer, timer->expires); internal_add_timer(base, timer); spin_unlock_irqrestore(&base->lock, flags); |