kernel/time/timer.c

192  * If multiple bases need to be locked, use the base ordering for lock
208  * @lock:		Lock protecting the timer_base
209  * @running_timer:	When expiring timers, the lock is dropped. To make
220  *			prevents a life lock, when the task which tries to
252 	raw_spinlock_t		lock;
358 	 * same lock or cachelines, so we skew each extra cpu with an extra
406  * to lock contention or spurious cache line bouncing.
432  * to lock contention or spurious cache line bouncing.
642 	 * the base lock:
914  * @key: lockdep class key of the fake lock used for tracking timer
915  *       sync lock dependencies
1025  * We are using hashed locking: Holding per_cpu(timer_bases[x]).lock means
1037 	__acquires(timer->base->lock)
1052 			raw_spin_lock_irqsave(&base->lock, *flags);
1055 			raw_spin_unlock_irqrestore(&base->lock, *flags);
1094 		 * We lock timer base and calculate the bucket index right
1102 		 * while holding base lock to prevent a race against the
1136 		 * while holding base lock to prevent a race against the
1163 			raw_spin_unlock(&base->lock);
1165 			raw_spin_lock(&base->lock);
1187 	raw_spin_unlock_irqrestore(&base->lock, flags);
1370 	 * holding base lock to prevent a race against the shutdown code.
1378 		raw_spin_unlock(&base->lock);
1380 		raw_spin_lock(&base->lock);
1389 	raw_spin_unlock_irqrestore(&base->lock, flags);
1400  * timer base lock which prevents further rearming of the time. In that
1417 	 * If @shutdown is set then the lock has to be taken whether the
1419 	 * which might hit between the lockless pending check and the lock
1420 	 * acquisition. By taking the lock it is ensured that such a newly
1432 		raw_spin_unlock_irqrestore(&base->lock, flags);
1486  * timer base lock which prevents further rearming of the timer. Any
1491  * right after dropping the base lock if @shutdown is false. That
1514 	raw_spin_unlock_irqrestore(&base->lock, flags);
1527  * after dropping the base lock. That needs to be prevented by the calling
1562  * the waiter to acquire the lock and make progress.
1567 		raw_spin_unlock_irq(&base->lock);
1570 		raw_spin_lock_irq(&base->lock);
1580  * got preempted, and it prevents a life lock when the task which tries to
1593 		 * Mark the base as contended and grab the expiry lock,
1595 		 * callback. Drop the lock immediately so the softirq can
1619  *		timer base lock which prevents rearming of @timer
1622  * be rearmed concurrently, i.e. after dropping the base lock then the
1626  * base lock which prevents rearming of the timer. Any attempt to rearm
1689  * interrupt context. Even if the lock has nothing to do with the timer in
1709  * lock. If there is the possibility of a concurrent rearm then the return
1777 	 * account for lockdep too. To avoid bogus "held lock freed"
1786 	 * Couple the lock chain with the lock chain at
1804 		 * callback kept a lock held, bad luck, but not worse
1838 			raw_spin_unlock(&base->lock);
1840 			raw_spin_lock(&base->lock);
1843 			raw_spin_unlock_irq(&base->lock);
1845 			raw_spin_lock_irq(&base->lock);
1898  * hold base->lock.
2113 	lockdep_assert_held(&base_local->lock);
2114 	lockdep_assert_held(&base_global->lock);
2126 	__releases(timer_bases[BASE_LOCAL]->lock)
2127 	__releases(timer_bases[BASE_GLOBAL]->lock)
2134 	raw_spin_unlock(&base_global->lock);
2135 	raw_spin_unlock(&base_local->lock);
2139  * timer_lock_remote_bases - lock timer bases of cpu
2145 	__acquires(timer_bases[BASE_LOCAL]->lock)
2146 	__acquires(timer_bases[BASE_GLOBAL]->lock)
2155 	raw_spin_lock(&base_local->lock);
2156 	raw_spin_lock_nested(&base_global->lock, SINGLE_DEPTH_NESTING);
2249 	raw_spin_lock(&base_local->lock);
2250 	raw_spin_lock_nested(&base_global->lock, SINGLE_DEPTH_NESTING);
2319 	raw_spin_unlock(&base_global->lock);
2320 	raw_spin_unlock(&base_local->lock);
2369 	 * enqueue sending a pointless IPI, but taking the lock would just
2371 	 * for the cost of taking the lock in the exit from idle
2379 	/* Activate without holding the timer_base->lock */
2393 	lockdep_assert_held(&base->lock);
2428 	raw_spin_lock_irq(&base->lock);
2430 	raw_spin_unlock_irq(&base->lock);
2674 		raw_spin_lock_irq(&new_base->lock);
2675 		raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
2689 		raw_spin_unlock(&old_base->lock);
2690 		raw_spin_unlock_irq(&new_base->lock);
2706 		raw_spin_lock_init(&base->lock);