Commit 5bf7a650 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 

* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: note the nested NOT_RUNNING test in worker_clr_flags() isn't a noop
  workqueue: relax lockdep annotation on flush_work()
parents 0f5c2ac5 42c025f3

include/linux/lockdep.h

+3 −0
Original line number Diff line number Diff line
@@ -514,12 +514,15 @@ static inline void print_irqtrace_events(struct task_struct *curr) 
#ifdef CONFIG_DEBUG_LOCK_ALLOC

# ifdef CONFIG_PROVE_LOCKING

#  define lock_map_acquire(l)		lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_)

#  define lock_map_acquire_read(l)	lock_acquire(l, 0, 0, 2, 2, NULL, _THIS_IP_)

# else

#  define lock_map_acquire(l)		lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_)

#  define lock_map_acquire_read(l)	lock_acquire(l, 0, 0, 2, 1, NULL, _THIS_IP_)

# endif

# define lock_map_release(l)			lock_release(l, 1, _THIS_IP_)

#else

# define lock_map_acquire(l)			do { } while (0)

# define lock_map_acquire_read(l)		do { } while (0)

# define lock_map_release(l)			do { } while (0)

#endif

kernel/workqueue.c

+17 −3
Original line number Diff line number Diff line
@@ -768,7 +768,11 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags) 


	worker->flags &= ~flags;



	/* if transitioning out of NOT_RUNNING, increment nr_running */

	/*

	 * If transitioning out of NOT_RUNNING, increment nr_running.  Note

	 * that the nested NOT_RUNNING is not a noop.  NOT_RUNNING is mask

	 * of multiple flags, not a single flag.

	 */

	if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING))

		if (!(worker->flags & WORKER_NOT_RUNNING))

			atomic_inc(get_gcwq_nr_running(gcwq->cpu));
@@ -1840,7 +1844,7 @@ __acquires(&gcwq->lock) 
	spin_unlock_irq(&gcwq->lock);



	work_clear_pending(work);

	lock_map_acquire(&cwq->wq->lockdep_map);

	lock_map_acquire_read(&cwq->wq->lockdep_map);

	lock_map_acquire(&lockdep_map);

	trace_workqueue_execute_start(work);

	f(work);
@@ -2384,8 +2388,18 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, 
	insert_wq_barrier(cwq, barr, work, worker);

	spin_unlock_irq(&gcwq->lock);



	/*

	 * If @max_active is 1 or rescuer is in use, flushing another work

	 * item on the same workqueue may lead to deadlock.  Make sure the

	 * flusher is not running on the same workqueue by verifying write

	 * access.

	 */

	if (cwq->wq->saved_max_active == 1 || cwq->wq->flags & WQ_RESCUER)

		lock_map_acquire(&cwq->wq->lockdep_map);

	else

		lock_map_acquire_read(&cwq->wq->lockdep_map);

	lock_map_release(&cwq->wq->lockdep_map);



	return true;

already_gone:

	spin_unlock_irq(&gcwq->lock);