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

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* '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()
This commit is contained in:
Linus Torvalds
2011-01-21 13:38:57 -08:00
parent 0f5c2ac58f 42c025f3de
commit 5bf7a6503f
2 changed files with 20 additions and 3 deletions
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3
include/linux/lockdep.h
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@@ -514,12 +514,15 @@ static inline void print_irqtrace_events(struct task_struct *curr)
#ifdef CONFIG_DEBUG_LOCK_ALLOC #ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING # ifdef CONFIG_PROVE_LOCKING
# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_) # 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 # else
# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_) # 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 # endif
# define lock_map_release(l) lock_release(l, 1, _THIS_IP_) # define lock_map_release(l) lock_release(l, 1, _THIS_IP_)
#else #else
# define lock_map_acquire(l) do { } while (0) # 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) # define lock_map_release(l) do { } while (0)
#endif #endif

20
kernel/workqueue.c
View File

@@ -768,7 +768,11 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
worker->flags &= ~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 ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING))
if (!(worker->flags & WORKER_NOT_RUNNING)) if (!(worker->flags & WORKER_NOT_RUNNING))
atomic_inc(get_gcwq_nr_running(gcwq->cpu)); atomic_inc(get_gcwq_nr_running(gcwq->cpu));
@@ -1840,7 +1844,7 @@ __acquires(&gcwq->lock)
spin_unlock_irq(&gcwq->lock); spin_unlock_irq(&gcwq->lock);
work_clear_pending(work); work_clear_pending(work);
lock_map_acquire(&cwq->wq->lockdep_map); lock_map_acquire_read(&cwq->wq->lockdep_map);
lock_map_acquire(&lockdep_map); lock_map_acquire(&lockdep_map);
trace_workqueue_execute_start(work); trace_workqueue_execute_start(work);
f(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); insert_wq_barrier(cwq, barr, work, worker);
spin_unlock_irq(&gcwq->lock); spin_unlock_irq(&gcwq->lock);
lock_map_acquire(&cwq->wq->lockdep_map); /*
* 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); lock_map_release(&cwq->wq->lockdep_map);
return true; return true;
already_gone: already_gone:
spin_unlock_irq(&gcwq->lock); spin_unlock_irq(&gcwq->lock);