Prev: sched: check for prev_cpu == this_cpu before calling wake_affine()
Next: (none)
From: Amerigo Wang on 31 Mar 2010 07:00
This fixes a lockdep warning when invoking destroy_workqueue(),
because the lockdep annotations are invoked under cpu_add_remove_lock.

So, move the lockdep annotations before taking cpu_add_remove_lock
in destroy_workqueue(), this will not affect the original purpose
of adding them for destroy_workqueue() etc.

However, it will affect another caller of cleanup_workqueue_thread(),
that is, workqueue_cpu_callback(). This should be fine, because there
are no other cases than cpu hotplug could call it.

Signed-off-by: WANG Cong <amwang(a)redhat.com>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Ingo Molnar <mingo(a)elte.hu>
Cc: Rusty Russell <rusty(a)rustcorp.com.au>

---
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index dee4865..0f050e2 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1025,9 +1025,6 @@ static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq)
if (cwq->thread == NULL)
return;

- lock_map_acquire(&cwq->wq->lockdep_map);
- lock_map_release(&cwq->wq->lockdep_map);
-
flush_cpu_workqueue(cwq);
/*
* If the caller is CPU_POST_DEAD and cwq->worklist was not empty,
@@ -1055,6 +1052,9 @@ void destroy_workqueue(struct workqueue_struct *wq)
const struct cpumask *cpu_map = wq_cpu_map(wq);
int cpu;

+ lock_map_acquire(&wq->lockdep_map);
+ lock_map_release(&wq->lockdep_map);
+
cpu_maps_update_begin();
spin_lock(&workqueue_lock);
list_del(&wq->list);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: sched: check for prev_cpu == this_cpu before calling wake_affine()
Next: (none)