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authorPeter Zijlstra <peterz@infradead.org>2009-08-10 12:33:05 +0100
committerIngo Molnar <mingo@elte.hu>2009-08-10 14:43:09 +0200
commit2fc391112fb6f3424435a3aa2fda887497b5f807 (patch)
tree89cda7002d591807536dca68b6344a558b081428 /kernel
parentbeda2c7ea2c15ed01eef00a997d2b0496c3a502d (diff)
downloadlinux-2fc391112fb6f3424435a3aa2fda887497b5f807.tar.gz
locking, sched: Give waitqueue spinlocks their own lockdep classes
Give waitqueue spinlocks their own lockdep classes when they
are initialised from init_waitqueue_head().  This means that
struct wait_queue::func functions can operate other waitqueues.

This is used by CacheFiles to catch the page from a backing fs
being unlocked and to wake up another thread to take a copy of
it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Cc: linux-cachefs@redhat.com
Cc: torvalds@osdl.org
Cc: akpm@linux-foundation.org
LKML-Reference: <20090810113305.17284.81508.stgit@warthog.procyon.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/wait.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/wait.c b/kernel/wait.c
index ea7c3b4275cf..c4bd3d825f35 100644
--- a/kernel/wait.c
+++ b/kernel/wait.c
@@ -10,13 +10,14 @@
 #include <linux/wait.h>
 #include <linux/hash.h>
 
-void init_waitqueue_head(wait_queue_head_t *q)
+void __init_waitqueue_head(wait_queue_head_t *q, struct lock_class_key *key)
 {
 	spin_lock_init(&q->lock);
+	lockdep_set_class(&q->lock, key);
 	INIT_LIST_HEAD(&q->task_list);
 }
 
-EXPORT_SYMBOL(init_waitqueue_head);
+EXPORT_SYMBOL(__init_waitqueue_head);
 
 void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
 {