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authorPeter Zijlstra <peterz@infradead.org>2009-08-10 15:33:05 +0400
committerIngo Molnar <mingo@elte.hu>2009-08-10 16:43:09 +0400
commit2fc391112fb6f3424435a3aa2fda887497b5f807 (patch)
tree89cda7002d591807536dca68b6344a558b081428 /include/linux/wait.h
parentbeda2c7ea2c15ed01eef00a997d2b0496c3a502d (diff)
downloadlinux-2fc391112fb6f3424435a3aa2fda887497b5f807.tar.xz
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 'include/linux/wait.h')
-rw-r--r--include/linux/wait.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 6788e1a4d4ca..cf3c2f5dba51 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -77,7 +77,14 @@ struct task_struct;
#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
{ .flags = word, .bit_nr = bit, }
-extern void init_waitqueue_head(wait_queue_head_t *q);
+extern void __init_waitqueue_head(wait_queue_head_t *q, struct lock_class_key *);
+
+#define init_waitqueue_head(q) \
+ do { \
+ static struct lock_class_key __key; \
+ \
+ __init_waitqueue_head((q), &__key); \
+ } while (0)
#ifdef CONFIG_LOCKDEP
# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \