diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2009-08-10 12:33:05 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-10 14:43:09 +0200 |
| commit | 2fc391112fb6f3424435a3aa2fda887497b5f807 (patch) | |
| tree | 89cda7002d591807536dca68b6344a558b081428 | |
| parent | beda2c7ea2c15ed01eef00a997d2b0496c3a502d (diff) | |
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>
| -rw-r--r-- | include/linux/wait.h | 9 | ||||
| -rw-r--r-- | kernel/wait.c | 5 |
2 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 6788e1a4d4c..cf3c2f5dba5 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) \ diff --git a/kernel/wait.c b/kernel/wait.c index ea7c3b4275c..c4bd3d825f3 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) { |