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Commit 5fca80e8 authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
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[PATCH] lockdep: add more rwsem.h documentation 



Add more documentation to rwsem.h.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f9829cce

include/linux/rwsem.h

+15 −2
Original line number Original line Diff line number Diff line
@@ -61,12 +61,25 @@ extern void downgrade_write(struct rw_semaphore *sem); 




#ifdef CONFIG_DEBUG_LOCK_ALLOC

#ifdef CONFIG_DEBUG_LOCK_ALLOC

/*

/*

 * nested locking:

 * nested locking. NOTE: rwsems are not allowed to recurse

 * (which occurs if the same task tries to acquire the same

 * lock instance multiple times), but multiple locks of the

 * same lock class might be taken, if the order of the locks

 * is always the same. This ordering rule can be expressed

 * to lockdep via the _nested() APIs, but enumerating the

 * subclasses that are used. (If the nesting relationship is

 * static then another method for expressing nested locking is

 * the explicit definition of lock class keys and the use of

 * lockdep_set_class() at lock initialization time.

 * See Documentation/lockdep-design.txt for more details.)

 */

 */

extern void down_read_nested(struct rw_semaphore *sem, int subclass);

extern void down_read_nested(struct rw_semaphore *sem, int subclass);

extern void down_write_nested(struct rw_semaphore *sem, int subclass);

extern void down_write_nested(struct rw_semaphore *sem, int subclass);

/*

/*

 * Take/release a lock when not the owner will release it:

 * Take/release a lock when not the owner will release it.

 *

 * [ This API should be avoided as much as possible - the

 *   proper abstraction for this case is completions. ]

 */

 */

extern void down_read_non_owner(struct rw_semaphore *sem);

extern void down_read_non_owner(struct rw_semaphore *sem);

extern void up_read_non_owner(struct rw_semaphore *sem);

extern void up_read_non_owner(struct rw_semaphore *sem);