kernel-ark/include/asm-generic/mutex-null.h

/*
 * asm-generic/mutex-null.h
 *
 * Generic implementation of the mutex fastpath, based on NOP :-)
 *
 * This is used by the mutex-debugging infrastructure, but it can also
 * be used by architectures that (for whatever reason) want to use the
 * spinlock based slowpath.
 */
#ifndef _ASM_GENERIC_MUTEX_NULL_H
#define _ASM_GENERIC_MUTEX_NULL_H

#define __mutex_fastpath_lock(count, fail_fn)		fail_fn(count)
#define __mutex_fastpath_lock_retval(count, fail_fn)	fail_fn(count)
#define __mutex_fastpath_unlock(count, fail_fn)		fail_fn(count)
#define __mutex_fastpath_trylock(count, fail_fn)	fail_fn(count)
#define __mutex_slowpath_needs_to_unlock()		1

#endif
[PATCH] mutex subsystem, add asm-generic/mutex-[dec\|xchg\|null].h implementations Add three (generic) mutex fastpath implementations. The mutex-xchg.h implementation is atomic_xchg() based, and should work fine on every architecture. The mutex-dec.h implementation is atomic_dec_return() based - this one too should work on every architecture, but might not perform the most optimally on architectures that have no atomic-dec/inc instructions. The mutex-null.h implementation forces all calls into the slowpath. This is used for mutex debugging, but it can also be used on platforms that do not want (or need) a fastpath at all. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> 2006-01-09 23:59:17 +00:00			`/*`
			`* asm-generic/mutex-null.h`
			`*`
			`* Generic implementation of the mutex fastpath, based on NOP :-)`
			`*`
			`* This is used by the mutex-debugging infrastructure, but it can also`
			`* be used by architectures that (for whatever reason) want to use the`
			`* spinlock based slowpath.`
			`*/`
			`#ifndef _ASM_GENERIC_MUTEX_NULL_H`
			`#define _ASM_GENERIC_MUTEX_NULL_H`

[PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 2006-07-03 07:24:33 +00:00			`#define __mutex_fastpath_lock(count, fail_fn) fail_fn(count)`
			`#define __mutex_fastpath_lock_retval(count, fail_fn) fail_fn(count)`
			`#define __mutex_fastpath_unlock(count, fail_fn) fail_fn(count)`
			`#define __mutex_fastpath_trylock(count, fail_fn) fail_fn(count)`
			`#define __mutex_slowpath_needs_to_unlock() 1`
[PATCH] mutex subsystem, add asm-generic/mutex-[dec\|xchg\|null].h implementations Add three (generic) mutex fastpath implementations. The mutex-xchg.h implementation is atomic_xchg() based, and should work fine on every architecture. The mutex-dec.h implementation is atomic_dec_return() based - this one too should work on every architecture, but might not perform the most optimally on architectures that have no atomic-dec/inc instructions. The mutex-null.h implementation forces all calls into the slowpath. This is used for mutex debugging, but it can also be used on platforms that do not want (or need) a fastpath at all. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> 2006-01-09 23:59:17 +00:00
			`#endif`