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Commit 4882720b authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

semaphore: Remove mutex emulation 



Semaphores used as mutexes have been deprecated for years. Now that
all users are either converted to real semaphores or to mutexes remove
the cruft.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
LKML-Reference: <20100907125057.562399240@linutronix.de>
parent 45f4d024

include/linux/semaphore.h

+0 −6
Original line number Diff line number Diff line
@@ -29,9 +29,6 @@ struct semaphore { 
#define DEFINE_SEMAPHORE(name)	\

	struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)



#define DECLARE_MUTEX(name)	\

	struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)



static inline void sema_init(struct semaphore *sem, int val)

{

	static struct lock_class_key __key;
@@ -39,9 +36,6 @@ static inline void sema_init(struct semaphore *sem, int val) 
	lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0);

}



#define init_MUTEX(sem)		sema_init(sem, 1)

#define init_MUTEX_LOCKED(sem)	sema_init(sem, 0)



extern void down(struct semaphore *sem);

extern int __must_check down_interruptible(struct semaphore *sem);

extern int __must_check down_killable(struct semaphore *sem);

scripts/checkpatch.pl

+2 −6
Original line number Diff line number Diff line
@@ -2794,12 +2794,8 @@ sub process { 
			WARN("__func__ should be used instead of gcc specific __FUNCTION__\n"  . $herecurr);

		}



# check for semaphores used as mutexes

		if ($line =~ /^.\s*(DECLARE_MUTEX|init_MUTEX)\s*\(/) {

			WARN("mutexes are preferred for single holder semaphores\n" . $herecurr);

		}

# check for semaphores used as mutexes

		if ($line =~ /^.\s*init_MUTEX_LOCKED\s*\(/) {

# check for semaphores initialized locked

		if ($line =~ /^.\s*sema_init.+,\W?0\W?\)/) {

			WARN("consider using a completion\n" . $herecurr);



		}