From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Thu, 23 Mar 2006 11:00:58 +0000 (-0800)
Subject: [PATCH] BUILD_LOCK_OPS: cleanup preempt_disable() usage
X-Git-Tag: v2.6.17-rc1~1010
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ee25e96fcd78837c9f192aa655ce12a88bfd63d4;p=linux-2.6

[PATCH] BUILD_LOCK_OPS: cleanup preempt_disable() usage

This patch changes the code from:

	preempt_disable();
	for (;;) {
		...
		preempt_disable();
	}
to:
	for (;;) {
		preempt_disable();
		...
	}

which seems more clean to me and saves a couple of bytes for
each function.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 0375fcd592..d1b810782b 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -179,16 +179,16 @@ EXPORT_SYMBOL(_write_lock);
 #define BUILD_LOCK_OPS(op, locktype)					\
 void __lockfunc _##op##_lock(locktype##_t *lock)			\
 {									\
-	preempt_disable();						\
 	for (;;) {							\
+		preempt_disable();					\
 		if (likely(_raw_##op##_trylock(lock)))			\
 			break;						\
 		preempt_enable();					\
+									\
 		if (!(lock)->break_lock)				\
 			(lock)->break_lock = 1;				\
 		while (!op##_can_lock(lock) && (lock)->break_lock)	\
 			cpu_relax();					\
-		preempt_disable();					\
 	}								\
 	(lock)->break_lock = 0;						\
 }									\
@@ -199,19 +199,18 @@ unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock)	\
 {									\
 	unsigned long flags;						\
 									\
-	preempt_disable();						\
 	for (;;) {							\
+		preempt_disable();					\
 		local_irq_save(flags);					\
 		if (likely(_raw_##op##_trylock(lock)))			\
 			break;						\
 		local_irq_restore(flags);				\
-									\
 		preempt_enable();					\
+									\
 		if (!(lock)->break_lock)				\
 			(lock)->break_lock = 1;				\
 		while (!op##_can_lock(lock) && (lock)->break_lock)	\
 			cpu_relax();					\
-		preempt_disable();					\
 	}								\
 	(lock)->break_lock = 0;						\
 	return flags;							\