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[PATCH] i386: Remove lock section support in semaphore.h

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Lock sections don't work the new dwarf2 unwinder
This generates slightly smaller code. It adds one more taken
jump to the fast path.

Cc: jbeulich@novell.com

Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Andi Kleen
2006-09-26 10:52:32 +02:00
committed by Andi Kleen
parent add659bf8a
commit 7ca2b49b06
1 changed files with 17 additions and 32 deletions
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49
include/asm-i386/semaphore.h
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@@ -100,13 +100,10 @@ static inline void down(struct semaphore * sem)
__asm__ __volatile__( __asm__ __volatile__(
"# atomic down operation\n\t" "# atomic down operation\n\t"
LOCK_PREFIX "decl %0\n\t" /* --sem->count */ LOCK_PREFIX "decl %0\n\t" /* --sem->count */
"js 2f\n" "jns 2f\n"
"1:\n" "\tlea %0,%%eax\n\t"
LOCK_SECTION_START("") "call __down_failed\n"
"2:\tlea %0,%%eax\n\t" "2:"
"call __down_failed\n\t"
"jmp 1b\n"
LOCK_SECTION_END
:"+m" (sem->count) :"+m" (sem->count)
: :
:"memory","ax"); :"memory","ax");
@@ -123,15 +120,12 @@ static inline int down_interruptible(struct semaphore * sem)
might_sleep(); might_sleep();
__asm__ __volatile__( __asm__ __volatile__(
"# atomic interruptible down operation\n\t" "# atomic interruptible down operation\n\t"
"xorl %0,%0\n\t"
LOCK_PREFIX "decl %1\n\t" /* --sem->count */ LOCK_PREFIX "decl %1\n\t" /* --sem->count */
"js 2f\n\t" "jns 2f\n\t"
"xorl %0,%0\n" "lea %1,%%eax\n\t"
"1:\n" "call __down_failed_interruptible\n"
LOCK_SECTION_START("") "2:"
"2:\tlea %1,%%eax\n\t"
"call __down_failed_interruptible\n\t"
"jmp 1b\n"
LOCK_SECTION_END
:"=a" (result), "+m" (sem->count) :"=a" (result), "+m" (sem->count)
: :
:"memory"); :"memory");
@@ -148,15 +142,12 @@ static inline int down_trylock(struct semaphore * sem)
__asm__ __volatile__( __asm__ __volatile__(
"# atomic interruptible down operation\n\t" "# atomic interruptible down operation\n\t"
"xorl %0,%0\n\t"
LOCK_PREFIX "decl %1\n\t" /* --sem->count */ LOCK_PREFIX "decl %1\n\t" /* --sem->count */
"js 2f\n\t" "jns 2f\n\t"
"xorl %0,%0\n" "lea %1,%%eax\n\t"
"1:\n"
LOCK_SECTION_START("")
"2:\tlea %1,%%eax\n\t"
"call __down_failed_trylock\n\t" "call __down_failed_trylock\n\t"
"jmp 1b\n" "2:\n"
LOCK_SECTION_END
:"=a" (result), "+m" (sem->count) :"=a" (result), "+m" (sem->count)
: :
:"memory"); :"memory");
@@ -166,22 +157,16 @@ static inline int down_trylock(struct semaphore * sem)
/* /*
* Note! This is subtle. We jump to wake people up only if * Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it). * the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/ */
static inline void up(struct semaphore * sem) static inline void up(struct semaphore * sem)
{ {
__asm__ __volatile__( __asm__ __volatile__(
"# atomic up operation\n\t" "# atomic up operation\n\t"
LOCK_PREFIX "incl %0\n\t" /* ++sem->count */ LOCK_PREFIX "incl %0\n\t" /* ++sem->count */
"jle 2f\n" "jg 1f\n\t"
"1:\n" "lea %0,%%eax\n\t"
LOCK_SECTION_START("") "call __up_wakeup\n"
"2:\tlea %0,%%eax\n\t" "1:"
"call __up_wakeup\n\t"
"jmp 1b\n"
LOCK_SECTION_END
".subsection 0\n"
:"+m" (sem->count) :"+m" (sem->count)
: :
:"memory","ax"); :"memory","ax");