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authorAndi Kleen <ak@suse.de>2006-09-26 10:52:32 +0200
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 10:52:32 +0200
commit8578bdf835d6d6ece6718858d351456367b8a5cf (patch)
tree5bf4aa72bda1f5c508d955a2d32b5d292f8bd5a7
parent7ca2b49b06a6d26e89e3535653889f1d7892b085 (diff)
downloadblackbird-op-linux-8578bdf835d6d6ece6718858d351456367b8a5cf.tar.gz
blackbird-op-linux-8578bdf835d6d6ece6718858d351456367b8a5cf.zip
[PATCH] Don't use lock section for mutexes and semaphores
Lock sections cannot be handled by the dwarf2 unwinder. Disadvantage is a taken branch in the hot path. Signed-off-by: Andi Kleen <ak@suse.de>
-rw-r--r--include/asm-x86_64/mutex.h20
-rw-r--r--include/asm-x86_64/semaphore.h40
-rw-r--r--include/asm-x86_64/spinlock.h9
3 files changed, 24 insertions, 45 deletions
diff --git a/include/asm-x86_64/mutex.h b/include/asm-x86_64/mutex.h
index 06fab6de2a88..16396b1de3e4 100644
--- a/include/asm-x86_64/mutex.h
+++ b/include/asm-x86_64/mutex.h
@@ -25,13 +25,9 @@ do { \
\
__asm__ __volatile__( \
LOCK_PREFIX " decl (%%rdi) \n" \
- " js 2f \n" \
- "1: \n" \
- \
- LOCK_SECTION_START("") \
- "2: call "#fail_fn" \n" \
- " jmp 1b \n" \
- LOCK_SECTION_END \
+ " jns 1f \n" \
+ " call "#fail_fn" \n" \
+ "1:" \
\
:"=D" (dummy) \
: "D" (v) \
@@ -75,13 +71,9 @@ do { \
\
__asm__ __volatile__( \
LOCK_PREFIX " incl (%%rdi) \n" \
- " jle 2f \n" \
- "1: \n" \
- \
- LOCK_SECTION_START("") \
- "2: call "#fail_fn" \n" \
- " jmp 1b \n" \
- LOCK_SECTION_END \
+ " jg 1f \n" \
+ " call "#fail_fn" \n" \
+ "1: " \
\
:"=D" (dummy) \
: "D" (v) \
diff --git a/include/asm-x86_64/semaphore.h b/include/asm-x86_64/semaphore.h
index 064df08b9a0f..107bd90429e8 100644
--- a/include/asm-x86_64/semaphore.h
+++ b/include/asm-x86_64/semaphore.h
@@ -107,12 +107,9 @@ static inline void down(struct semaphore * sem)
__asm__ __volatile__(
"# atomic down operation\n\t"
LOCK_PREFIX "decl %0\n\t" /* --sem->count */
- "js 2f\n"
- "1:\n"
- LOCK_SECTION_START("")
- "2:\tcall __down_failed\n\t"
- "jmp 1b\n"
- LOCK_SECTION_END
+ "jns 1f\n\t"
+ "call __down_failed\n"
+ "1:"
:"=m" (sem->count)
:"D" (sem)
:"memory");
@@ -130,14 +127,11 @@ static inline int down_interruptible(struct semaphore * sem)
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
+ "xorl %0,%0\n\t"
LOCK_PREFIX "decl %1\n\t" /* --sem->count */
- "js 2f\n\t"
- "xorl %0,%0\n"
- "1:\n"
- LOCK_SECTION_START("")
- "2:\tcall __down_failed_interruptible\n\t"
- "jmp 1b\n"
- LOCK_SECTION_END
+ "jns 2f\n\t"
+ "call __down_failed_interruptible\n"
+ "2:\n"
:"=a" (result), "=m" (sem->count)
:"D" (sem)
:"memory");
@@ -154,14 +148,11 @@ static inline int down_trylock(struct semaphore * sem)
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
+ "xorl %0,%0\n\t"
LOCK_PREFIX "decl %1\n\t" /* --sem->count */
- "js 2f\n\t"
- "xorl %0,%0\n"
- "1:\n"
- LOCK_SECTION_START("")
- "2:\tcall __down_failed_trylock\n\t"
- "jmp 1b\n"
- LOCK_SECTION_END
+ "jns 2f\n\t"
+ "call __down_failed_trylock\n\t"
+ "2:\n"
:"=a" (result), "=m" (sem->count)
:"D" (sem)
:"memory","cc");
@@ -179,12 +170,9 @@ static inline void up(struct semaphore * sem)
__asm__ __volatile__(
"# atomic up operation\n\t"
LOCK_PREFIX "incl %0\n\t" /* ++sem->count */
- "jle 2f\n"
- "1:\n"
- LOCK_SECTION_START("")
- "2:\tcall __up_wakeup\n\t"
- "jmp 1b\n"
- LOCK_SECTION_END
+ "jg 1f\n\t"
+ "call __up_wakeup\n"
+ "1:"
:"=m" (sem->count)
:"D" (sem)
:"memory");
diff --git a/include/asm-x86_64/spinlock.h b/include/asm-x86_64/spinlock.h
index a8e3d89f591f..1d0733b38a4b 100644
--- a/include/asm-x86_64/spinlock.h
+++ b/include/asm-x86_64/spinlock.h
@@ -22,14 +22,13 @@
#define __raw_spin_lock_string \
"\n1:\t" \
LOCK_PREFIX " ; decl %0\n\t" \
- "js 2f\n" \
- LOCK_SECTION_START("") \
- "2:\t" \
+ "jns 2f\n" \
+ "3:\n" \
"rep;nop\n\t" \
"cmpl $0,%0\n\t" \
- "jle 2b\n\t" \
+ "jle 3b\n\t" \
"jmp 1b\n" \
- LOCK_SECTION_END
+ "2:\t" \
#define __raw_spin_lock_string_up \
"\n\tdecl %0"
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