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authorNick Piggin <npiggin@suse.de>2007-10-18 03:06:54 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-18 14:37:29 -0700
commitb8dc93cbe91324b922395919cd5df4cca2fe55f6 (patch)
tree724a8813d6b5119619a6b8c499a59825575ae0c9
parent66ffb04ca5ec43ca763e8a9802ca3244f5519ae1 (diff)
downloadop-kernel-dev-b8dc93cbe91324b922395919cd5df4cca2fe55f6.zip
op-kernel-dev-b8dc93cbe91324b922395919cd5df4cca2fe55f6.tar.gz
bit_spin_lock: use lock bitops
Convert bit_spin_lock to new locking bitops. Slub can use the non-atomic store version to clear (Christoph?) Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/bit_spinlock.h26
1 files changed, 22 insertions, 4 deletions
diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h
index 6b20af0..7113a32 100644
--- a/include/linux/bit_spinlock.h
+++ b/include/linux/bit_spinlock.h
@@ -18,7 +18,7 @@ static inline void bit_spin_lock(int bitnum, unsigned long *addr)
*/
preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- while (test_and_set_bit(bitnum, addr)) {
+ while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
while (test_bit(bitnum, addr)) {
preempt_enable();
cpu_relax();
@@ -36,7 +36,7 @@ static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
{
preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- if (test_and_set_bit(bitnum, addr)) {
+ if (unlikely(test_and_set_bit_lock(bitnum, addr))) {
preempt_enable();
return 0;
}
@@ -50,10 +50,28 @@ static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
*/
static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
{
+#ifdef CONFIG_DEBUG_SPINLOCK
+ BUG_ON(!test_bit(bitnum, addr));
+#endif
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+ clear_bit_unlock(bitnum, addr);
+#endif
+ preempt_enable();
+ __release(bitlock);
+}
+
+/*
+ * bit-based spin_unlock()
+ * non-atomic version, which can be used eg. if the bit lock itself is
+ * protecting the rest of the flags in the word.
+ */
+static inline void __bit_spin_unlock(int bitnum, unsigned long *addr)
+{
+#ifdef CONFIG_DEBUG_SPINLOCK
BUG_ON(!test_bit(bitnum, addr));
- smp_mb__before_clear_bit();
- clear_bit(bitnum, addr);
+#endif
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+ __clear_bit_unlock(bitnum, addr);
#endif
preempt_enable();
__release(bitlock);
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