diff options
Diffstat (limited to 'kernel/include/asm-generic/bitops/lock.h')
| -rw-r--r-- | kernel/include/asm-generic/bitops/lock.h | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/include/asm-generic/bitops/lock.h b/kernel/include/asm-generic/bitops/lock.h index c30266e94..8ef0ccbf8 100644 --- a/kernel/include/asm-generic/bitops/lock.h +++ b/kernel/include/asm-generic/bitops/lock.h @@ -29,16 +29,16 @@ do { \ * @nr: the bit to set * @addr: the address to start counting from * - * This operation is like clear_bit_unlock, however it is not atomic. - * It does provide release barrier semantics so it can be used to unlock - * a bit lock, however it would only be used if no other CPU can modify - * any bits in the memory until the lock is released (a good example is - * if the bit lock itself protects access to the other bits in the word). + * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all + * the bits in the word are protected by this lock some archs can use weaker + * ops to safely unlock. + * + * See for example x86's implementation. */ #define __clear_bit_unlock(nr, addr) \ do { \ - smp_mb(); \ - __clear_bit(nr, addr); \ + smp_mb__before_atomic(); \ + clear_bit(nr, addr); \ } while (0) #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ |