diff options
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 01f71e1d2e94..7ac6bf4922a5 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -1161,5 +1161,17 @@ do { \ ftrace_dump(oops_dump_mode); \ } while (0) +/* + * Place this after a lock-acquisition primitive to guarantee that + * an UNLOCK+LOCK pair acts as a full barrier. This guarantee applies + * if the UNLOCK and LOCK are executed by the same CPU or if the + * UNLOCK and LOCK operate on the same lock variable. + */ +#ifdef CONFIG_ARCH_WEAK_RELEASE_ACQUIRE +#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */ +#else /* #ifdef CONFIG_ARCH_WEAK_RELEASE_ACQUIRE */ +#define smp_mb__after_unlock_lock() do { } while (0) +#endif /* #else #ifdef CONFIG_ARCH_WEAK_RELEASE_ACQUIRE */ + #endif /* __LINUX_RCUPDATE_H */ |