diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/rwsem.h | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 03f3b05e8ec1..8d79708146aa 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -16,6 +16,7 @@ #include <linux/atomic.h> +struct optimistic_spin_queue; struct rw_semaphore; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK @@ -23,9 +24,17 @@ struct rw_semaphore; #else /* All arch specific implementations share the same struct */ struct rw_semaphore { - long count; - raw_spinlock_t wait_lock; - struct list_head wait_list; + long count; + raw_spinlock_t wait_lock; + struct list_head wait_list; +#ifdef CONFIG_SMP + /* + * Write owner. Used as a speculative check to see + * if the owner is running on the cpu. + */ + struct task_struct *owner; + struct optimistic_spin_queue *osq; /* spinner MCS lock */ +#endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif @@ -55,11 +64,21 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) # define __RWSEM_DEP_MAP_INIT(lockname) #endif +#if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) +#define __RWSEM_INITIALIZER(name) \ + { RWSEM_UNLOCKED_VALUE, \ + __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ + LIST_HEAD_INIT((name).wait_list), \ + NULL, /* owner */ \ + NULL /* mcs lock */ \ + __RWSEM_DEP_MAP_INIT(name) } +#else #define __RWSEM_INITIALIZER(name) \ { RWSEM_UNLOCKED_VALUE, \ __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ LIST_HEAD_INIT((name).wait_list) \ __RWSEM_DEP_MAP_INIT(name) } +#endif #define DECLARE_RWSEM(name) \ struct rw_semaphore name = __RWSEM_INITIALIZER(name) |