diff options
Diffstat (limited to 'include/linux/rwsem.h')
| -rw-r--r-- | include/linux/rwsem.h | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 03f3b05e8ec1..035d3c57fc8a 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -13,8 +13,10 @@ #include <linux/kernel.h> #include <linux/list.h> #include <linux/spinlock.h> - #include <linux/atomic.h> +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER +#include <linux/osq_lock.h> +#endif struct rw_semaphore; @@ -23,9 +25,17 @@ 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; + struct list_head wait_list; + raw_spinlock_t wait_lock; +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER + struct optimistic_spin_queue osq; /* spinner MCS lock */ + /* + * Write owner. Used as a speculative check to see + * if the owner is running on the cpu. + */ + struct task_struct *owner; +#endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif @@ -55,10 +65,17 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) # define __RWSEM_DEP_MAP_INIT(lockname) #endif -#define __RWSEM_INITIALIZER(name) \ - { RWSEM_UNLOCKED_VALUE, \ - __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ - LIST_HEAD_INIT((name).wait_list) \ +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER +#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL +#else +#define __RWSEM_OPT_INIT(lockname) +#endif + +#define __RWSEM_INITIALIZER(name) \ + { .count = RWSEM_UNLOCKED_VALUE, \ + .wait_list = LIST_HEAD_INIT((name).wait_list), \ + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock) \ + __RWSEM_OPT_INIT(name) \ __RWSEM_DEP_MAP_INIT(name) } #define DECLARE_RWSEM(name) \ |