diff options
| author | Linus Torvalds | 2014-06-12 18:48:15 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2014-06-12 18:48:15 -0700 |
| commit | c29deef32e3699e40da3e9e82267610de04e6b54 (patch) | |
| tree | 820ab21fe399225f7341499e461ee793a180d414 /include/linux | |
| parent | f9da455b93f6ba076935b4ef4589f61e529ae046 (diff) | |
| parent | bd01ec1a13f9a327950c8e3080096446c7804753 (diff) | |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more locking changes from Ingo Molnar:
"This is the second round of locking tree updates for v3.16, offering
large system scalability improvements:
- optimistic spinning for rwsems, from Davidlohr Bueso.
- 'qrwlocks' core code and x86 enablement, from Waiman Long and PeterZ"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, locking/rwlocks: Enable qrwlocks on x86
locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks
locking/mutexes: Documentation update/rewrite
locking/rwsem: Fix checkpatch.pl warnings
locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK
locking/rwsem: Support optimistic spinning
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) |