diff options
| author | Davidlohr Bueso <davidlohr@hp.com> | 2014-07-11 14:00:06 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-07-16 14:57:13 +0200 |
| commit | 5db6c6fefb1ca0e81e3bd6dd8998bf51c453d823 (patch) | |
| tree | dde571797891c57f73656cbbde9bc950831ef6a0 /include | |
| parent | 4badad352a6bb202ec68afa7a574c0bb961e5ebc (diff) | |
locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER
Just like with mutexes (CONFIG_MUTEX_SPIN_ON_OWNER),
encapsulate the dependencies for rwsem optimistic spinning.
No logical changes here as it continues to depend on both
SMP and the XADD algorithm variant.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Jason Low <jason.low2@hp.com>
[ Also make it depend on ARCH_SUPPORTS_ATOMIC_RMW. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1405112406-13052-2-git-send-email-davidlohr@hp.com
Cc: aswin@hp.com
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rwsem.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 716807f0eb2..035d3c57fc8 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -14,7 +14,9 @@ #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; @@ -26,7 +28,7 @@ struct rw_semaphore { long count; struct list_head wait_list; raw_spinlock_t wait_lock; -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER struct optimistic_spin_queue osq; /* spinner MCS lock */ /* * Write owner. Used as a speculative check to see @@ -63,7 +65,7 @@ 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) +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER #define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL #else #define __RWSEM_OPT_INIT(lockname) |