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authorDavidlohr Bueso <davidlohr@hp.com>2014-07-12 01:00:06 +0400
committerIngo Molnar <mingo@kernel.org>2014-07-16 16:57:13 +0400
commit5db6c6fefb1ca0e81e3bd6dd8998bf51c453d823 (patch)
treedde571797891c57f73656cbbde9bc950831ef6a0 /include/linux/rwsem.h
parent4badad352a6bb202ec68afa7a574c0bb961e5ebc (diff)
downloadlinux-5db6c6fefb1ca0e81e3bd6dd8998bf51c453d823.tar.xz
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/linux/rwsem.h')
-rw-r--r--include/linux/rwsem.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 716807f0eb2d..035d3c57fc8a 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)