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authorJason Low <jason.low2@hp.com>2014-07-14 10:27:50 -0700
committerIngo Molnar <mingo@kernel.org>2014-07-16 13:28:05 +0200
commit4d9d951e6b5df85ccfca2c5bd8b4f5c71d256b65 (patch)
tree451c3e6656bb75fa42baa97d344db38bdab7f4ab
parentlocking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead (diff)
downloadlinux-dev-4d9d951e6b5df85ccfca2c5bd8b4f5c71d256b65.tar.xz
linux-dev-4d9d951e6b5df85ccfca2c5bd8b4f5c71d256b65.zip
locking/spinlocks/mcs: Introduce and use init macro and function for osq locks
Currently, we initialize the osq lock by directly setting the lock's values. It would be preferable if we use an init macro to do the initialization like we do with other locks. This patch introduces and uses a macro and function for initializing the osq lock. Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Scott Norton <scott.norton@hp.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fusionio.com> Link: http://lkml.kernel.org/r/1405358872-3732-4-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--include/linux/osq_lock.h8
-rw-r--r--include/linux/rwsem.h2
-rw-r--r--kernel/locking/mutex.c2
-rw-r--r--kernel/locking/rwsem-xadd.c2
4 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index b001682bf7cb..90230d5811c5 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -16,4 +16,12 @@ struct optimistic_spin_queue {
atomic_t tail;
};
+/* Init macro and function. */
+#define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
+
+static inline void osq_lock_init(struct optimistic_spin_queue *lock)
+{
+ atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
+}
+
#endif
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 9fdcdd03507d..25cd9aa2f3d7 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -69,7 +69,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
__RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
LIST_HEAD_INIT((name).wait_list), \
NULL, /* owner */ \
- { ATOMIC_INIT(OSQ_UNLOCKED_VAL) } /* osq */ \
+ OSQ_LOCK_UNLOCKED /* osq */ \
__RWSEM_DEP_MAP_INIT(name) }
#else
#define __RWSEM_INITIALIZER(name) \
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index d9b313906caa..acca2c1a3c5e 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -60,7 +60,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
INIT_LIST_HEAD(&lock->wait_list);
mutex_clear_owner(lock);
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
- atomic_set(&lock->osq.tail, OSQ_UNLOCKED_VAL);
+ osq_lock_init(&lock->osq);
#endif
debug_mutex_init(lock, name, key);
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index b77a6230bbf6..7190592c2645 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -84,7 +84,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
INIT_LIST_HEAD(&sem->wait_list);
#ifdef CONFIG_SMP
sem->owner = NULL;
- atomic_set(&sem->osq.tail, OSQ_UNLOCKED_VAL);
+ osq_lock_init(&sem->osq);
#endif
}