[PATCH] add sem_is_read/write_locked()

Add sem_is_read/write_locked functions to the read/write semaphores, along the
same lines of the *_is_locked spinlock functions.  The swap token tuning patch
uses sem_is_read_locked; sem_is_write_locked is added for completeness.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/asm-ppc64/rwsem.h b/include/asm-ppc64/rwsem.h
index bd5c2f093575..7a647fae3765 100644
--- a/include/asm-ppc64/rwsem.h
+++ b/include/asm-ppc64/rwsem.h
@@ -163,5 +163,10 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
         return atomic_add_return(delta, (atomic_t *)(&sem->count));
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+        return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _PPC_RWSEM_XADD_H */