[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>
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h
index b52a2af..f30f805 100644
--- a/include/linux/rwsem-spinlock.h
+++ b/include/linux/rwsem-spinlock.h
@@ -61,5 +61,10 @@
extern void FASTCALL(__up_write(struct rw_semaphore *sem));
extern void FASTCALL(__downgrade_write(struct rw_semaphore *sem));
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+ return (sem->activity != 0);
+}
+
#endif /* __KERNEL__ */
#endif /* _LINUX_RWSEM_SPINLOCK_H */