[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-ia64/rwsem.h b/include/asm-ia64/rwsem.h
index e18b5ab0cb75..1327c91ea39c 100644
--- a/include/asm-ia64/rwsem.h
+++ b/include/asm-ia64/rwsem.h
@@ -186,4 +186,9 @@ __downgrade_write (struct rw_semaphore *sem)
 #define rwsem_atomic_add(delta, sem)    atomic64_add(delta, (atomic64_t *)(&(sem)->count))
 #define rwsem_atomic_update(delta, sem) atomic64_add_return(delta, (atomic64_t *)(&(sem)->count))
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+        return (sem->count != 0);
+}
+
 #endif /* _ASM_IA64_RWSEM_H */