[PATCH 07/11] sh, rwsem: provide __down_write_killable

Michal Hocko
2016-02-29T12:58:21Z

From: Michal Hocko <mhocko@suse.com>

which uses the same fast path as __down_write except it falls back to
rwsem_down_write_failed_killable slow path and return -EINTR if killed.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
arch/sh/include/asm/rwsem.h | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/arch/sh/include/asm/rwsem.h b/arch/sh/include/asm/rwsem.h
index f6c951c7a875..8a457b83d2a5 100644
--- a/arch/sh/include/asm/rwsem.h
+++ b/arch/sh/include/asm/rwsem.h
@@ -54,6 +54,19 @@ static inline void __down_write(struct rw_semaphore *sem)
rwsem_down_write_failed(sem);
}

+static inline int __down_write_killable(struct rw_semaphore *sem)
+{
+ int tmp;
+
+ tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
+ (atomic_t *)(&sem->count));
+ if (tmp != RWSEM_ACTIVE_WRITE_BIAS)
+ if (IS_ERR(rwsem_down_write_failed_killable(sem)))
+ return -EINTR;
+
+ return 0;
+}
+
static inline int __down_write_trylock(struct rw_semaphore *sem)
{
int tmp;
--
2.7.0