From: Michal Hocko <mhocko@xxxxxxxx>
which is 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@xxxxxxxx>
---
arch/x86/include/asm/rwsem.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index 1b5e89b3643d..64899daa51e2 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -109,6 +109,19 @@ static inline void __down_write(struct rw_semaphore *sem)
rwsem_down_write_failed(sem);
}
+static inline int __down_write_killable(struct rw_semaphore *sem)
+{
+ long tmp;
+
+ tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS,
+ (atomic_long_t *)&sem->count);
+ if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))
+ if (IS_ERR(rwsem_down_write_failed_killable(sem)))
+ return -EINTR;
+
+ return 0;
+}
+
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
--
2.7.0
--
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