[RFC 11/12] x86, rwsem: provide __down_write_killable
From: Michal Hocko <mhocko@kernel.org>
Date: 2016-02-02 20:20:26
Also in:
linux-arch, linux-s390, linux-sh, lkml, sparclinux
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Michal Hocko <mhocko@suse.com> 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@suse.com> --- 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