From d47996082f52baa0ca8b48d26b3cbef5ede70a73 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 7 Apr 2016 17:12:26 +0200 Subject: locking/rwsem: Introduce basis for down_write_killable() Introduce a generic implementation necessary for down_write_killable(). This is a trivial extension of the already existing down_write() call which can be interrupted by SIGKILL. This patch doesn't provide down_write_killable() yet because arches have to provide the necessary pieces before. rwsem_down_write_failed() which is a generic slow path for the write lock is extended to take a task state and renamed to __rwsem_down_write_failed_common(). The return value is either a valid semaphore pointer or ERR_PTR(-EINTR). rwsem_down_write_failed_killable() is exported as a new way to wait for the lock and be killable. For rwsem-spinlock implementation the current __down_write() it updated in a similar way as __rwsem_down_write_failed_common() except it doesn't need new exports just visible __down_write_killable(). Architectures which are not using the generic rwsem implementation are supposed to provide their __down_write_killable() implementation and use rwsem_down_write_failed_killable() for the slow path. Signed-off-by: Michal Hocko Cc: Andrew Morton Cc: Chris Zankel Cc: David S. Miller Cc: Linus Torvalds Cc: Max Filippov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Signed-off-by: Davidlohr Bueso Cc: Signed-off-by: Jason Low Cc: Thomas Gleixner Cc: Tony Luck Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/1460041951-22347-7-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar --- include/linux/rwsem-spinlock.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/rwsem-spinlock.h') diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h index a733a5467e6c..ae0528b834cd 100644 --- a/include/linux/rwsem-spinlock.h +++ b/include/linux/rwsem-spinlock.h @@ -34,6 +34,7 @@ struct rw_semaphore { extern void __down_read(struct rw_semaphore *sem); extern int __down_read_trylock(struct rw_semaphore *sem); extern void __down_write(struct rw_semaphore *sem); +extern int __must_check __down_write_killable(struct rw_semaphore *sem); extern int __down_write_trylock(struct rw_semaphore *sem); extern void __up_read(struct rw_semaphore *sem); extern void __up_write(struct rw_semaphore *sem); -- cgit v1.2.3-55-g7522