locking/rwsem: Add down_read_killable() (76f8507f) · Commits · 戴 / test

Similar to down_read() and down_write_killable(), add killable version of down_read(), based on __down_read_killable() function, added in previous patches. Signed-off-by:

Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670119884.23930.2585570605960763239.stgit@localhost.localdomain Signed-off-by:

Ingo Molnar <mingo@kernel.org>

include/asm-generic/rwsem.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -37,6 +37,16 @@ static inline void __down_read(struct rw_semaphore *sem)
		rwsem_down_read_failed(sem);
		}

		static inline int __down_read_killable(struct rw_semaphore *sem)
		{
		if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) {
		if (IS_ERR(rwsem_down_read_failed_killable(sem)))
		return -EINTR;
		}

		return 0;
		}

		static inline int __down_read_trylock(struct rw_semaphore *sem)
		{
		long tmp;

include/linux/rwsem.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -111,6 +111,7 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem)
		* lock for reading
		*/
		extern void down_read(struct rw_semaphore *sem);
		extern int __must_check down_read_killable(struct rw_semaphore *sem);

		/*
		* trylock for reading -- returns 1 if successful, 0 if contention

kernel/locking/rwsem.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,22 @@ void __sched down_read(struct rw_semaphore *sem)

		EXPORT_SYMBOL(down_read);

		int __sched down_read_killable(struct rw_semaphore *sem)
		{
		might_sleep();
		rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);

		if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_killable)) {
		rwsem_release(&sem->dep_map, 1, _RET_IP_);
		return -EINTR;
		}

		rwsem_set_reader_owned(sem);
		return 0;
		}

		EXPORT_SYMBOL(down_read_killable);

		/*
		* trylock for reading -- returns 1 if successful, 0 if contention
		*/

Admin message