From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756525AbdJJLJA (ORCPT ); Tue, 10 Oct 2017 07:09:00 -0400 Received: from terminus.zytor.com ([65.50.211.136]:33627 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756185AbdJJLI6 (ORCPT ); Tue, 10 Oct 2017 07:08:58 -0400 Date: Tue, 10 Oct 2017 04:05:31 -0700 From: tip-bot for Kirill Tkhai Message-ID: Cc: hpa@zytor.com, peterz@infradead.org, torvalds@linux-foundation.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, ktkhai@virtuozzo.com Reply-To: ktkhai@virtuozzo.com, linux-kernel@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, hpa@zytor.com In-Reply-To: <150670119884.23930.2585570605960763239.stgit@localhost.localdomain> References: <150670119884.23930.2585570605960763239.stgit@localhost.localdomain> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] locking/rwsem: Add down_read_killable() Git-Commit-ID: 76f8507f7a6442215df19de74f07eabca2462f1e X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 76f8507f7a6442215df19de74f07eabca2462f1e Gitweb: https://git.kernel.org/tip/76f8507f7a6442215df19de74f07eabca2462f1e Author: Kirill Tkhai AuthorDate: Fri, 29 Sep 2017 19:06:38 +0300 Committer: Ingo Molnar CommitDate: Tue, 10 Oct 2017 11:50:16 +0200 locking/rwsem: Add down_read_killable() 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 Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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 --- include/asm-generic/rwsem.h | 10 ++++++++++ include/linux/rwsem.h | 1 + kernel/locking/rwsem.c | 16 ++++++++++++++++ 3 files changed, 27 insertions(+) diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h index 6c6a214..b2d68d2 100644 --- a/include/asm-generic/rwsem.h +++ b/include/asm-generic/rwsem.h @@ -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; diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 0ad7318..6ac8ee5 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -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 diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 4d48b1c..e53f7746 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -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 */