From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43541C10F13 for ; Tue, 16 Apr 2019 10:04:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1128520857 for ; Tue, 16 Apr 2019 10:04:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728976AbfDPKEc (ORCPT ); Tue, 16 Apr 2019 06:04:32 -0400 Received: from terminus.zytor.com ([198.137.202.136]:55659 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726070AbfDPKEc (ORCPT ); Tue, 16 Apr 2019 06:04:32 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x3GA1nlE3397546 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 16 Apr 2019 03:01:49 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x3GA1mvX3397542; Tue, 16 Apr 2019 03:01:48 -0700 Date: Tue, 16 Apr 2019 03:01:48 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Waiman Long Message-ID: Cc: longman@redhat.com, linux-kernel@vger.kernel.org, will.deacon@arm.com, paulmck@linux.vnet.ibm.com, dave@stgolabs.net, peterz@infradead.org, torvalds@linux-foundation.org, dbueso@suse.de, bp@alien8.de, hpa@zytor.com, arnd@arndb.de, tim.c.chen@linux.intel.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@kernel.org, akpm@linux-foundation.org Reply-To: linux-kernel@vger.kernel.org, will.deacon@arm.com, paulmck@linux.vnet.ibm.com, longman@redhat.com, peterz@infradead.org, dave@stgolabs.net, dbueso@suse.de, torvalds@linux-foundation.org, tim.c.chen@linux.intel.com, a.p.zijlstra@chello.nl, hpa@zytor.com, bp@alien8.de, arnd@arndb.de, mingo@kernel.org, akpm@linux-foundation.org, tglx@linutronix.de In-Reply-To: <20190404174320.22416-3-longman@redhat.com> References: <20190404174320.22416-3-longman@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] locking/rwsem: Move owner setting code from rwsem.c to rwsem.h Git-Commit-ID: c7580c1e84435c9ccc6c612d9fee8e71811f7be6 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c7580c1e84435c9ccc6c612d9fee8e71811f7be6 Gitweb: https://git.kernel.org/tip/c7580c1e84435c9ccc6c612d9fee8e71811f7be6 Author: Waiman Long AuthorDate: Thu, 4 Apr 2019 13:43:11 -0400 Committer: Ingo Molnar CommitDate: Wed, 10 Apr 2019 10:55:59 +0200 locking/rwsem: Move owner setting code from rwsem.c to rwsem.h Move all the owner setting code closer to the rwsem-xadd fast paths directly within rwsem.h file as well as in the slowpaths where owner setting is done after acquring the lock. This will enable us to add DEBUG_RWSEMS check in a later patch to make sure that read lock is really acquired when rwsem_down_read_failed() returns, for instance. Signed-off-by: Waiman Long Acked-by: Peter Zijlstra Acked-by: Davidlohr Bueso Cc: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Davidlohr Bueso Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tim Chen Cc: Will Deacon Link: http://lkml.kernel.org/r/20190404174320.22416-3-longman@redhat.com Signed-off-by: Ingo Molnar --- kernel/locking/rwsem-xadd.c | 6 +++--- kernel/locking/rwsem.c | 19 ++----------------- kernel/locking/rwsem.h | 17 +++++++++++++++-- 3 files changed, 20 insertions(+), 22 deletions(-) diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index 0d518b52ade4..c213869e1aa7 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -176,9 +176,8 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem, goto try_reader_grant; } /* - * It is not really necessary to set it to reader-owned here, - * but it gives the spinners an early indication that the - * readers now have the lock. + * Set it to reader-owned to give spinners an early + * indication that readers now have the lock. */ __rwsem_set_reader_owned(sem, waiter->task); } @@ -441,6 +440,7 @@ __rwsem_down_read_failed_common(struct rw_semaphore *sem, int state) */ if (atomic_long_read(&sem->count) >= 0) { raw_spin_unlock_irq(&sem->wait_lock); + rwsem_set_reader_owned(sem); return sem; } adjustment += RWSEM_WAITING_BIAS; diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index e586f0d03ad3..59e584895532 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -24,7 +24,6 @@ void __sched down_read(struct rw_semaphore *sem) rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); LOCK_CONTENDED(sem, __down_read_trylock, __down_read); - rwsem_set_reader_owned(sem); } EXPORT_SYMBOL(down_read); @@ -39,7 +38,6 @@ int __sched down_read_killable(struct rw_semaphore *sem) return -EINTR; } - rwsem_set_reader_owned(sem); return 0; } @@ -52,10 +50,8 @@ int down_read_trylock(struct rw_semaphore *sem) { int ret = __down_read_trylock(sem); - if (ret == 1) { + if (ret == 1) rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_); - rwsem_set_reader_owned(sem); - } return ret; } @@ -70,7 +66,6 @@ void __sched down_write(struct rw_semaphore *sem) rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); LOCK_CONTENDED(sem, __down_write_trylock, __down_write); - rwsem_set_owner(sem); } EXPORT_SYMBOL(down_write); @@ -88,7 +83,6 @@ int __sched down_write_killable(struct rw_semaphore *sem) return -EINTR; } - rwsem_set_owner(sem); return 0; } @@ -101,10 +95,8 @@ int down_write_trylock(struct rw_semaphore *sem) { int ret = __down_write_trylock(sem); - if (ret == 1) { + if (ret == 1) rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_); - rwsem_set_owner(sem); - } return ret; } @@ -119,7 +111,6 @@ void up_read(struct rw_semaphore *sem) rwsem_release(&sem->dep_map, 1, _RET_IP_); DEBUG_RWSEMS_WARN_ON(!((unsigned long)sem->owner & RWSEM_READER_OWNED)); - rwsem_clear_reader_owned(sem); __up_read(sem); } @@ -133,7 +124,6 @@ void up_write(struct rw_semaphore *sem) rwsem_release(&sem->dep_map, 1, _RET_IP_); DEBUG_RWSEMS_WARN_ON(sem->owner != current); - rwsem_clear_owner(sem); __up_write(sem); } @@ -147,7 +137,6 @@ void downgrade_write(struct rw_semaphore *sem) lock_downgrade(&sem->dep_map, _RET_IP_); DEBUG_RWSEMS_WARN_ON(sem->owner != current); - rwsem_set_reader_owned(sem); __downgrade_write(sem); } @@ -161,7 +150,6 @@ void down_read_nested(struct rw_semaphore *sem, int subclass) rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_); LOCK_CONTENDED(sem, __down_read_trylock, __down_read); - rwsem_set_reader_owned(sem); } EXPORT_SYMBOL(down_read_nested); @@ -172,7 +160,6 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) rwsem_acquire_nest(&sem->dep_map, 0, 0, nest, _RET_IP_); LOCK_CONTENDED(sem, __down_write_trylock, __down_write); - rwsem_set_owner(sem); } EXPORT_SYMBOL(_down_write_nest_lock); @@ -193,7 +180,6 @@ void down_write_nested(struct rw_semaphore *sem, int subclass) rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_); LOCK_CONTENDED(sem, __down_write_trylock, __down_write); - rwsem_set_owner(sem); } EXPORT_SYMBOL(down_write_nested); @@ -208,7 +194,6 @@ int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass) return -EINTR; } - rwsem_set_owner(sem); return 0; } diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h index 1f5775aa6a1d..ee24c4f257a5 100644 --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -160,6 +160,8 @@ static inline void __down_read(struct rw_semaphore *sem) { if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) rwsem_down_read_failed(sem); + else + rwsem_set_reader_owned(sem); } static inline int __down_read_killable(struct rw_semaphore *sem) @@ -167,8 +169,9 @@ 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; + } else { + rwsem_set_reader_owned(sem); } - return 0; } @@ -182,6 +185,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) do { if (atomic_long_try_cmpxchg_acquire(&sem->count, &tmp, tmp + RWSEM_ACTIVE_READ_BIAS)) { + rwsem_set_reader_owned(sem); return 1; } } while (tmp >= 0); @@ -199,6 +203,7 @@ static inline void __down_write(struct rw_semaphore *sem) &sem->count); if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) rwsem_down_write_failed(sem); + rwsem_set_owner(sem); } static inline int __down_write_killable(struct rw_semaphore *sem) @@ -210,6 +215,7 @@ static inline int __down_write_killable(struct rw_semaphore *sem) if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) if (IS_ERR(rwsem_down_write_failed_killable(sem))) return -EINTR; + rwsem_set_owner(sem); return 0; } @@ -219,7 +225,11 @@ static inline int __down_write_trylock(struct rw_semaphore *sem) tmp = atomic_long_cmpxchg_acquire(&sem->count, RWSEM_UNLOCKED_VALUE, RWSEM_ACTIVE_WRITE_BIAS); - return tmp == RWSEM_UNLOCKED_VALUE; + if (tmp == RWSEM_UNLOCKED_VALUE) { + rwsem_set_owner(sem); + return true; + } + return false; } /* @@ -229,6 +239,7 @@ static inline void __up_read(struct rw_semaphore *sem) { long tmp; + rwsem_clear_reader_owned(sem); tmp = atomic_long_dec_return_release(&sem->count); if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)) rwsem_wake(sem); @@ -239,6 +250,7 @@ static inline void __up_read(struct rw_semaphore *sem) */ static inline void __up_write(struct rw_semaphore *sem) { + rwsem_clear_owner(sem); if (unlikely(atomic_long_sub_return_release(RWSEM_ACTIVE_WRITE_BIAS, &sem->count) < 0)) rwsem_wake(sem); @@ -259,6 +271,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem) * write side. As such, rely on RELEASE semantics. */ tmp = atomic_long_add_return_release(-RWSEM_WAITING_BIAS, &sem->count); + rwsem_set_reader_owned(sem); if (tmp < 0) rwsem_downgrade_wake(sem); }