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=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,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 C2AC9C4167B for ; Wed, 9 Dec 2020 18:40:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 789E423C85 for ; Wed, 9 Dec 2020 18:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732934AbgLISkX (ORCPT ); Wed, 9 Dec 2020 13:40:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733214AbgLISkJ (ORCPT ); Wed, 9 Dec 2020 13:40:09 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37ECFC0617A6; Wed, 9 Dec 2020 10:38:52 -0800 (PST) Date: Wed, 09 Dec 2020 18:38:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1607539129; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0y3sceUgBRhZYZVpiBwCuyuF9u3CjWj1N+sKMh5dPcU=; b=PgEMM9Ma4YkuhJUD80T4S5loKR5ENnXpzi/D5JTP7pny+3KTgsSareXrm870R02RR9qT95 jVjm4OmkliYdjRB0aVyiXrr1t+Zj+C8ZGmEfjl5Fkxj1JCYhHriZN1VyC+Agq7eS2deDtn 2FBk8ObmvEXFC9dDIQHWxVXatzLlvzyonQce0bULAjzr4Z8EUx3bZOh6q+PTqLwMq4dP2W hI3o6nPugiI4t674mNaaoIEwjj6a98KygMgnyTahkF2bY6JQCqJ3IjiRL14liz4COPoCB+ CKAHho+LvL9XWm6dquHA/NypX/sBCUUYlxWpDprfV/bnSvBJEX7YWnB5z32+hg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1607539129; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0y3sceUgBRhZYZVpiBwCuyuF9u3CjWj1N+sKMh5dPcU=; b=WQZPUqHAd5gMiRkRg9I4vfQb+CEn5bKR7lRszxl2MOmx3GeCzZJW9fW2xbQB6ceBmME3cX OlrdptxkRS/rceCQ== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: locking/core] locking/rwsem: Better collate rwsem_read_trylock() Cc: "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20201207090243.GE3040@hirez.programming.kicks-ass.net> References: <20201207090243.GE3040@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Message-ID: <160753912872.3364.17787139748341246196.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the locking/core branch of tip: Commit-ID: 3379116a0ca965b00e6522c7ea3f16c9dbd8f9f9 Gitweb: https://git.kernel.org/tip/3379116a0ca965b00e6522c7ea3f16c9dbd8f9f9 Author: Peter Zijlstra AuthorDate: Tue, 08 Dec 2020 10:22:16 +01:00 Committer: Peter Zijlstra CommitterDate: Wed, 09 Dec 2020 17:08:47 +01:00 locking/rwsem: Better collate rwsem_read_trylock() All users of rwsem_read_trylock() do rwsem_set_reader_owned(sem) on success, move it into rwsem_read_trylock() proper. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net --- kernel/locking/rwsem.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index a163542..5c0dc7e 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -273,9 +273,16 @@ static inline void rwsem_set_nonspinnable(struct rw_semaphore *sem) static inline bool rwsem_read_trylock(struct rw_semaphore *sem) { long cnt = atomic_long_add_return_acquire(RWSEM_READER_BIAS, &sem->count); + if (WARN_ON_ONCE(cnt < 0)) rwsem_set_nonspinnable(sem); - return !(cnt & RWSEM_READ_FAILED_MASK); + + if (!(cnt & RWSEM_READ_FAILED_MASK)) { + rwsem_set_reader_owned(sem); + return true; + } + + return false; } /* @@ -1340,8 +1347,6 @@ static inline void __down_read(struct rw_semaphore *sem) if (!rwsem_read_trylock(sem)) { rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE); DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); - } else { - rwsem_set_reader_owned(sem); } } @@ -1351,8 +1356,6 @@ static inline int __down_read_interruptible(struct rw_semaphore *sem) if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE))) return -EINTR; DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); - } else { - rwsem_set_reader_owned(sem); } return 0; } @@ -1363,8 +1366,6 @@ static inline int __down_read_killable(struct rw_semaphore *sem) if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_KILLABLE))) return -EINTR; DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); - } else { - rwsem_set_reader_owned(sem); } return 0; }