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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 6D9BDC48BDF for ; Fri, 18 Jun 2021 14:56:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5137961369 for ; Fri, 18 Jun 2021 14:56:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234802AbhFRO6K (ORCPT ); Fri, 18 Jun 2021 10:58:10 -0400 Received: from pv50p00im-ztdg10021101.me.com ([17.58.6.44]:53722 "EHLO pv50p00im-ztdg10021101.me.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234791AbhFRO6J (ORCPT ); Fri, 18 Jun 2021 10:58:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=me.com; s=1a1hai; t=1624028160; bh=1JIjVblmIBwSMEEZ+LXUVg56tLYtzwLVT259Gir4bfY=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=XYRKV+RhhdpiCv91uaxEc4ic2wVRjPPwL/XGJaAOpaiUen1S8N27OsqBhI0u3le8R mH85tc3Nma8l7GSW19nOlJHuYr0ZSkY/EZ2em4swZTSg7CloGuHixvaSKFDS8suLnr tHzk2kaS/JLOMRl0Gk69LH/qqGY5wHjUkeyalqVfvKHtkf54tiryLBNtOC2st7Jxc6 mTyIfgO5KJvoSJh+U7eVLqc4WoEd87WFwg0EaPaEBXxC6iI0Hf1IhXDOWpQlw4caUL Cex/iCCbCP8FBF6Tjx497kM8S1a0HCFN4LriorzKHIgNu1nJ/DktRoCkz34hxzd7RP +J/GueD2KZrbQ== Received: from xiongwei.. (unknown [120.245.2.120]) by pv50p00im-ztdg10021101.me.com (Postfix) with ESMTPSA id 161B1180384; Fri, 18 Jun 2021 14:55:56 +0000 (UTC) From: Xiongwei Song To: peterz@infradead.org, mingo@redhat.com, will@kernel.org, longman@redhat.com, boqun.feng@gmail.com Cc: linux-kernel@vger.kernel.org, Xiongwei Song Subject: [PATCH v2 1/3] locking/lockdep: Unlikely bfs_error() inside Date: Fri, 18 Jun 2021 22:55:32 +0800 Message-Id: <20210618145534.438816-2-sxwjean@me.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210618145534.438816-1-sxwjean@me.com> References: <20210618145534.438816-1-sxwjean@me.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-06-18_07:2021-06-18,2021-06-18 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-2009150000 definitions=main-2106180088 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiongwei Song The error from graph walk is small probability event, and there are some bfs_error calls during lockdep detection, so unlikely bfs_error inside can improve performance a little bit. Suggested-by: Waiman Long Signed-off-by: Xiongwei Song --- kernel/locking/lockdep.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 7641bd407239..a8a66a2a9bc1 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1540,7 +1540,7 @@ enum bfs_result { */ static inline bool bfs_error(enum bfs_result res) { - return res < 0; + return unlikely(res < 0); } /* @@ -2089,7 +2089,7 @@ check_path(struct held_lock *target, struct lock_list *src_entry, ret = __bfs_forwards(src_entry, target, match, skip, target_entry); - if (unlikely(bfs_error(ret))) + if (bfs_error(ret)) print_bfs_bug(ret); return ret; @@ -2936,7 +2936,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * in the graph whose neighbours are to be checked. */ ret = check_noncircular(next, prev, trace); - if (unlikely(bfs_error(ret) || ret == BFS_RMATCH)) + if (bfs_error(ret) || unlikely(ret == BFS_RMATCH)) return 0; if (!check_irq_usage(curr, prev, next)) -- 2.30.2