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 80222C48BE6 for ; Wed, 16 Jun 2021 14:42:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 692B1610A1 for ; Wed, 16 Jun 2021 14:42:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234138AbhFPOon (ORCPT ); Wed, 16 Jun 2021 10:44:43 -0400 Received: from pv50p00im-zteg10011401.me.com ([17.58.6.41]:60303 "EHLO pv50p00im-zteg10011401.me.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233919AbhFPOom (ORCPT ); Wed, 16 Jun 2021 10:44:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=me.com; s=1a1hai; t=1623854556; bh=u1X+vt8zI6f6plB9FC1PC3QZFqTsSMdz/tE/Bb75RRk=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=WrnIglfVudnLX73s4JDh7q6WjGXSJIDxhbuti2wnu5rdHFG8SIR3UQphbepgf3Nl1 xQRc2rp4D75MKaYQxWfSytlv7dbke7lrgM6naIbnYkx56BzvOR48uCEjYFEtc5Nrmp d7xVaX0CDt/ufBRfA+fv7m2c/yULpuTRLaIz0tmLl5SNKkT65kvd2IhbIdN+jgiAWC nW4DRTcygqDunahkL/MQ9ZEWT9YOmrHoDBUGCxaUo50Xp/sCI0eMXVbtRmFbY3eznx 8JJssPY4Xt31Pb2EHfLzgN69lN6jTEka7iwH84awE5cZY0d4nEDNEZ9OEyBUF+jRUH cg48FuTebDRCw== Received: from xiongwei.. (unknown [120.245.2.120]) by pv50p00im-zteg10011401.me.com (Postfix) with ESMTPSA id 58A839005F1; Wed, 16 Jun 2021 14:42:27 +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] locking/lockdep: unlikely bfs error check Date: Wed, 16 Jun 2021 22:42:09 +0800 Message-Id: <20210616144210.278662-1-sxwjean@me.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-06-16_07:2021-06-15,2021-06-16 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-2106160085 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiongwei Song The error from graph walk is small probability event, so unlikely bfs_error can improve performance a little bit. Signed-off-by: Xiongwei Song --- kernel/locking/lockdep.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 074fd6418c20..af8c9203cd3e 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2646,7 +2646,7 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, bfs_init_rootb(&this, prev); ret = __bfs_backwards(&this, &usage_mask, usage_accumulate, usage_skip, NULL); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -2664,7 +2664,7 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, bfs_init_root(&that, next); ret = find_usage_forwards(&that, forward_mask, &target_entry1); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -2679,7 +2679,7 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, backward_mask = original_mask(target_entry1->class->usage_mask); ret = find_usage_backwards(&this, backward_mask, &target_entry); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -2998,7 +2998,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * Is the -> link redundant? */ ret = check_redundant(prev, next); - if (bfs_error(ret)) + if (unlikely(bfs_error(ret))) return 0; else if (ret == BFS_RMATCH) return 2; @@ -3911,7 +3911,7 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this, bfs_init_root(&root, this); ret = find_usage_forwards(&root, usage_mask, &target_entry); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -3946,7 +3946,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this, bfs_init_rootb(&root, this); ret = find_usage_backwards(&root, usage_mask, &target_entry); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } -- 2.30.2