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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 37D93C4321A for ; Fri, 28 Jun 2019 09:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BC1F208E3 for ; Fri, 28 Jun 2019 09:15:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fVcaiuJe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726675AbfF1JPs (ORCPT ); Fri, 28 Jun 2019 05:15:48 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:35356 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726508AbfF1JPs (ORCPT ); Fri, 28 Jun 2019 05:15:48 -0400 Received: by mail-pl1-f196.google.com with SMTP id w24so2911785plp.2 for ; Fri, 28 Jun 2019 02:15:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=MLF10tHXSYj9nlQOchCpax5oxJ4CM95wZZZyCb5aYKQ=; b=fVcaiuJep4MSYMlT4ryvMOy4WMX248CdSsJXwtQNkTSEFa+jimM0sjIK5pCODQ0wrG SDLLzBFHmhxERswiwzL9RaK5w8vKu3/oPUd+v5nBmWxGdR1amcJg5H9PFxcVXpgNpTxE UqZxB/Gb5RdsFSqiXfRq+gzzJMmq2mHZksoyuDDkAwrdwhR9S9X/sp5kwErjq9NX3DBo WFqkbrJlJbx8DFwT8Kp63wPycofD8cD/pR4j+VEBJx7p9JrSfPZ/kM5ERq+yEMbYtBgv +X5J30h0y6ni9/aULs7bSjKFken08KuoqOPmUWsFxKp1KUslyEnMbYeJJPQOSh54lAk8 OWaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=MLF10tHXSYj9nlQOchCpax5oxJ4CM95wZZZyCb5aYKQ=; b=ppvjvp3fXAkqAsgUZakTgzz1YUfwDUsAuWxDYlr9Y/eiucEebHbxBJIB88tUBQ4LkE FntjYXJPNSQcu79rkVnelX+RHPw1mnq/lo0gwm8GrYpmptsQRGBQGt86qFPiUOvOK1Kh 4GkR+pak5LOlvGlWoXlk6S3IVNn4Px9DMoC+4j8oZgDoAuOhwjyn+aEushVtHH8e7jou 7yR+4HXa1ArlJzX14eiQOjbbB0hjJwTzWM1hYfOqJocNsILRQrJ3lPrAfxJvgli4MNua JWT7E1mq/ZnEQ0w6H/VOQC06Fv8XF5BK6DMnj9Go9+H/CKm8QgKFnLfHAPF8Yfy5Kkvb H6Tg== X-Gm-Message-State: APjAAAWlH2WqBl7vkz0EEM2jd/O7yyr0tCHnl6UCqhOgtS9vDlml+5Vq IOkvTwD1NRxzyDSmRPgEWHg= X-Google-Smtp-Source: APXvYqwQ9/oC6Q5HdxnbnLCzvvjjjNyj2w6SeKAEzz4kBImalTAq5TojsXsdjvms4wvmjJqErm70pA== X-Received: by 2002:a17:902:363:: with SMTP id 90mr10061456pld.340.1561713347883; Fri, 28 Jun 2019 02:15:47 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id x65sm1754521pfd.139.2019.06.28.02.15.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Jun 2019 02:15:47 -0700 (PDT) From: Yuyang Du To: peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org Cc: bvanassche@acm.org, ming.lei@redhat.com, frederic@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, longman@redhat.com, paulmck@linux.vnet.ibm.com, boqun.feng@gmail.com, Yuyang Du Subject: [PATCH v3 01/30] locking/lockdep: Rename deadlock check functions Date: Fri, 28 Jun 2019 17:14:59 +0800 Message-Id: <20190628091528.17059-2-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190628091528.17059-1-duyuyang@gmail.com> References: <20190628091528.17059-1-duyuyang@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Deadlock checks are performed at two places: - Within current's held lock stack, check for lock recursion deadlock. - Within dependency graph, check for lock inversion deadlock. Rename the two relevant functions for later use. Plus, with recursive-read locks, only a dependency circle in graph is not a sufficient condition for lock inversion deadlocks anymore, so check_noncircular() is not entirely accurate. No functional change. Signed-off-by: Yuyang Du --- kernel/locking/lockdep.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 341f521..e30e9e4 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1714,8 +1714,8 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class) * Print an error and return 0 if it does. */ static noinline int -check_noncircular(struct held_lock *src, struct held_lock *target, - struct lock_trace *trace) +check_deadlock_graph(struct held_lock *src, struct held_lock *target, + struct lock_trace *trace) { int ret; struct lock_list *uninitialized_var(target_entry); @@ -2302,7 +2302,8 @@ static inline void inc_chains(void) } /* - * Check whether we are holding such a class already. + * Check whether we are holding such a class already in the current + * held lock stack. * * (Note that this has to be done separately, because the graph cannot * detect such classes of deadlocks.) @@ -2310,7 +2311,7 @@ static inline void inc_chains(void) * Returns: 0 on deadlock detected, 1 on OK, 2 on recursive read */ static int -check_deadlock(struct task_struct *curr, struct held_lock *next) +check_deadlock_current(struct task_struct *curr, struct held_lock *next) { struct held_lock *prev; struct held_lock *nest = NULL; @@ -2394,7 +2395,7 @@ static inline void inc_chains(void) /* * Prove that the new -> dependency would not - * create a circular dependency in the graph. (We do this by + * create a deadlock scenario in the graph. (We do this by * a breadth-first search into the graph starting at , * and check whether we can reach .) * @@ -2402,7 +2403,7 @@ static inline void inc_chains(void) * MAX_CIRCULAR_QUEUE_SIZE) which keeps track of a breadth of nodes * in the graph whose neighbours are to be checked. */ - ret = check_noncircular(next, prev, trace); + ret = check_deadlock_graph(next, prev, trace); if (unlikely(ret <= 0)) return 0; @@ -2878,7 +2879,7 @@ static int validate_chain(struct task_struct *curr, * The simple case: does the current hold the same lock * already? */ - int ret = check_deadlock(curr, hlock); + int ret = check_deadlock_current(curr, hlock); if (!ret) return 0; -- 1.8.3.1