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=-9.0 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 20641C3A59F for ; Thu, 29 Aug 2019 08:31:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E705D233FF for ; Thu, 29 Aug 2019 08:31:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AP9qaacm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727001AbfH2Ibu (ORCPT ); Thu, 29 Aug 2019 04:31:50 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:43598 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726637AbfH2Ibt (ORCPT ); Thu, 29 Aug 2019 04:31:49 -0400 Received: by mail-pl1-f193.google.com with SMTP id 4so1230351pld.10 for ; Thu, 29 Aug 2019 01:31:49 -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=PdlvwnGEzcFCAXeOFNM8mKM5jXwMmc9nBvJCjWEqLJs=; b=AP9qaacmgc66TcZAS96mcNHpmHkXa2YSjhhR+Zm0HxyoCaYgyltFEztJRiFJzy7qsT sfa8sVQIXUrFxLLbcEnMR4b93etILParDz+y/cCdUoyHPdii4l9u3866Kx4P82Hna8CY nuJaRUiQe9/4krZc61/4tWDfzrBMTawBTATCjRos6aUQcE1YSolst0W6t9CcXJ7PA1i/ k3NsDfQuFj8bF3aVA1dYpWezniD+Eh2jkRcId31ub8FNA3p5mbouz1etlp4hjRnQH8LQ /mk750SOBjo4JCwhcXOGGzWPHV4vlnIr1UNpnlMkrHuUuKhAlPHFIp3bPNWTebHGt3lz qpfA== 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=PdlvwnGEzcFCAXeOFNM8mKM5jXwMmc9nBvJCjWEqLJs=; b=DbGdOKrwjzl+5/s7IsiGThGGjqe3Mms2MJVOwYFF50h2QEO+rs+O6z4CFAQkgczOe/ 73TFhiux7A6ws0pJwbvWD7gQyrfNbktcdTzpdsllxn+KOCdMqUX18RamhYkytPxEpDSD zDNSvAAY19v8ta6UefqGV/ZbZ8FPWYD0zeeJfzcbiThD3/H/RVZ1mkIBo7H5POnMbgZL DQgJ62rcnm5mAUsBcNFwJtgVg/JCexC/Jbm39U46hvamwduiVPqk4EiqTvQWRJ+IIF5s vcc6k0m8jeMdzELXPooDsh6dquDU7PuvUxkNTx7YbpQlbhdM1c+bDrYVWgf0kAlYjGGz 7hgA== X-Gm-Message-State: APjAAAVmkQEF44XpnDFo9JwiiDMovU9yHBYQaq4b8yZhJTXAo82PTOuf XM99G5y9zUC3dpmt6wUOJoo= X-Google-Smtp-Source: APXvYqwJXWw1dLt0CdGMHdc4u3w30M4S6oJxAQji0hycyS5TLYhK0edFq7Fl7vHA2sbhW2EAWuvYxQ== X-Received: by 2002:a17:902:aa09:: with SMTP id be9mr8367781plb.52.1567067509064; Thu, 29 Aug 2019 01:31:49 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id v22sm1260155pgk.69.2019.08.29.01.31.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Aug 2019 01:31:48 -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 v4 01/30] locking/lockdep: Rename deadlock check functions Date: Thu, 29 Aug 2019 16:31:03 +0800 Message-Id: <20190829083132.22394-2-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190829083132.22394-1-duyuyang@gmail.com> References: <20190829083132.22394-1-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 In lockdep, deadlock checkings are carried out at two places: - In current task's held lock stack, check lock recursion deadlock scenarios. - In dependency graph, check lock inversion deadlock scenarios. Rename these two relevant functions for later use. Plus, with recursive-read locks, only a dependency circle in lock graph is not 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 3c3902c..3c89a50 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1782,8 +1782,8 @@ 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 **const trace) +check_deadlock_graph(struct held_lock *src, struct held_lock *target, + struct lock_trace **const trace) { int ret; struct lock_list *uninitialized_var(target_entry); @@ -2372,7 +2372,8 @@ 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.) @@ -2380,7 +2381,7 @@ 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; @@ -2465,7 +2466,7 @@ 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 .) * @@ -2473,7 +2474,7 @@ 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; @@ -2952,7 +2953,7 @@ 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