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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 BC6EDC282CE for ; Wed, 24 Apr 2019 10:23:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DBE3218D3 for ; Wed, 24 Apr 2019 10:23:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="l7RJe13w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727625AbfDXKXM (ORCPT ); Wed, 24 Apr 2019 06:23:12 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:41585 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728953AbfDXKUh (ORCPT ); Wed, 24 Apr 2019 06:20:37 -0400 Received: by mail-pf1-f196.google.com with SMTP id 188so9076425pfd.8 for ; Wed, 24 Apr 2019 03:20:37 -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=byZGzHb7mBNvQYwj1NTd7kgCiIjW1R3pXbNxGql0JSY=; b=l7RJe13wIUPyhqAezRTph1hO06w08OQqzXcgrOTHCGZrOCgt3Nd7fngbQbOy3594Od Nwn5wqo0LPKZJ40jVWtOd7XhgnmTlxxbuUMF3E8kIxSJqcHJDb9pbB9M4J/h8bcZeUPI x90gDkU396re3dG9QYmvA8FdNSAuICtJfljAhAJQxGLRI9zFUWzVW7h9NUX8wy6KwuCX jX9woaf1v267+HRaj3JD4RzxATeU4h0emJVJBRJXqj61Qsg6RX+cXh3Blpt0dp9hprRr RsoaQKIBo4FQpb/O1k81pbI4m56xnAP97uQ65tUJfFq0QxVrQ7N9NM4mOz5wabJMg/sv x6BQ== 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=byZGzHb7mBNvQYwj1NTd7kgCiIjW1R3pXbNxGql0JSY=; b=ufwSTy8o0MmvQ/sjjP9/i+/WBWGB/7nwwswO7+2XWiKJE8iPO/q4+kykxKwPO98LkZ 6+hEI+X2LovGWK0hVrJxdPprs0LFwUxsBMXuaSRzJq3KeYYyC5miWjfkGRsLSEsOxv6P k6zJv7htEkbnNsxmptso9UnhGWGqCe5Kr+wTV48cZtPAO99W5aqDOj1Jw0TmCjQVIBJT D5xMqCKkWobCQaTG17rdSDPQTv9Fun7bx9KfSCQK8wLoCgsHZGoQSBFAEGfVboqkAb6K vKc+pmos6qNEzfhoaS9vTTkwpJYUWNYNcP/s5fBRx8N54puj+PKX1mkaQ+/l/jSySPbj 8EEQ== X-Gm-Message-State: APjAAAV76Tx5sCBwg8zOa+FQjahz3MS9LBviCwIF6JnKXWXp5VxVJCiH DcoTYxH1p6QahVk3GrUujzc= X-Google-Smtp-Source: APXvYqz2d565h29uKjEh7JBAgOy8m/5h+2Bo01y3LRLBN7+LyASaSuCZleXGuQFbJv9NIzxDCDvgBA== X-Received: by 2002:a62:1249:: with SMTP id a70mr32727130pfj.160.1556101237377; Wed, 24 Apr 2019 03:20:37 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id v19sm25051604pfn.62.2019.04.24.03.20.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Apr 2019 03:20:36 -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, Yuyang Du Subject: [PATCH 03/28] locking/lockdep: Adjust lock usage bit character checks Date: Wed, 24 Apr 2019 18:19:09 +0800 Message-Id: <20190424101934.51535-4-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190424101934.51535-1-duyuyang@gmail.com> References: <20190424101934.51535-1-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 The lock usage bit characters are defined and determined with tricks. Add some explanation to make it a bit clearer, then adjust the logic to check the usage, which optimizes the code a bit. No functional change. Signed-off-by: Yuyang Du --- kernel/locking/lockdep.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 4bf396b..ba0080a 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -499,15 +499,26 @@ static inline unsigned long lock_flag(enum lock_usage_bit bit) static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit) { + /* + * The usage character defaults to '.' (i.e., irqs disabled and not in + * irq context), which is the safest usage category. + */ char c = '.'; - if (class->usage_mask & lock_flag(bit + LOCK_USAGE_DIR_MASK)) + /* + * The order of the following usage checks matters, which will + * result in the outcome character as follows: + * + * - '+': irq is enabled and not in irq context + * - '-': in irq context and irq is disabled + * - '?': in irq context and irq is enabled + */ + if (class->usage_mask & lock_flag(bit + LOCK_USAGE_DIR_MASK)) { c = '+'; - if (class->usage_mask & lock_flag(bit)) { - c = '-'; - if (class->usage_mask & lock_flag(bit + LOCK_USAGE_DIR_MASK)) + if (class->usage_mask & lock_flag(bit)) c = '?'; - } + } else if (class->usage_mask & lock_flag(bit)) + c = '-'; return c; } -- 1.8.3.1