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=-8.8 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 1AF29C04AAA for ; Mon, 6 May 2019 08:22:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCC8020830 for ; Mon, 6 May 2019 08:22:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="e1i0+EuD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726415AbfEFIUD (ORCPT ); Mon, 6 May 2019 04:20:03 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:45161 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725837AbfEFIT7 (ORCPT ); Mon, 6 May 2019 04:19:59 -0400 Received: by mail-pg1-f194.google.com with SMTP id i21so6078128pgi.12 for ; Mon, 06 May 2019 01:19:59 -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=cMVBTmSR+asjmdXMW52Lr83ftcHwe5LGfvqtjWqKkaM=; b=e1i0+EuDJCKj6QbrLdXwMAtjfORD7l/YyGUVw0+RbG9okkNhDe3a1L7Z8wQ9KrhmlN Wi6Z/SBSqNjyt2FxalWBywtLKJ22ldcp8D9K5u9N4O42q1kP9RusTGOATAUpcJtD7HTQ +hlVr06uzEqhyZ2qT/q8d+F1VtxXMwyLF6yynpFZ/58bfmbRG2/Ch2agsZ4Hr4cTHsh5 kIkU3368im43o2iPHOnxgy346QzLutxY/i1d9T46OpHkG3z2CIoooAQRzcFPNTERth74 6RZrKBRqrkK6DQxFoHej1gzSddc0NpkZbrV9Q51mOHdbrOfGo+6PW+0EpNkFYYcbbbvd 7tjQ== 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=cMVBTmSR+asjmdXMW52Lr83ftcHwe5LGfvqtjWqKkaM=; b=VilEhZbU2CjrzACyNwEOqEOUySESrUYuwQqF5Pnk5xSexA284aMmk1LfUMve3zK2rC 0vqD9Cv0LZV/wruekxYpte89K8u43E95JDFRJCJhK3duMoeTTBNvrgIdMj0SMe6edRye ATGH1w1CgjYffjIUAeUX/Z0jgTr+fldk6T/tYT/iDEhPgwJ16ODZWCwsR0OYWFRKwPTK zkXPY10UlNV61Z8/64WS9hnx3EWk51rAvQ612E0p50kOUtyLhDgQcp05DI0OUWnIIpLP a0MNaOJfSmeOBEqm6p48jKGTrwiwBeHEkLX24mLb7ajXC9OHZ21c/7ziCu3+qdc+wCFk pmbA== X-Gm-Message-State: APjAAAUNsEi1KdVURTZrol7+ieEGdkGgK4bAPKUbadgkGWp7u64Vg5ya UKe94+tXn5bxGp4vxzPitH0= X-Google-Smtp-Source: APXvYqxhEfFEF4P0Gr+0Nsv7Y017Gy+tTC88EF48EWWw3v9uuaev/kf9O86n3Np1rXXbNvIdeqP0VA== X-Received: by 2002:a63:dc50:: with SMTP id f16mr30550408pgj.396.1557130798969; Mon, 06 May 2019 01:19:58 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id v19sm20958013pfa.138.2019.05.06.01.19.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 May 2019 01:19:58 -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 v2 03/23] locking/lockdep: Adjust lock usage bit character checks Date: Mon, 6 May 2019 16:19:19 +0800 Message-Id: <20190506081939.74287-4-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190506081939.74287-1-duyuyang@gmail.com> References: <20190506081939.74287-1-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 a019330..720d195 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