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=-8.1 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_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 C935AC43381 for ; Tue, 26 Feb 2019 10:03:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 974CD2173C for ; Tue, 26 Feb 2019 10:03:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XNerrDyo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728040AbfBZKDr (ORCPT ); Tue, 26 Feb 2019 05:03:47 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:43457 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727813AbfBZKDo (ORCPT ); Tue, 26 Feb 2019 05:03:44 -0500 Received: by mail-pl1-f194.google.com with SMTP id m10so5987216plt.10 for ; Tue, 26 Feb 2019 02:03:44 -0800 (PST) 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; bh=iKgSR3pgBbxBFbm4Ql4W6QsvFtlkjW+qw2rlTVlUse8=; b=XNerrDyomy7JLG77HEmJHx9s0r0RH/KfGNiMdgDGtkHfd5/6/F46oEVdSK1Stlpk0F IhkXp6d/2g47nyAxMDyw2kqLUCZFjbPUYaXgU0aglwHnDAGoGsY/zLVToZxkK0z+25zg g9MbZLN6z66bbPWty+afg1eiEM8l14mnX+haIomj2SYD9OyoScDZK/6frlpMOPeh/bLQ GTspI4byHD7ZyVULgyckoxs/qBE8ItyV4Mjl7VT9tYE3F1dkhS+YRjcy0+8foV0UntqT kiVnlKshIdd1LCPHGI9tcN6Bu4CJcclyyTqKwBcedLEVuRAXf8D11hzjT98kaAVYaq0/ c20Q== 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; bh=iKgSR3pgBbxBFbm4Ql4W6QsvFtlkjW+qw2rlTVlUse8=; b=RKJj2NQG3SPd6iq6twrqww4NCo0GPrNN9jgvLb1DftQ6IfHQ6k5yiHBjRsiLfbEEUE /xDMo7xC9UzlzIK7WrprYP82R3xYADSDGc1TC/9Kap5cTqIbNXDeCvI1OFK8w3pAK3MS MOiU7OMsTBCyNzoNPr+aYaJLdZAt8T2kVefRxKtzIdy/RTdW2bUKfFIdatxtERUE1QMz HYDiK/NZlTadTjWwJYg+k5PcbaLNiOpp++xZaT83cU5k326HcjTclt4WZK/LnoybUwP8 ETZs7dU8IPRiIRIzQ0zrDAF7XNlO5i68U7PY8z8k35q2ZWcnM1lR6g1dK6UpsNcl4OEA SvYA== X-Gm-Message-State: AHQUAuYcvGKwoO65jqDE5WkoiyNdiK7CwPrKF33lmGN2juEtCzrP7rVl dg9B965UTOzIgIxN+TCXsZc7qefu1Ts= X-Google-Smtp-Source: AHgI3IbaNU4IafCO2jzkU9NCkW04HANbifT9Uv0oomw26ES93Sl0TKJQaE/T+fgh1n5Xn5PD8oimZQ== X-Received: by 2002:a17:902:7782:: with SMTP id o2mr25616885pll.315.1551175423846; Tue, 26 Feb 2019 02:03:43 -0800 (PST) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id y6sm12045520pfy.87.2019.02.26.02.03.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Feb 2019 02:03:43 -0800 (PST) From: Yuyang Du To: peterz@infradead.org, mingo@kernel.org Cc: linux-kernel@vger.kernel.org, Yuyang Du Subject: [PATCH 3/8] locking/lockdep: Adjust lock usage bit character checks Date: Tue, 26 Feb 2019 18:03:22 +0800 Message-Id: <20190226100327.19340-4-duyuyang@gmail.com> X-Mailer: git-send-email 2.17.2 (Apple Git-113) In-Reply-To: <20190226100327.19340-1-duyuyang@gmail.com> References: <20190226100327.19340-1-duyuyang@gmail.com> 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. Use a macro and add some explanation to make it a bit more clear. 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 ++++++++++++++++----- kernel/locking/lockdep_internals.h | 1 + 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 41eab3d..8b8495e 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -471,15 +471,26 @@ 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 + 2)) + /* + * 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_TO_ENABLED_STEP)) { c = '+'; - if (class->usage_mask & lock_flag(bit)) { - c = '-'; - if (class->usage_mask & lock_flag(bit + 2)) + if (class->usage_mask & lock_flag(bit)) c = '?'; - } + } else if (class->usage_mask & lock_flag(bit)) + c = '-'; return c; } diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 2ebb9d0..2815e85 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -25,6 +25,7 @@ enum lock_usage_bit { #define LOCK_USAGE_READ_MASK 1 #define LOCK_USAGE_DIR_MASK 2 #define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK)) +#define LOCK_USAGE_TO_ENABLED_STEP 2 /* * Usage-state bitmasks: -- 1.8.3.1