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 64DF9C43381 for ; Thu, 21 Mar 2019 07:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 359A32146E for ; Thu, 21 Mar 2019 07:57:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oYmI4zfb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727955AbfCUH5p (ORCPT ); Thu, 21 Mar 2019 03:57:45 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:45652 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725985AbfCUH5n (ORCPT ); Thu, 21 Mar 2019 03:57:43 -0400 Received: by mail-pf1-f193.google.com with SMTP id v21so3760927pfm.12 for ; Thu, 21 Mar 2019 00:57:42 -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; bh=ICV2JCxGUwQgyY5us2Dfx+UwHNzy7pzqiOTFmEju5+U=; b=oYmI4zfb1cxnU261zWYaMpQF8GXOawcb4RSwTUQtL5CZzd+VrWsbNBewI3j8YUkuB3 UgCvuAkyqWCjXD2FEa7QJpbjeeEVm0JvymTBe2SNcTGpMrLvR/p/Odl9jnPRKgpC+1AA wCdzz/UBSb6fKbsE/MIBOEYsIVYAMN1Uf4qYjeG+Q/rS/IuIfARIKP4/Zwh/JHL0KNd5 /7wewuFOPk6YI7pYGVFDiNYtr9Zfv7LpAVhiZys3WPVM1UC9yDOKNMXXYbUOgQy46+/o YhyHGRALpI0cDuAS+wdMglbpjjkT+P/gY40WYRbCh4OpvfZYm9WyUSx2POWE8V+b+QBz x9DQ== 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=ICV2JCxGUwQgyY5us2Dfx+UwHNzy7pzqiOTFmEju5+U=; b=b+tTkyuIw6dqvayyE3nCaoTu9zTh/1p7KfBuYfTffqQlPAXmk+OgBNdQ9Zhkd0K/ID a3P7RPF5U82YXEajQOPgvpsvKxBcc/3dKUViN3w81dEB2yWsGdp3+tMHnfGzANUVL1IE 36e3Mc4lsoU5LtqodA2QiHiAyOrzrHXIPY7r76RwD/cZntnVeJuENWJxzKhGsru0xOFE /ihu41HuqcQ/hGIBTF7KaTMNF1wC/V0DwxmXxVEUuFnYkPr+2Y2cZzMUyxRG9VQc37YK +l2BaZBiIx+T+3gslc/QyVEMfEaLxXOSABIFkoI7dzeFO3sHwsWMMZWA3J2PL8EsvKXO KL1g== X-Gm-Message-State: APjAAAWAU1+dUFBwAYnzpZPwophpX6k1O2KJMFu2xP0zpkB6GTJ0PACg Cll22b5XS3meeHkFfjFIP18= X-Google-Smtp-Source: APXvYqyGp7/bsb5rhMH45JuranEKat/rAWpQDq2PRXRvGSgw6+UiT+sPlX/Z071E1/PL6NNR87Xmuw== X-Received: by 2002:a17:902:758f:: with SMTP id j15mr2179990pll.211.1553155062430; Thu, 21 Mar 2019 00:57:42 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id e184sm6467148pfc.143.2019.03.21.00.57.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Mar 2019 00:57:41 -0700 (PDT) From: Yuyang Du To: peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org Cc: bvanassche@acm.org, ming.lei@redhat.com, linux-kernel@vger.kernel.org, joe@perches.com, Yuyang Du Subject: [PATCH v3 03/18] locking/lockdep: Adjust lock usage bit character checks Date: Thu, 21 Mar 2019 15:57:10 +0800 Message-Id: <20190321075725.14054-4-duyuyang@gmail.com> X-Mailer: git-send-email 2.17.2 (Apple Git-113) In-Reply-To: <20190321075725.14054-1-duyuyang@gmail.com> References: <20190321075725.14054-1-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 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 ++++++++++++++++----- 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 41137ad..db0473d 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -514,15 +514,26 @@ 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 d4c1974..2fd31d5 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