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 236C2C43381 for ; Mon, 18 Mar 2019 08:57:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DEFDF217F4 for ; Mon, 18 Mar 2019 08:57:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="WALvay8T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727184AbfCRI5z (ORCPT ); Mon, 18 Mar 2019 04:57:55 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:42831 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727132AbfCRI5x (ORCPT ); Mon, 18 Mar 2019 04:57:53 -0400 Received: by mail-pg1-f195.google.com with SMTP id b2so10894430pgl.9 for ; Mon, 18 Mar 2019 01:57:52 -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=a28sVP+44q7iWCcjuw3hwp2P++bKgYYvw2MgXjP7Hz8=; b=WALvay8TF29d6RStO9aJvOGN2gEAf/t1teJIDI5Cdg4+cW8zUg2wf2O4v1I51xezRp qEOEUNwjk76d+E4Hx4zbJtex8OYGxhq1+fC+IN5nvArrlD24ZrGaiMCTkWI1VkJNqPBW 7N7nBqxpG203906AM+NYbwsNKOh4CtXt2z7FH8nHXV51fluhr4kV8HV5D35x+/4mBj9A ECIBGf4lLQW3JrWQNbVVH7uFq2mQHYbaHYjj+9XVwbydQbfcnh7vObRf4hDnFOthY8m8 p6SG2VbWjOvoZ+AC/F2+ubyn80iAoy9GBijZULUuw/8pWc43zqDpc3CRblLB2dhXCAqG vl8w== 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=a28sVP+44q7iWCcjuw3hwp2P++bKgYYvw2MgXjP7Hz8=; b=ZBH0MaVgdwkO/ckQJ1O9YHIq15VDIPNPWDJpDVxg+teTWWN26JfJ9jmWhGduOoJLh+ y4kYnGy/uf8zq2IcucEyAGzCK3QgE56N1sP74KIZ7Rsu4u2s5JPW9Mn5l5zNox9C5/Ts Og594mzHWh44QbV0itum2q+uqTFAH1+RJdXauXTfHnD7nAcW5mdv5ca4/Pv/uV5Ngilc VRqawcpp3GjSZuhMaTLsJmhWMXdwQQgFxp4Gei66MFBaEGkEnor1u62LON2mvC1rvlOb v4vCvgt5B2DllOX5pHExlXeoT1Hyz9Au9TEZLpeAoozFi1xjYsfdXdSVm2Y+iDpcL5Ru mi7A== X-Gm-Message-State: APjAAAXfl0uAnM7c/7ntX9gp6n5g7G8v2dWnhGtUmEXTviFqxJzuCDKV fc+Bmh5lVFRq2A1hgAdxZB0= X-Google-Smtp-Source: APXvYqxP9hi4PR/pPgF+fZ9v1QeBzUnkx8fw/aa7I2yvenOw8h9kS9JD8QiVj/GwglbvIThETLpFmg== X-Received: by 2002:a65:410a:: with SMTP id w10mr16289028pgp.206.1552899471948; Mon, 18 Mar 2019 01:57:51 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id k8sm11147024pgq.37.2019.03.18.01.57.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 18 Mar 2019 01:57:51 -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, Yuyang Du Subject: [PATCH v2 03/19] locking/lockdep: Adjust lock usage bit character checks Date: Mon, 18 Mar 2019 16:57:17 +0800 Message-Id: <20190318085733.3143-4-duyuyang@gmail.com> X-Mailer: git-send-email 2.17.2 (Apple Git-113) In-Reply-To: <20190318085733.3143-1-duyuyang@gmail.com> References: <20190318085733.3143-1-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 1c5e947..d5b66cf 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