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 65DC2C04AAA for ; Mon, 6 May 2019 08:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37EF32087F for ; Mon, 6 May 2019 08:21:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="iHbi3M+S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726595AbfEFIUe (ORCPT ); Mon, 6 May 2019 04:20:34 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:36930 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726536AbfEFIUb (ORCPT ); Mon, 6 May 2019 04:20:31 -0400 Received: by mail-pf1-f194.google.com with SMTP id g3so6351989pfi.4 for ; Mon, 06 May 2019 01:20:31 -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=GkLxZzZEQh49peXTRh6HCXNZed/gc67U4FdgzKOiRaM=; b=iHbi3M+SN+CQ3EknQi4HBfan0m8/ckTiOHCCrTFgLS8Lk1v4r9DdCKabDsVxyLfmzP gjaOlg3DEmIvRHrI6riDUQhGdx0DJ6sgOG6He7nY6Mbw8qG51XPuOI8G6ERdJBej/nbO ibyHDhyY/ufghTKNT7wM8jPeTxhnhkQPveZKXc5+as4HO+z8ixIQUsN1DDRMWiLs0JHr 450cWoqu9jSh7YUqViRu1ZGw7Rc4R2TXyTwUu/uqKvrH5pyWtCx00wcvkzphXzFT5iCY KKk+mFjS2TvFgI8oEPWV97yz2N/ur1wRNcVMEdbqZ2Se9xifbfP3v8hNz6zX8RCsS0mk bc9Q== 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=GkLxZzZEQh49peXTRh6HCXNZed/gc67U4FdgzKOiRaM=; b=p0lbP+/5JmU4gM+iopkb7z+41PC1mvQRw9476/NBZwkpUEEcfc2mL7ny+NWKia1BBN 3snzSSmlX3mV5LIoD4HB1BLHmeatVxaKmzBnFuaC9rb9GQHRwDUzb/igOSwI2BT3rPZ9 B+4QV4U6pLBTir5/ObIdJe8nmv2/8lp5wkIWtPiZM5t5VWBYqSl26tl1JBcVohYSH447 KgZQGxu2/25B1zH3jY3pWFAyfU3MhCkiwafZ/SHnDj1WH2/g3DJurKi3uoNy5IeW45hc OmdF/6G+XEkXd6IWKhE8YnBTtAkoYaacXXui59bGqf6cxHcMlf+3Cqa9fo1QrNTIkGJ+ Dg1Q== X-Gm-Message-State: APjAAAUt8smc+tPZmSZgn6yA/6KyQ1Y0svPeQJqSd/3An5sObeSKj9jH C5jY0z32ir8T2cptKM8Ya9o= X-Google-Smtp-Source: APXvYqz6+B3v8x1Q54Bsrb3b9Ac7paHi+csFarKA7l4GCoZqNneTp8eik7Ky87ZkchBcAu/CidHTUQ== X-Received: by 2002:a62:f247:: with SMTP id y7mr31398096pfl.18.1557130830765; Mon, 06 May 2019 01:20:30 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id v19sm20958013pfa.138.2019.05.06.01.20.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 May 2019 01:20:30 -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 13/23] locking/lockdep: Change the return type of __cq_dequeue() Date: Mon, 6 May 2019 16:19:29 +0800 Message-Id: <20190506081939.74287-14-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 With the change, we can slightly adjust the code to iterate the queue in BFS search, which simplifies the code. No functional change. Signed-off-by: Yuyang Du --- kernel/locking/lockdep.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index eb8b190..5a0c908f 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1303,14 +1303,21 @@ static inline int __cq_enqueue(struct circular_queue *cq, struct lock_list *elem return 0; } -static inline int __cq_dequeue(struct circular_queue *cq, struct lock_list **elem) +/* + * Dequeue an element from the circular_queue, return a lock_list if + * the queue is not empty, or NULL if otherwise. + */ +static inline struct lock_list * __cq_dequeue(struct circular_queue *cq) { + struct lock_list * lock; + if (__cq_empty(cq)) - return -1; + return NULL; - *elem = cq->element[cq->front]; + lock = cq->element[cq->front]; cq->front = (cq->front + 1) & CQ_MASK; - return 0; + + return lock; } static inline unsigned int __cq_get_elem_count(struct circular_queue *cq) @@ -1362,6 +1369,7 @@ static int __bfs(struct lock_list *source_entry, int forward) { struct lock_list *entry; + struct lock_list *lock; struct list_head *head; struct circular_queue *cq = &lock_cq; int ret = 1; @@ -1383,10 +1391,7 @@ static int __bfs(struct lock_list *source_entry, __cq_init(cq); __cq_enqueue(cq, source_entry); - while (!__cq_empty(cq)) { - struct lock_list *lock; - - __cq_dequeue(cq, &lock); + while ((lock = __cq_dequeue(cq))) { if (!lock->class) { ret = -2; -- 1.8.3.1