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=-8.9 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,URIBL_BLOCKED,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 B4E31C10F11 for ; Wed, 24 Apr 2019 10:22:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 844952175B for ; Wed, 24 Apr 2019 10:22:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="modEms7k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729962AbfDXKWv (ORCPT ); Wed, 24 Apr 2019 06:22:51 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:39631 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728141AbfDXKVF (ORCPT ); Wed, 24 Apr 2019 06:21:05 -0400 Received: by mail-pg1-f195.google.com with SMTP id l18so9032719pgj.6 for ; Wed, 24 Apr 2019 03:21:04 -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=B0zIug3byHnqFY6zU5sDm8sMZPCbIfr9tms2OJ2D7bM=; b=modEms7kAWuIj4U05MaCKH7+t44MS4tmNh9qXirSBnDawIXj80b+oBRyWdBq4FAqhY DVZtrlSdsbVTGZ/zwaBSpxdw1cLq78S/Scury6erBjmLOvNN8N+AW3/X7FccCfj1ISOk tT1kMgBvG6j9axARhFrRvIeHtM4X/AvUH6JSUIDlQqiRigh/dJck72uTU4cvVKQbUeSH J2Hy4KM8XgYB1aVqGYG7Jp4GhKVXzA09toczw4zhN5anRwaKR+uKjJo4w+z5JwxmsZc9 jMTQnyDa/bFLN3oMXMGcc9x8LSc58Nil67MuTtzyK5iKvBvEaIBIAw5d2XCBlXQE6cYU 7upQ== 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=B0zIug3byHnqFY6zU5sDm8sMZPCbIfr9tms2OJ2D7bM=; b=BwR8AxNOWu0cs1Woe/7mywVDaCsU+FGJm2lFlJhdaeFeo/qbVMcFBzTZFYFnrVhC6d aFiLmWQfnJog/X4ToXgcAkOY+DgF/Z00Yi452w6jBg13z/IKctWJafuW+lhouAgEOnyu qVLzydRKFwPLeYB2TG5IwbeComfILOrHT9Yij4F6kgTNdgqkIyYisXdWIxkRU4VesyEj pKXkXAPxSVXCFzSBKLGCoyMZANOUB+xzPRfZY6pvfi8m7/9mGFSarkrR1/RKeOnoVg/a oS2Za9b3LXEGyWiBmukAvqi9v5VKmB9rvWRVOpXo26WhYuVtbvoSn2jYdfSh4YGg+5/D 5XeA== X-Gm-Message-State: APjAAAWOZzACbFgU24AAes8EAWqFrea4qGOvPpvJVbyQjCum7Z8zUE0r a8W1p/xLUoyOWxfoq/Z/9GA= X-Google-Smtp-Source: APXvYqwp/8i/93ZcWbvz97SgnSDfEddtsPMSbrzjjyrxYwl9wVDLkdUVa44/84qlNUVhiFe2oRztrw== X-Received: by 2002:a62:6c43:: with SMTP id h64mr32818844pfc.123.1556101264605; Wed, 24 Apr 2019 03:21:04 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id v19sm25051604pfn.62.2019.04.24.03.21.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Apr 2019 03:21:04 -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 12/28] locking/lockdep: Change type of the element field in circular_queue Date: Wed, 24 Apr 2019 18:19:18 +0800 Message-Id: <20190424101934.51535-13-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190424101934.51535-1-duyuyang@gmail.com> References: <20190424101934.51535-1-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 element field is an array in struct circular_queue to keep track of locks in the search. Making it the same type as the locks avoids type cast. Also fix a typo and elaborate the comment above struct circular_queue. No functional change. Signed-off-by: Yuyang Du Reviewed-by: Bart Van Assche --- kernel/locking/lockdep.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 0543872..683aaf60 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1257,13 +1257,16 @@ static int add_lock_to_list(struct lock_class *this, #define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1) /* - * The circular_queue and helpers is used to implement the - * breadth-first search(BFS)algorithem, by which we can build - * the shortest path from the next lock to be acquired to the - * previous held lock if there is a circular between them. + * The circular_queue and helpers are used to implement the graph + * breadth-first search (BFS) algorithm, by which we can determine whether + * there is a path from the next lock to be acquired to a previous held + * lock, which indicates that adding the -> lock dependency + * produces a circle in the lock dependency graph. Breadth-first search + * instead of depth-first search is used for finding the shortest circular + * path. */ struct circular_queue { - unsigned long element[MAX_CIRCULAR_QUEUE_SIZE]; + struct lock_list *element[MAX_CIRCULAR_QUEUE_SIZE]; unsigned int front, rear; }; @@ -1289,7 +1292,7 @@ static inline int __cq_full(struct circular_queue *cq) return ((cq->rear + 1) & CQ_MASK) == cq->front; } -static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) +static inline int __cq_enqueue(struct circular_queue *cq, struct lock_list *elem) { if (__cq_full(cq)) return -1; @@ -1299,7 +1302,7 @@ static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) return 0; } -static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem) +static inline int __cq_dequeue(struct circular_queue *cq, struct lock_list **elem) { if (__cq_empty(cq)) return -1; @@ -1377,12 +1380,12 @@ static int __bfs(struct lock_list *source_entry, goto exit; __cq_init(cq); - __cq_enqueue(cq, (unsigned long)source_entry); + __cq_enqueue(cq, source_entry); while (!__cq_empty(cq)) { struct lock_list *lock; - __cq_dequeue(cq, (unsigned long *)&lock); + __cq_dequeue(cq, &lock); if (!lock->class) { ret = -2; @@ -1406,7 +1409,7 @@ static int __bfs(struct lock_list *source_entry, goto exit; } - if (__cq_enqueue(cq, (unsigned long)entry)) { + if (__cq_enqueue(cq, entry)) { ret = -1; goto exit; } -- 1.8.3.1