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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 2E244C43218 for ; Thu, 25 Apr 2019 19:48:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35681206BF for ; Thu, 25 Apr 2019 19:48:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VK9BPAw2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728035AbfDYTsm (ORCPT ); Thu, 25 Apr 2019 15:48:42 -0400 Received: from merlin.infradead.org ([205.233.59.134]:55216 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726196AbfDYTsm (ORCPT ); Thu, 25 Apr 2019 15:48:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=gSGV6pj1xTOJsvQqk01AL/unLk9JzTaCItBvbXk2Ytg=; b=VK9BPAw2Zil3nZ4/sJgXS/pWJ emi0uLXCg/hPYvDVFdGantn9QxL9TFSjVkC8IbZKgwN06J/B9mDxKnz6dznzKUIwm/LV7qcaQcyML c9V2n995g5gpL0/Vy1iXw5jFJgUUbHwmP+48z9RF3IcPcerPssU8moR0xz5AhM0MwhnNzdgwrNx6u EdjL0ZCBoJGYLlP58oRzaDHh1KhHMVzAlf/Rj8xgl1BQYK0nNEMhOVEcjFC7GyC/UIZdO+UYDeVv/ COBai+WWOrhT1WengCeM1fZKLRxa8gWsxsIMrwSwkNijojd/RUg+jhPQszx9zivAU1oFA1xFpgU6f N2u10LzFw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJkMC-0001VJ-PL; Thu, 25 Apr 2019 19:48:33 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 85E3729C22B12; Thu, 25 Apr 2019 21:48:31 +0200 (CEST) Date: Thu, 25 Apr 2019 21:48:31 +0200 From: Peter Zijlstra To: Yuyang Du Cc: will.deacon@arm.com, mingo@kernel.org, bvanassche@acm.org, ming.lei@redhat.com, frederic@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH 20/28] locking/lockdep: Refactorize check_noncircular and check_redundant Message-ID: <20190425194831.GV12232@hirez.programming.kicks-ass.net> References: <20190424101934.51535-1-duyuyang@gmail.com> <20190424101934.51535-21-duyuyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190424101934.51535-21-duyuyang@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 24, 2019 at 06:19:26PM +0800, Yuyang Du wrote: > These two functions now handle different check results themselves. A new > check_path function is added to check whether there is a path in the > dependency graph. No functional change. This looks good, however I completely forgot we still had the redundant thing. It was added for cross-release (which has since been reverted) which would generate a lot of redundant links (IIRC) but having it makes the reports more convoluted -- basically, if we had an A-B-C relation, then A-C will not be added to the graph because it is already covered. This then means any report will include B, even though a shorter cycle might have been possible. Maybe we should make the whole redundant check depend on LOCKDEP_SMALL for now.