From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934067AbcIVDAv (ORCPT ); Wed, 21 Sep 2016 23:00:51 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:46546 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933395AbcIVDAt (ORCPT ); Wed, 21 Sep 2016 23:00:49 -0400 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com Date: Thu, 22 Sep 2016 11:57:43 +0900 From: Byungchul Park To: Peter Zijlstra Cc: Byungchul Park , Ingo Molnar , tglx@linutronix.de, Michel Lespinasse , boqun.feng@gmail.com, kirill@shutemov.name, "linux-kernel@vger.kernel.org" , linux-mm@kvack.org, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, npiggin@gmail.com Subject: Re: [PATCH v3 07/15] lockdep: Implement crossrelease feature Message-ID: <20160922025743.GO2279@X58A-UD3R> References: <1473759914-17003-1-git-send-email-byungchul.park@lge.com> <1473759914-17003-8-git-send-email-byungchul.park@lge.com> <20160913150554.GI2794@worktop> <20160913193829.GA5016@twins.programming.kicks-ass.net> <20160914081117.GK5008@twins.programming.kicks-ass.net> <20160919024102.GF2279@X58A-UD3R> <20160919085009.GT5016@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160919085009.GT5016@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 19, 2016 at 10:50:09AM +0200, Peter Zijlstra wrote: > Clearly I'm still missing stuff... By the way.. do I have to explain more? Lack of explanation? It would be the best to consider 'all valid acquires', which can occur deadlock, but it looks impossible without parsing all code in head. So it would be the safest to rely on 'acquires which actually happened', even though it might be 'random acquires' among all valid acquires. This conservative appoach is exactly same as how original lockdep is doing. Let me explain more if you doubt it.