Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753975AbdLNR7h (ORCPT ); Thu, 14 Dec 2017 12:59:37 -0500 Received: from merlin.infradead.org ([205.233.59.134]:33848 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753668AbdLNR7g (ORCPT ); Thu, 14 Dec 2017 12:59:36 -0500 Date: Thu, 14 Dec 2017 18:59:31 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: LKML , Ingo Molnar , Thomas Gleixner , Andrew Morton Subject: Re: [PATCH] lockdep: Show up to three levels for a deadlock scenario Message-ID: <20171214175931.mlvr7lk7bcnsqu5i@hirez.programming.kicks-ass.net> References: <20171214123852.515257aa@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171214123852.515257aa@gandalf.local.home> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 555 Lines: 10 On Thu, Dec 14, 2017 at 12:38:52PM -0500, Steven Rostedt wrote: > > Currently, when lockdep detects a possible deadlock scenario that involves 3 > or more levels, it just shows the chain, and a CPU sequence order of the > first and last part of the scenario, leaving out the middle level and this > can take a bit of effort to understand. By adding a third level, it becomes > easier to see where the deadlock is. So is anybody actually using this? This (together with the callchain for #0) is always the first thing of the lockdep output I throw away.