Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936207AbcCQXLl (ORCPT ); Thu, 17 Mar 2016 19:11:41 -0400 Received: from casper.infradead.org ([85.118.1.10]:47023 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935743AbcCQXLb (ORCPT ); Thu, 17 Mar 2016 19:11:31 -0400 Date: Fri, 18 Mar 2016 00:11:28 +0100 From: Peter Zijlstra To: "Paul E. McKenney" Cc: Chris Metcalf , Russell King , Thomas Gleixner , Aaron Tomlin , Ingo Molnar , Andrew Morton , Daniel Thompson , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/4] nmi_backtrace: add more trigger_*_cpu_backtrace() methods Message-ID: <20160317231128.GB6344@twins.programming.kicks-ass.net> References: <1458147733-29338-1-git-send-email-cmetcalf@mellanox.com> <1458147733-29338-2-git-send-email-cmetcalf@mellanox.com> <20160317193600.GY6344@twins.programming.kicks-ass.net> <20160317225557.GA4287@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160317225557.GA4287@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 360 Lines: 8 On Thu, Mar 17, 2016 at 03:55:57PM -0700, Paul E. McKenney wrote: > The RCU stall-warn stack traces can be ugly, agreed. Ugly isn't the problem, completely random bollocks that puts you on the wrong path was more the problem. It uses a stack pointer saved at some random time in the past to start unwinding an active stack from. Completely and utter misery.