Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935616AbcCQXJc (ORCPT ); Thu, 17 Mar 2016 19:09:32 -0400 Received: from casper.infradead.org ([85.118.1.10]:46989 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755403AbcCQXJb (ORCPT ); Thu, 17 Mar 2016 19:09:31 -0400 Date: Fri, 18 Mar 2016 00:09:28 +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: <20160317230928.GA6344@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: 483 Lines: 11 On Thu, Mar 17, 2016 at 03:55:57PM -0700, Paul E. McKenney wrote: > That said, RCU used to use NMI-based stack traces, but switched to the > current scheme due to the NMIs having the unfortunate habit of locking > things up, which IIRC often meant no stack traces at all. If I recall > correctly, one of the problems was self-deadlock in printk(). > > Have these problems been fixed? Improved is I think the word. Although I've butchered my printk() into absolute submission :-)