From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753731AbZHBVJS (ORCPT ); Sun, 2 Aug 2009 17:09:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753646AbZHBVJR (ORCPT ); Sun, 2 Aug 2009 17:09:17 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:33503 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753624AbZHBVJQ (ORCPT ); Sun, 2 Aug 2009 17:09:16 -0400 Date: Sun, 2 Aug 2009 14:08:09 -0700 From: Andrew Morton To: Ingo Molnar Cc: paulmck@linux.vnet.ibm.com, mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, torvalds@linux-foundation.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/debug] debug lockups: Improve lockup detection Message-Id: <20090802140809.7ec4bb6b.akpm@linux-foundation.org> In-Reply-To: <20090802204150.GB3986@elte.hu> References: <20090802114545.f1520c81.akpm@linux-foundation.org> <20090802192657.GA21882@elte.hu> <20090802123958.cbd497a0.akpm@linux-foundation.org> <20090802204150.GB3986@elte.hu> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2 Aug 2009 22:41:50 +0200 Ingo Molnar wrote: > > * Andrew Morton wrote: > > > On Sun, 2 Aug 2009 21:26:57 +0200 Ingo Molnar wrote: > > > > > > I think this just broke all non-x86 non-sparc SMP architectures. > > > > > > Yeah - it 'broke' them in the sense of them not having a working > > > trigger_all_cpu_backtrace() implementation to begin with. > > > > c'mon. It broke them in the sense that sysrq-l went from "works" > > to "doesn't work". > > You are right (i broke it with my patch) but the thing is, sysrq-l > almost useless currently: it uses schedule_work() which assumes a > mostly working system with full irqs and scheduling working fine. > Now, i dont need sysrq-l on mostly working systems. > > So the 'breakage' is of something that was largely useless: and now > you put the onus of implementing it for _all_ architectures (which i > dont use) on me? I never said that. It's appropriate that those architectures be left with their existing level of functionality/usefulness, as you're already discussing. > > It's better to break the build or to emit warnings than to > > silently and secretly break their stuff. > > But that warning will bounce the ball back to me, wont it? My patch > will be blamed for 'breaking' those architectures, right? It's a very crude and somewhat rude way of communicating information to other architecture maintainers. A better way would be to send them an email explaining the problem and outlining some solutions, no?