From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964889AbbJ0Pno (ORCPT ); Tue, 27 Oct 2015 11:43:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48700 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932256AbbJ0Pnm (ORCPT ); Tue, 27 Oct 2015 11:43:42 -0400 Date: Tue, 27 Oct 2015 11:43:42 -0400 From: Aristeu Rozanski To: Michal Hocko Cc: linux-kernel@vger.kernel.org, Greg Thelen , Johannes Weiner , linux-mm@kvack.org, cgroups@vger.kernel.org Subject: Re: [PATCH] oom_kill: add option to disable dump_stack() Message-ID: <20151027154341.GA14722@redhat.com> References: <1445634150-27992-1-git-send-email-arozansk@redhat.com> <20151026172012.GC9779@dhcp22.suse.cz> <20151026174048.GP15046@redhat.com> <20151027080920.GA9891@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151027080920.GA9891@dhcp22.suse.cz> 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 Hi Michal, On Tue, Oct 27, 2015 at 09:09:21AM +0100, Michal Hocko wrote: > On Mon 26-10-15 13:40:49, Aristeu Rozanski wrote: > > Hi Michal, > > On Mon, Oct 26, 2015 at 06:20:12PM +0100, Michal Hocko wrote: > [...] > > > Would it make more sense to distinguish different parts of the OOM > > > report by loglevel properly? > > > pr_err - killed task report > > > pr_warning - oom invocation + memory info > > > pr_notice - task list > > > pr_info - stack trace > > > > That'd work, yes, but I'd think the stack trace would be pr_debug. At a > > point that you suspect the OOM killer isn't doing the right thing picking > > up tasks and you need more information. > > Stack trace should be independent on the oom victim selection because > the selection should be as much deterministic as possible - so it should > only depend on the memory consumption. I do agree that the exact trace > is not very useful for the (maybe) majority of OOM reports. I am trying > to remember when it was really useful the last time and have trouble to > find an example. So I would tend to agree that pr_debug would me more > suitable. Only problem I see so far with this approach is that it'll require reworing show_stack() on all architectures in order to be able to pass and use log level and I'm wondering if it's something people will find useful for other uses. -- Aristeu