From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752324AbaFEP4A (ORCPT ); Thu, 5 Jun 2014 11:56:00 -0400 Received: from a.ns.miles-group.at ([95.130.255.143]:47834 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751588AbaFEPz6 (ORCPT ); Thu, 5 Jun 2014 11:55:58 -0400 Message-ID: <5390930A.8050504@nod.at> Date: Thu, 05 Jun 2014 17:55:54 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Michal Hocko CC: hannes@cmpxchg.org, bsingharora@gmail.com, kamezawa.hiroyu@jp.fujitsu.com, akpm@linux-foundation.org, vdavydov@parallels.com, tj@kernel.org, handai.szj@taobao.com, rientjes@google.com, oleg@redhat.com, rusty@rustcorp.com.au, kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC][PATCH] oom: Be less verbose if the oom_control event fd has listeners References: <1401976841-3899-1-git-send-email-richard@nod.at> <1401976841-3899-2-git-send-email-richard@nod.at> <20140605150025.GB15939@dhcp22.suse.cz> In-Reply-To: <20140605150025.GB15939@dhcp22.suse.cz> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 05.06.2014 17:00, schrieb Michal Hocko: > On Thu 05-06-14 16:00:41, Richard Weinberger wrote: >> Don't spam the kernel logs if the oom_control event fd has listeners. >> In this case there is no need to print that much lines as user space >> will anyway notice that the memory cgroup has reached its limit. > > But how do you debug why it is reaching the limit and why a particular > process has been killed? In my case it's always because customer's Java application gone nuts. So I don't really have to debug a lot. ;-) But I can understand your point. > If we are printing too much then OK, let's remove those parts which are > not that useful but hiding information which tells us more about the oom > decision doesn't sound right to me. What about adding a sysctl like "vm.oom_verbose"? By default it would be 1. If set to 0 the full OOM information is only printed out if nobody listens to the event fd. Thanks, //richard