From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f197.google.com (mail-ot0-f197.google.com [74.125.82.197]) by kanga.kvack.org (Postfix) with ESMTP id A4D786B0003 for ; Mon, 2 Jul 2018 07:22:15 -0400 (EDT) Received: by mail-ot0-f197.google.com with SMTP id o3-v6so12050007otl.16 for ; Mon, 02 Jul 2018 04:22:15 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id g22-v6si311487ote.339.2018.07.02.04.22.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Jul 2018 04:22:14 -0700 (PDT) Date: Mon, 2 Jul 2018 07:22:13 -0400 (EDT) From: Rodrigo Freire Message-ID: <1113748807.15224076.1530530533122.JavaMail.zimbra@redhat.com> In-Reply-To: <20180702093043.GB19043@dhcp22.suse.cz> References: <7de14c6cac4a486c04149f37948e3a76028f3fa5.1530461087.git.rfreire@redhat.com> <20180702093043.GB19043@dhcp22.suse.cz> Subject: Re: [PATCH] mm: be more informative in OOM task list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Hello Michal, ----- Original Message ----- > From: "Michal Hocko" > To: "Rodrigo Freire" > Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org > Sent: Monday, July 2, 2018 6:30:43 AM > Subject: Re: [PATCH] mm: be more informative in OOM task list > > On Sun 01-07-18 13:09:40, Rodrigo Freire wrote: > > The default page memory unit of OOM task dump events might not be > > intuitive for the non-initiated when debugging OOM events. Add > > a small printk prior to the task dump informing that the memory > > units are actually memory _pages_. > > Does this really help? I understand the the oom report might be not the > easiest thing to grasp but wouldn't it be much better to actually add > documentation with clarification of each part of it? That would be great: After a quick grep -ri for oom in Documentation, I found several other files containing its own OOM behaviour modifier configurations. But it indeed lacks a central and canonical Doc file which documents the OOM Killer behavior and workflows. However, I still stand by my proposed patch: It is unobtrusive, infers no performance issue and clarifying: I recently worked in a case (for full disclosure: I am a far cry from a MM expert) where the sum of the RSS pages made sense when interpreted as real kB pages. Reason: There were processes sharing (a good amount of) memory regions, misleading the interpretation and that misled not only me, but some other colleagues a well: The pages was only sorted out after actually inspecting the source code. This patch is user-friendly and can be a great time saver to others in the community. I kindly request the ACKed-by ;-) Have a great week, - RF.