From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id 9C2DC6B0038 for ; Mon, 25 Sep 2017 10:23:57 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id b9so9248040wra.3 for ; Mon, 25 Sep 2017 07:23:57 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id k13si5600577edl.288.2017.09.25.07.23.56 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 25 Sep 2017 07:23:56 -0700 (PDT) Date: Mon, 25 Sep 2017 16:23:52 +0200 From: Michal Hocko Subject: Re: [PATCH 0/2 v4] oom: capture unreclaimable slab info in oom message when kernel panic Message-ID: <20170925142352.havlx6ikheanqyhj@dhcp22.suse.cz> References: <1505947132-4363-1-git-send-email-yang.s@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1505947132-4363-1-git-send-email-yang.s@alibaba-inc.com> Sender: owner-linux-mm@kvack.org List-ID: To: Yang Shi Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu 21-09-17 06:38:50, Yang Shi wrote: > Recently we ran into a oom issue, kernel panic due to no killable process. > The dmesg shows huge unreclaimable slabs used almost 100% memory, but kdump doesn't capture vmcore due to some reason. > > So, it may sound better to capture unreclaimable slab info in oom message when kernel panic to aid trouble shooting and cover the corner case. > Since kernel already panic, so capturing more information sounds worthy and doesn't bother normal oom killer. > > With the patchset, tools/vm/slabinfo has a new option, "-U", to show unreclaimable slab only. > > And, oom will print all non zero (num_objs * size != 0) unreclaimable slabs in oom killer message. Well, I do undestand that this _might_ be useful but it also might generates a _lot_ of output. The oom report can be quite verbose already so is this something we want to have enabled by default? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org