From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D125ECA9EC7 for ; Tue, 5 Nov 2019 06:10:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2E25206DF for ; Tue, 5 Nov 2019 06:10:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572934203; bh=W/wYEcEhUMj9+LuKP3n/2z3db2n/GhMcWPGKV0mdCGs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=HEG72Dh5MKJeYpAXgE0jAssBF3b2XjFaSb/ETdytvChYgYaUv9C3Sw7hPpDdeZrQi doXrdo17oWOLOPMvk1te37bel309xwzaXJCLviyWgue5ehwg9zv+iRn2r5TrK3IZBz +e+VPQqubBM12gDZ3NmYtKtKVeTLRZVmOZPITHMU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387607AbfKEGKC (ORCPT ); Tue, 5 Nov 2019 01:10:02 -0500 Received: from mx2.suse.de ([195.135.220.15]:39870 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387454AbfKEGKC (ORCPT ); Tue, 5 Nov 2019 01:10:02 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 75FB4B160; Tue, 5 Nov 2019 06:10:00 +0000 (UTC) Date: Tue, 5 Nov 2019 07:09:59 +0100 From: Michal Hocko To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH] mm/memcontrol: update documentation about invoking oom killer Message-ID: <20191105060959.GA22672@dhcp22.suse.cz> References: <157270779336.1961.6528158720593572480.stgit@buzz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <157270779336.1961.6528158720593572480.stgit@buzz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 02-11-19 18:16:33, Konstantin Khlebnikov wrote: > Since commit 29ef680ae7c2 ("memcg, oom: move out_of_memory back to the > charge path") memcg invokes oom killer not only for user page-faults. > This means 0-order allocation will either succeed or task get killed. > > Fixes: 8e675f7af507 ("mm/oom_kill: count global and memory cgroup oom kills") Is this really appropriate? 8e675f7af507 was correct at the time. It was 29ef680ae7c2 that hasn't updated the documentation. I would just drop the Fixes tag. > Signed-off-by: Konstantin Khlebnikov > --- > Documentation/admin-guide/cgroup-v2.rst | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst > index 5361ebec3361..eb47815e137b 100644 > --- a/Documentation/admin-guide/cgroup-v2.rst > +++ b/Documentation/admin-guide/cgroup-v2.rst > @@ -1219,8 +1219,13 @@ PAGE_SIZE multiple when read back. > > Failed allocation in its turn could be returned into > userspace as -ENOMEM or silently ignored in cases like > - disk readahead. For now OOM in memory cgroup kills > - tasks iff shortage has happened inside page fault. > + disk readahead. > + > + Before 4.19 OOM in memory cgroup killed tasks iff I would go with Kernels between 3.12 and 4.19 invoked the oom killer only if shortage has happened inside page fault. > + shortage has happened inside page fault, random > + syscall may fail with ENOMEM or EFAULT. Since 4.19 > + failed memory cgroup allocation invokes oom killer and > + keeps retrying until it succeeds. > > This event is not raised if the OOM killer is not > considered as an option, e.g. for failed high-order -- Michal Hocko SUSE Labs