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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 03745C47E49 for ; Sat, 2 Nov 2019 16:14:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BB7302080F for ; Sat, 2 Nov 2019 16:14:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="Hmd1SS8F" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB7302080F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=yandex-team.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 452F36B0007; Sat, 2 Nov 2019 12:14:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 404B06B0008; Sat, 2 Nov 2019 12:14:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 319C36B000A; Sat, 2 Nov 2019 12:14:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0248.hostedemail.com [216.40.44.248]) by kanga.kvack.org (Postfix) with ESMTP id 144BB6B0007 for ; Sat, 2 Nov 2019 12:14:57 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id B5469813E for ; Sat, 2 Nov 2019 16:14:56 +0000 (UTC) X-FDA: 76111836192.24.beam89_2b05e62e4a125 X-HE-Tag: beam89_2b05e62e4a125 X-Filterd-Recvd-Size: 4083 Received: from forwardcorp1j.mail.yandex.net (forwardcorp1j.mail.yandex.net [5.45.199.163]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Sat, 2 Nov 2019 16:14:55 +0000 (UTC) Received: from mxbackcorp1g.mail.yandex.net (mxbackcorp1g.mail.yandex.net [IPv6:2a02:6b8:0:1402::301]) by forwardcorp1j.mail.yandex.net (Yandex) with ESMTP id A459B2E0DDE; Sat, 2 Nov 2019 19:14:52 +0300 (MSK) Received: from vla1-5826f599457c.qloud-c.yandex.net (vla1-5826f599457c.qloud-c.yandex.net [2a02:6b8:c0d:35a1:0:640:5826:f599]) by mxbackcorp1g.mail.yandex.net (nwsmtp/Yandex) with ESMTP id EyUENoXOa7-EqDSob5x; Sat, 02 Nov 2019 19:14:52 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1572711292; bh=Yd0CleJdEZRkBuzs0TYF6lmKdD5XxhQPGhQbqlbh1rs=; h=In-Reply-To:References:Date:Message-ID:From:To:Subject; b=Hmd1SS8FaLYfXLialvxaRuDNR9z0cBETtPVQqrm55xgu7uifS0HC/9FbkK/S66nMS tdEfmITpnkRcvh1IeWvmV4LHVLiCeitt98Sacehrrtv06CdILIuXHfYN5YP71JEnkV DSJPImoOysWZL0BvYUYmBzfnHJmLy1K01HpixnW8= Authentication-Results: mxbackcorp1g.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:8554:53c0:3d75:2e8a]) by vla1-5826f599457c.qloud-c.yandex.net (nwsmtp/Yandex) with ESMTPSA id VQiFRucw4e-EqVmg9Qb; Sat, 02 Nov 2019 19:14:52 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: Re: [PATCH] mm/memcontrol: update documentation about invoking oom killer To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Michal Hocko References: <157270779336.1961.6528158720593572480.stgit@buzz> <20191102160252.GA19103@freebsd.familie-tometzki.de> From: Konstantin Khlebnikov Message-ID: <5c85a690-4ed7-91bb-30b5-c40174534a27@yandex-team.ru> Date: Sat, 2 Nov 2019 19:14:51 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191102160252.GA19103@freebsd.familie-tometzki.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-CA Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 02/11/2019 19.02, Damian Tometzki wrote: > On Sat, 02. Nov 18:16, 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") >> 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 > Hello Konstantin, > > iff --> if :-) > This "iff" is shortened "if and only if". https://en.wikipedia.org/wiki/If_and_only_if > Best regards > Damian > > >> + 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 >>