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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 9DEA9C433F5 for ; Mon, 13 Sep 2021 08:29:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2B35960F12 for ; Mon, 13 Sep 2021 08:29:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2B35960F12 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C053D6B0072; Mon, 13 Sep 2021 04:29:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BB3A06B0073; Mon, 13 Sep 2021 04:29:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AA2C6900002; Mon, 13 Sep 2021 04:29:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0187.hostedemail.com [216.40.44.187]) by kanga.kvack.org (Postfix) with ESMTP id 9E5966B0072 for ; Mon, 13 Sep 2021 04:29:43 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 56945180AD807 for ; Mon, 13 Sep 2021 08:29:43 +0000 (UTC) X-FDA: 78581876646.12.CD17A8B Received: from relay.sw.ru (relay.sw.ru [185.231.240.75]) by imf03.hostedemail.com (Postfix) with ESMTP id E4D6E30000A9 for ; Mon, 13 Sep 2021 08:29:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:From: Subject; bh=hQgKXyWNPvle3hQKqsfae85Qw8UvU0A7uIpON9jfF6c=; b=S66sreVvkhtAHXlkX 3SJin2YhAz6QeFhEq7J7kxn/rGoVZWl2UkW9Eu3DJAfRVRKeHYZoR6NOCDu/WxkuytAfsKdYnQUk1 ZILk96zL8+M9MErZOpzrFJv0js8EdDQdJhzo8qlnfrLleAeUvEbpKSjx5c37qiI4EgHaSkT2AHxzo =; Received: from [10.93.0.56] by relay.sw.ru with esmtp (Exim 4.94.2) (envelope-from ) id 1mPhLO-001nZm-35; Mon, 13 Sep 2021 11:29:38 +0300 Subject: Re: [PATCH memcg] memcg: prohibit unconditional exceeding the limit of dying tasks To: Michal Hocko Cc: Tetsuo Handa , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner , Vladimir Davydov , Andrew Morton References: <5b06a490-55bc-a6a0-6c85-690254f86fad@virtuozzo.com> <099aa0db-045a-e5b8-6df7-b7c3fc4d3caa@i-love.sakura.ne.jp> <4a407474-ff7a-9e4f-d314-ab85f0eeaadf@virtuozzo.com> From: Vasily Averin Message-ID: <9556c2ae-2dc8-9d0a-55de-002d674680bf@virtuozzo.com> Date: Mon, 13 Sep 2021 11:29:37 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=virtuozzo.com header.s=relay header.b=S66sreVv; spf=pass (imf03.hostedemail.com: domain of vvs@virtuozzo.com designates 185.231.240.75 as permitted sender) smtp.mailfrom=vvs@virtuozzo.com; dmarc=pass (policy=quarantine) header.from=virtuozzo.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: E4D6E30000A9 X-Stat-Signature: 96sy5nwpt3gcsuy63u8rnq6kms6ajcbd X-HE-Tag: 1631521782-595902 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 9/10/21 5:55 PM, Michal Hocko wrote: > On Fri 10-09-21 16:20:58, Vasily Averin wrote: >> On 9/10/21 4:04 PM, Tetsuo Handa wrote: >>> Can't we add fatal_signal_pending(current) test to vmalloc() loop? > > We can and we should. > >> 1) this has been done in the past but has been reverted later. > > The reason for that should be addressed IIRC. I don't know the details of this, and I need some time to investigate it. >> 2) any vmalloc changes will affect non-memcg allocations too. >> If we're doing memcg-related checks it's better to do it in one place. > > I think those two things are just orthogonal. Bailing out from vmalloc > early sounds reasonable to me on its own. Allocating a large thing that > is likely to go away with the allocating context is just a waste of > resources and potential reason to disruptions to others. I doubt that fatal signal should block any vmalloc allocations. I assume there are situations where rollback of some cancelled operation uses vmalloc. Or coredump saving on some remote storage can uses vmalloc. However for me it's abnormal that even OOM-killer cannot cancel huge vmalloc allocation. So I think tsk_is_oom_victim(current) check should be added to vm_area_alloc_pages() to break vmalloc cycle. Thank you, Vasily Averin