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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 C5751C433F5 for ; Mon, 13 Sep 2021 07:51:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4B21A60FF2 for ; Mon, 13 Sep 2021 07:51:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4B21A60FF2 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 920F46B0071; Mon, 13 Sep 2021 03:51:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8D18A900002; Mon, 13 Sep 2021 03:51:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 798F96B0073; Mon, 13 Sep 2021 03:51:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0171.hostedemail.com [216.40.44.171]) by kanga.kvack.org (Postfix) with ESMTP id 67E466B0071 for ; Mon, 13 Sep 2021 03:51:42 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 1E61B27756 for ; Mon, 13 Sep 2021 07:51:42 +0000 (UTC) X-FDA: 78581780844.36.E37CB0C Received: from relay.sw.ru (relay.sw.ru [185.231.240.75]) by imf01.hostedemail.com (Postfix) with ESMTP id 82BB5505A649 for ; Mon, 13 Sep 2021 07:51:41 +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=U4RAeSovTvpMRoz+/O0gqhyhiu8Ap3QYy/JuIDY+LGQ=; b=PHISA81fMzX7U1PJK 4jMERB9nGCylx9xhsenaCZO9osLoDfy+1CfYpuXrEUwCyXj1LM98p3ShFPalaRAEU0KAbdr3EP/bC zkLEsPyfEAV5bU5ZBlbuf35U7inCJ5yeA+aSUbManIFFNuT2ACDZhO0e9iicSOvGZT8bz6W5/BN+k =; Received: from [10.93.0.56] by relay.sw.ru with esmtp (Exim 4.94.2) (envelope-from ) id 1mPgkb-001nKw-PH; Mon, 13 Sep 2021 10:51:37 +0300 Subject: Re: [PATCH memcg] memcg: prohibit unconditional exceeding the limit of dying tasks From: Vasily Averin To: Michal Hocko , Johannes Weiner , Vladimir Davydov , Andrew Morton , Tetsuo Handa Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <5b06a490-55bc-a6a0-6c85-690254f86fad@virtuozzo.com> Message-ID: <8b98d44a-aeb2-5f5f-2545-ac2bd0c7049b@virtuozzo.com> Date: Mon, 13 Sep 2021 10:51:37 +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: <5b06a490-55bc-a6a0-6c85-690254f86fad@virtuozzo.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=virtuozzo.com header.s=relay header.b=PHISA81f; spf=pass (imf01.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-Stat-Signature: sg3r3fdtau5i36dt8xgj1srj7w7z3w67 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 82BB5505A649 X-HE-Tag: 1631519501-950570 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 3:39 PM, Vasily Averin wrote: > The kernel currently allows dying tasks to exceed the memcg limits. > The allocation is expected to be the last one and the occupied memory > will be freed soon. > This is not always true because it can be part of the huge vmalloc > allocation. Allowed once, they will repeat over and over again. > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 389b5766e74f..67195fcfbddf 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2622,15 +2625,6 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, > if (gfp_mask & __GFP_ATOMIC) > goto force; > > - /* > - * Unlike in global OOM situations, memcg is not in a physical > - * memory shortage. Allow dying and OOM-killed tasks to > - * bypass the last charges so that they can exit quickly and > - * free their memory. > - */ > - if (unlikely(should_force_charge())) > - goto force; > - Should we keep current behaviour for (current->flags & PF_EXITING) case perhaps? It is set inside do_exit only and (I hope) cannot trigger huge vmalloc allocations. Thank you, Vasily Averin