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=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 6AAE5C433FE for ; Mon, 13 Sep 2021 07:51:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5485560FDA for ; Mon, 13 Sep 2021 07:51:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237789AbhIMHw6 (ORCPT ); Mon, 13 Sep 2021 03:52:58 -0400 Received: from relay.sw.ru ([185.231.240.75]:52358 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237739AbhIMHw4 (ORCPT ); Mon, 13 Sep 2021 03:52:56 -0400 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: Re: [PATCH memcg] memcg: prohibit unconditional exceeding the limit of dying tasks Date: Mon, 13 Sep 2021 10:51:37 +0300 Message-ID: <8b98d44a-aeb2-5f5f-2545-ac2bd0c7049b@virtuozzo.com> References: <5b06a490-55bc-a6a0-6c85-690254f86fad@virtuozzo.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: 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 =; In-Reply-To: <5b06a490-55bc-a6a0-6c85-690254f86fad-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org> Content-Language: en-US List-ID: Content-Type: text/plain; charset="us-ascii" To: Michal Hocko , Johannes Weiner , Vladimir Davydov , Andrew Morton , Tetsuo Handa Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org 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