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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 3535BC432C0 for ; Wed, 27 Nov 2019 01:16:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C1A732071E for ; Wed, 27 Nov 2019 01:16:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PC5raCcF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C1A732071E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 121626B0341; Tue, 26 Nov 2019 20:16:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0D2E46B0342; Tue, 26 Nov 2019 20:16:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EDD1F6B0344; Tue, 26 Nov 2019 20:16:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id D707A6B0341 for ; Tue, 26 Nov 2019 20:16:57 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 89C35181AEF1A for ; Wed, 27 Nov 2019 01:16:57 +0000 (UTC) X-FDA: 76200293274.28.shoes02_3cb66f3fb8211 X-HE-Tag: shoes02_3cb66f3fb8211 X-Filterd-Recvd-Size: 3923 Received: from mail-il1-f194.google.com (mail-il1-f194.google.com [209.85.166.194]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Wed, 27 Nov 2019 01:16:57 +0000 (UTC) Received: by mail-il1-f194.google.com with SMTP id p6so19532197ilp.1 for ; Tue, 26 Nov 2019 17:16:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RTtH9UQFA4MtaV85ad7PLpW4fMGgoLpPFjm5YJ8L7HU=; b=PC5raCcFBDLX6pDGwL2KyynmZxhup+lST9SPmR7LVegKhB9h+CELmrtHw9XExc/G3p 2oQLCV48xbMnfRUg9y+TwAWo3cfg2vn+5LLxwB75rTQ/wEzrQ5z1DAl1re79eziGCeYK ipiscpTqdMk4DR+6xvHSn2mN4HiTopboWmxGcV3+JS7/9kRuBXEmBJ0VPfgkpNZ9PTbh 28UeVGU+USbqGa30mbM5h4HJWWA4uU/CsK3IZst7X1kybTF8njsnISleA/XWDqA5OhCE t69DnE5Tk+RfcdQR6kY8/+1KJ3xzr+7fxUWotSLEwfY25Z0zbMGraxOXlVtH2HyHyHmX vA/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RTtH9UQFA4MtaV85ad7PLpW4fMGgoLpPFjm5YJ8L7HU=; b=CMPj7wEAGYkr52tmBpjKigoJKbUmUC1aW9vQp54c7A/mqoVtLsUBldvNBr3dF23P2c 8P/O8cJzpXnkvm6lgpbInWLSwEuA6k0/ijmUIJr/swgRhEJhJ4hOC6x0+lkHU2oHcF7/ 3nJNMfu8Ol0i8FUT2d3xyi05iqcnM72PRxEfkZSKer01H98Lg7eO+syQF94fYSzybfjz WgmI5Oe+8o4CIP2uTJHux1xjxdMHP/FTh9gU+EfV+Uxmg8IxdEsSJRrt0KUCgG+xjg9I AroqiUE+5U79/mb6Af8vmjpz/lUGw9K3JhQX8nGwqSrRFP1+zJsungKbF8K/t34gDVne 1p8Q== X-Gm-Message-State: APjAAAXUnGHq0Gg8PuSKIpDf89ZA3elW2xwh9xtyzowNASYzEC9WehB4 U1aFrJJ59G/YmxcWZaOICgZkRGQ3KfNJDlRbhLs= X-Google-Smtp-Source: APXvYqw9TIUR9R2d+9tetg9rpK96jcXujPgSWkFOJvIeTPp0vNvEqFb9qcZhWdm3UtbXUhV/L4ZIZdp7IrIUSJiblYc= X-Received: by 2002:a92:109c:: with SMTP id 28mr41444819ilq.142.1574817416400; Tue, 26 Nov 2019 17:16:56 -0800 (PST) MIME-Version: 1.0 References: <1574773369-1634-1-git-send-email-laoar.shao@gmail.com> <20191126163016.GB609004@cmpxchg.org> In-Reply-To: <20191126163016.GB609004@cmpxchg.org> From: Yafang Shao Date: Wed, 27 Nov 2019 09:16:21 +0800 Message-ID: Subject: Re: [PATCH] mm, memcg: avoid oom if cgroup is not populated To: Johannes Weiner Cc: Michal Hocko , Vladimir Davydov , Andrew Morton , Linux MM , Michal Hocko Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000016, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Nov 27, 2019 at 12:30 AM Johannes Weiner wrote: > > On Tue, Nov 26, 2019 at 08:02:49AM -0500, Yafang Shao wrote: > > There's one case that the processes in a memcg are all exit (due to OOM > > group or some other reasons), but the file page caches are still exist. > > These file page caches may be protected by memory.min so can't be > > reclaimed. If we can't success to restart the processes in this memcg or > > don't want to make this memcg offline, then we want to drop the file page > > caches. > > The advantage of droping this file caches is it can avoid the reclaimer > > (either kswapd or direct) scanning and reclaiming pages from all memcgs > > exist in this system, because currently the reclaimer will fairly reclaim > > pages from all memcgs if the system is under memory pressure. > > The possible method to drop these file page caches is setting the > > hard limit of this memcg to 0. Unfortunately this may invoke the OOM killer > > and generates lots of misleading outputs, that should not happen. > > You can set memory.high instead...? Well, I will take a look at memory.high and analye whether it is reliable. Thanks Yafang