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=-2.5 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B6C4CC432C2 for ; Wed, 25 Sep 2019 06:52:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 904E3217F4 for ; Wed, 25 Sep 2019 06:52:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 904E3217F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E28C16B0279; Wed, 25 Sep 2019 02:52:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD9B46B027A; Wed, 25 Sep 2019 02:52:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CEF426B027B; Wed, 25 Sep 2019 02:52:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0178.hostedemail.com [216.40.44.178]) by kanga.kvack.org (Postfix) with ESMTP id AE3766B0279 for ; Wed, 25 Sep 2019 02:52:53 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 5902F181AC9B4 for ; Wed, 25 Sep 2019 06:52:53 +0000 (UTC) X-FDA: 75972525426.08.brake83_36472b703fb0e X-HE-Tag: brake83_36472b703fb0e X-Filterd-Recvd-Size: 2253 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Wed, 25 Sep 2019 06:52:52 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 49E1FB044; Wed, 25 Sep 2019 06:52:51 +0000 (UTC) Date: Wed, 25 Sep 2019 08:52:48 +0200 From: Michal Hocko To: Hillf Danton Cc: Roman Gushchin , Johannes Weiner , Andrew Morton , linux , linux-mm , Shakeel Butt , Matthew Wilcox Subject: Re: [RFC] mm: memcg: add priority for soft limit reclaiming Message-ID: <20190925065248.GF23050@dhcp22.suse.cz> References: <20190924073642.3224-1-hdanton@sina.com> <20190924133016.GT23050@dhcp22.suse.cz> <20190925023530.6364-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190925023530.6364-1-hdanton@sina.com> User-Agent: Mutt/1.10.1 (2018-07-13) 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 Wed 25-09-19 10:35:30, Hillf Danton wrote: > > On Tue, 24 Sep 2019 17:23:35 +0000 from Roman Gushchin > > > > On Tue, Sep 24, 2019 at 03:30:16PM +0200, Michal Hocko wrote: > > > > > > But really, make sure you look into the existing feature set that memcg > > > v2 provides already and come back if you find it unsuitable and we can > > > move from there. Soft limit reclaim is dead and we should let it RIP. > > > > Can't agree more here. > > > > Cgroup v2 memory protection mechanisms (memory.low/min) should perfectly > > solve the described problem. If not, let's fix them rather than extend soft > > reclaim which is already dead. > > > Hehe, IIUC memory.low/min is essentially drawing a line that reclaimers > would try their best not to cross. Page preemption OTOH is near ten miles > away from that line though it is now on the shoulder of soft reclaiming. Dynamic low limit tuning would achieve exactly what you are after - aka prioritizing some memory consumers over others. -- Michal Hocko SUSE Labs