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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 CF22AC433DF for ; Tue, 18 Aug 2020 10:05:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B95C32065D for ; Tue, 18 Aug 2020 10:05:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726715AbgHRKFT (ORCPT ); Tue, 18 Aug 2020 06:05:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:47112 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726043AbgHRKFT (ORCPT ); Tue, 18 Aug 2020 06:05:19 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3C6F9B12C; Tue, 18 Aug 2020 10:05:43 +0000 (UTC) Date: Tue, 18 Aug 2020 12:05:16 +0200 From: Michal Hocko To: peterz@infradead.org Cc: Waiman Long , Andrew Morton , Johannes Weiner , Vladimir Davydov , Jonathan Corbet , Alexey Dobriyan , Ingo Molnar , Juri Lelli , Vincent Guittot , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH 0/8] memcg: Enable fine-grained per process memory control Message-ID: <20200818100516.GO28270@dhcp22.suse.cz> References: <20200817140831.30260-1-longman@redhat.com> <20200818091453.GL2674@hirez.programming.kicks-ass.net> <20200818092617.GN28270@dhcp22.suse.cz> <20200818095910.GM2674@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200818095910.GM2674@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 18-08-20 11:59:10, Peter Zijlstra wrote: > On Tue, Aug 18, 2020 at 11:26:17AM +0200, Michal Hocko wrote: > > On Tue 18-08-20 11:14:53, Peter Zijlstra wrote: > > > On Mon, Aug 17, 2020 at 10:08:23AM -0400, Waiman Long wrote: > > > > Memory controller can be used to control and limit the amount of > > > > physical memory used by a task. When a limit is set in "memory.high" in > > > > a v2 non-root memory cgroup, the memory controller will try to reclaim > > > > memory if the limit has been exceeded. Normally, that will be enough > > > > to keep the physical memory consumption of tasks in the memory cgroup > > > > to be around or below the "memory.high" limit. > > > > > > > > Sometimes, memory reclaim may not be able to recover memory in a rate > > > > that can catch up to the physical memory allocation rate. In this case, > > > > the physical memory consumption will keep on increasing. > > > > > > Then slow down the allocator? That's what we do for dirty pages too, we > > > slow down the dirtier when we run against the limits. > > > > This is what we actually do. Have a look at mem_cgroup_handle_over_high. > > But then how can it run-away like Waiman suggested? As Chris mentioned in other reply. This functionality is quite new. > /me goes look... and finds MEMCG_MAX_HIGH_DELAY_JIFFIES. We can certainly tune a different backoff delays but I suspect this is not the problem here. > That's a fail... :-( -- Michal Hocko SUSE Labs