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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 A9DB6C433E1 for ; Tue, 18 Aug 2020 10:04:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F63F20786 for ; Tue, 18 Aug 2020 10:04:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Ec+Zcl4x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726336AbgHRKE7 (ORCPT ); Tue, 18 Aug 2020 06:04:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726043AbgHRKE6 (ORCPT ); Tue, 18 Aug 2020 06:04:58 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EF99C061389; Tue, 18 Aug 2020 03:04:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=pE8vmQW7SZy0+JnQJV6um55H7ktisT4GBi3Ij24COKw=; b=Ec+Zcl4xLw+ZX6xKNyn+LxSmLG EZ0TRWdmzTaNznp3475KXmL3ObxYB8nifTSAaMXiLeZUks0Nj5dKNXO1Xn7KLLyXdVmocwwsjI4lS vle42FQMDNCGwBA718/gxyq2awU9AUycF2AWtY7YvO2anUpmOw2nxD9NNLylDwT1Y8AgDnFt0tIMK aXjKb+XCYELLhPQAQvh3b4tpgmLWW2qDfIU9Sookz16wBzOHVP9oWOoFLBkp/Z9O3ds+gd5jHL6Rv yKky0b51qKBgFHHFuKF0rKJf3lONp/eBNtXBzBQs52mYwF+8Rn0gH3SW7XRRift4xDJ6wOYiRrsi7 klLCmhAg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k7yU0-00009c-R9; Tue, 18 Aug 2020 10:04:45 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 48FD9301179; Tue, 18 Aug 2020 12:04:44 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2F8A722E9BD47; Tue, 18 Aug 2020 12:04:44 +0200 (CEST) Date: Tue, 18 Aug 2020 12:04:44 +0200 From: peterz@infradead.org To: Chris Down Cc: Waiman Long , Andrew Morton , Johannes Weiner , Michal Hocko , 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: <20200818100444.GN2674@hirez.programming.kicks-ass.net> References: <20200817140831.30260-1-longman@redhat.com> <20200818091453.GL2674@hirez.programming.kicks-ass.net> <20200818092737.GA148695@chrisdown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200818092737.GA148695@chrisdown.name> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, Aug 18, 2020 at 10:27:37AM +0100, Chris Down wrote: > peterz@infradead.org writes: > > 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. > > We already do that since v5.4. I'm wondering whether Waiman's customer is > just running with a too-old kernel without 0e4b01df865 ("mm, memcg: throttle > allocators when failing reclaim over memory.high") backported. That commit is fundamentally broken, it doesn't guarantee anything. Please go read how the dirty throttling works (unless people wrecked that since..).