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 3A78EC433E1 for ; Tue, 18 Aug 2020 12:56:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BD3102076D for ; Tue, 18 Aug 2020 12:56:16 +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="pUGj2Ixn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD3102076D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EF7186B0010; Tue, 18 Aug 2020 08:56:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EA69C8D0001; Tue, 18 Aug 2020 08:56:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D6E146B0025; Tue, 18 Aug 2020 08:56:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0167.hostedemail.com [216.40.44.167]) by kanga.kvack.org (Postfix) with ESMTP id BEBAE6B0010 for ; Tue, 18 Aug 2020 08:56:15 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 8586C1F08 for ; Tue, 18 Aug 2020 12:56:15 +0000 (UTC) X-FDA: 77163687510.27.hat20_29081d62701f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin27.hostedemail.com (Postfix) with ESMTP id 5590A3D669 for ; Tue, 18 Aug 2020 12:56:15 +0000 (UTC) X-HE-Tag: hat20_29081d62701f X-Filterd-Recvd-Size: 3804 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Tue, 18 Aug 2020 12:56:14 +0000 (UTC) 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=Mnr9o5vomenMnjGSwOgADsZNSiDQs16XxuJQkA6pw7A=; b=pUGj2IxnkHV9vZueIpbwqji2Jz 4osZe4zjTl6vy8j4O1GqSzuht1xZTlDq/nyo7Zt88MLI0EF3+bRsp7khSHVkul6jXPUt6jbUcGgqX wB2TcbFBTZRD44Iz4OBsNLp9tT2pWHDXZxgDCYE1sqJxFC8/2qUdR7Gr5kHMA+fihdG3Xd3EPQgs3 1Yi3ukQgtyCHWgNKqxRmqGQFa7YJ77FBhxgwcSBJ0sTftYxwm0Zr5Kz0hFwQ+NrV3N+Gfdg3tiPoG TFHH6wJpI5/01cnU9Z5jhHgml1eM1Aji19CV+ORA8lxPNw/zaz+KJse0bAZLt4mKIZPP3ziA3p9kW bOdS3v4g==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k819j-0001m3-9N; Tue, 18 Aug 2020 12:55:59 +0000 Date: Tue, 18 Aug 2020 13:55:59 +0100 From: Matthew Wilcox To: peterz@infradead.org Cc: Chris Down , 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: <20200818125559.GP17456@casper.infradead.org> References: <20200817140831.30260-1-longman@redhat.com> <20200818091453.GL2674@hirez.programming.kicks-ass.net> <20200818092737.GA148695@chrisdown.name> <20200818100444.GN2674@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200818100444.GN2674@hirez.programming.kicks-ass.net> X-Rspamd-Queue-Id: 5590A3D669 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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 Tue, Aug 18, 2020 at 12:04:44PM +0200, peterz@infradead.org wrote: > 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..). Of course they did. https://lore.kernel.org/linux-mm/ce7975cd-6353-3f29-b52c-7a81b1d07caa@kernel.dk/