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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 75C3CC2D0C0 for ; Thu, 19 Dec 2019 11:26:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C06621D7D for ; Thu, 19 Dec 2019 11:26:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b="Nj6BUQEZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726769AbfLSL0W (ORCPT ); Thu, 19 Dec 2019 06:26:22 -0500 Received: from mail-wr1-f68.google.com ([209.85.221.68]:42820 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726652AbfLSL0W (ORCPT ); Thu, 19 Dec 2019 06:26:22 -0500 Received: by mail-wr1-f68.google.com with SMTP id q6so5574988wro.9 for ; Thu, 19 Dec 2019 03:26:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=ZxINuY2pTedRL5AOR8tT78C1M2jclzElPJ7W9Ytee4A=; b=Nj6BUQEZ+CRfeqS8i/TOUwhdSD/LqqktFae+t7JfgDcNBTv07sDWW+AN6qK4jJxq2b bD96kwCBm+NCxbmhwMq95YWUG6nwJtQUz+B0gWcpUboDbYAvGxtqalmKIIDrPQsdQakD 0vumq1+lukQ7gHQ8kRlgoND+EH8XGHRzhB5Qw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=ZxINuY2pTedRL5AOR8tT78C1M2jclzElPJ7W9Ytee4A=; b=cZDuipcvMvuNnfuH5Lg/uqIzmQg8MlbOuhsRl2wiXmWwoRzkvrZTQud5SFijepHj4N RobNjXbd4SEJOX9DDhmE9DGtng29O3eDeHMJTASiN5Qgm6Lg86BSLBO/W9aaRMZcLfUH AvwraUuO9oGEUwegd9AFA5uWn87I+PyI8/XpXSCNnXNNwCKYJasgQa+65S3Hcv3Fj1xz 3ScitI/jEgKr0I+biA8BWRrATVKcqKro7Gf9VXvAvoqAmftCwAzyC7n4RV4S2pdRKhXX WOAzOjyCw0RAiTJI1MXFcByVsA8SMZEubiqTgymmJNtvGtN2MRjqadfVZkKkPkkAVkdA zjQw== X-Gm-Message-State: APjAAAX5dpj2uPeCJYaUWayAoj+nkeIH1pkgIQPFj5s7BOOdM31igA9J Ig5qU9vP+4QHXqZFCZ2aeufDXw== X-Google-Smtp-Source: APXvYqzYYXrskQ1fe2mPfv0sYrehg6SOYYoZVfiW64/lsm4OI0an3dqEGvYMZJ/Hh5HOscaWldIplg== X-Received: by 2002:a05:6000:12ce:: with SMTP id l14mr9363595wrx.342.1576754779511; Thu, 19 Dec 2019 03:26:19 -0800 (PST) Received: from localhost ([2620:10d:c092:200::1:c2e5]) by smtp.gmail.com with ESMTPSA id a16sm6039042wrt.37.2019.12.19.03.26.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Dec 2019 03:26:18 -0800 (PST) Date: Thu, 19 Dec 2019 11:26:18 +0000 From: Chris Down To: teawater Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, guro@fb.com, shakeelb@google.com, Yang Shi , tj@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm: vmscan: memcg: Add global shrink priority Message-ID: <20191219112618.GA72828@chrisdown.name> References: <1576662179-16861-1-git-send-email-teawaterz@linux.alibaba.com> <20191218140952.GA255739@chrisdown.name> <25AA9500-B249-42C2-B162-2B8D4EE83BB0@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <25AA9500-B249-42C2-B162-2B8D4EE83BB0@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hui, teawater writes: >Memory.min, low, high can affect the global shrink behavior. They can help >task keep some pages to help protect performance. > >But what I want is the low priority tasks (the tasks that performance is not >very important) do more shrink first. And when low priority tasks doesn’t >have enough pages to be dropped and system need more free page, shrink the >high priority task’s pages. Because at this time, system’s stable is more >important than the performance of priority task. >With memory.min and memory.low, I have no idea to config them to support this. >That is why I add global shrink priority. For sure, that's what I'm suggesting you use memory.{min,low} for -- you define some subset of the cgroup hierarchy as "protected", and then you bias reclaim away from protected cgroups (and thus *towards* unprotected cgroups) by biasing the size of LRU scanning. See my patch that went into 5.4 and the examples in the commit message: commit 9783aa9917f8ae24759e67bf882f1aba32fe4ea1 Author: Chris Down Date: Sun Oct 6 17:58:32 2019 -0700 mm, memcg: proportional memory.{low,min} reclaim You can see how we're using memory.{low,min} to achieve this in this case study[0]. It's not exactly equivalent technically to your solution, but the end goals are similar. Thanks, Chris 0: https://facebookmicrosites.github.io/cgroup2/docs/overview.html#case-study-the-fbtax2-project