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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 A13DBC3F2D1 for ; Fri, 28 Feb 2020 04:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7666C246A1 for ; Fri, 28 Feb 2020 04:03:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="E/VnF2uy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730862AbgB1EDN (ORCPT ); Thu, 27 Feb 2020 23:03:13 -0500 Received: from mail-pj1-f68.google.com ([209.85.216.68]:36601 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730736AbgB1EDM (ORCPT ); Thu, 27 Feb 2020 23:03:12 -0500 Received: by mail-pj1-f68.google.com with SMTP id gv17so722092pjb.1 for ; Thu, 27 Feb 2020 20:03:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=n06LPF76AGlFyu3px3XA7keYv9Nj0np/EAZ7d2DaCjk=; b=E/VnF2uyJTkB+VM5CNaV5k0gccIMZAi3b3mcDfzYqsYfIoZ63P1LHZFJpO2Goiv8MX gFMRgrh4f3tV6czHNvtZfkGCdeJhu9xp/62UtHLQUxC75KIzHA5Jlr9GfG49FdvStlLF L5Qpm7CXg6odc9iYpa0wxXJ8bDOAI5PUznqNj41wsFYE/0B3XO/uMfBkpJJguq2pMXTX PClxs4RQEFCearSfKiNoXelt/3EWBTCWvXr6sthJh9WU9Y+/IFvhqC3g+xC01C74ltu2 5VmkOgYrvCq3gxdz+JB9I1s1xAzPZPGtG/iYFWFWW/GYdmPJGESTD6kyyWoSHU5fifyo Ss6Q== 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:in-reply-to:user-agent; bh=n06LPF76AGlFyu3px3XA7keYv9Nj0np/EAZ7d2DaCjk=; b=nCAhbfIUEGlN/Eim6/quyjJdABnFlPexTx7LsNScgsrrIaWRwxVoHkPlMygThiTypT oDZwfxN6L7410a37A+FBAeQBWj9sEYG+gjd2BiCZ/ERcr+bnoaAIRZi/Jh8S89x+mxvX v0Zwr0RovuaGcYVb3BpsB3uijytBPNSI82FuaxeUFdjDGTeSOVj6Tlu+p/VeodkSUERq O164uTjZWTdy7sGgBz1U1p/EkXNf0jj0qx0xFk8FtbZZ+YX2LHquhUWECgvPNrqZFI5g KutC0vMIkYLWvT5tbBroUbT3tLYwe/Vzn/jzWCltAWmsLc0tuIpBgpImXSwGmw/30UjP Pm6w== X-Gm-Message-State: APjAAAWI0LApEBv0vE81RGo9uI6EYOmpw3Lhwu0XTLTtoNJpZhmcaUM7 gS3t3CyzfC/Ah41I03M2Vqs= X-Google-Smtp-Source: APXvYqyzsTaCPNcK0kE9GMAKVJzjfmXwp/cufCznytHLEzdjK8vt+n6gEuIHuExc4F3uSt6/RR3Y1Q== X-Received: by 2002:a17:902:264:: with SMTP id 91mr2138284plc.335.1582862591643; Thu, 27 Feb 2020 20:03:11 -0800 (PST) Received: from js1304-desktop ([114.206.198.176]) by smtp.gmail.com with ESMTPSA id u7sm8640380pfh.128.2020.02.27.20.03.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Feb 2020 20:03:11 -0800 (PST) Date: Fri, 28 Feb 2020 13:03:03 +0900 From: Joonsoo Kim To: Aaron Lu Cc: Johannes Weiner , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Hugh Dickins , Minchan Kim , Vlastimil Babka , Mel Gorman , kernel-team@lge.com Subject: Re: [PATCH v2 0/9] workingset protection/detection on the anonymous LRU list Message-ID: <20200228040214.GA21040@js1304-desktop> References: <1582175513-22601-1-git-send-email-iamjoonsoo.kim@lge.com> <20200226193942.30049da9c090b466bdc5ec23@linux-foundation.org> <20200227134806.GC39625@cmpxchg.org> <20200228032358.GB634650@ziqianlu-desktop.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200228032358.GB634650@ziqianlu-desktop.localdomain> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Fri, Feb 28, 2020 at 11:23:58AM +0800, Aaron Lu wrote: > On Thu, Feb 27, 2020 at 08:48:06AM -0500, Johannes Weiner wrote: > > On Wed, Feb 26, 2020 at 07:39:42PM -0800, Andrew Morton wrote: > > > It sounds like the above simple aging changes provide most of the > > > improvement, and that the workingset changes are less beneficial and a > > > bit more risky/speculative? > > > > > > If so, would it be best for us to concentrate on the aging changes > > > first, let that settle in and spread out and then turn attention to the > > > workingset changes? > > > > Those two patches work well for some workloads (like the benchmark), > > but not for others. The full patchset makes sure both types work well. > > > > Specifically, the existing aging strategy for anon assumes that most > > anon pages allocated are hot. That's why they all start active and we > > then do second-chance with the small inactive LRU to filter out the > > few cold ones to swap out. This is true for many common workloads. > > > > The benchmark creates a larger-than-memory set of anon pages with a > > flat access profile - to the VM a flood of one-off pages. Joonsoo's > > test: swap-w-rand-mt, which is a multi thread swap write intensive > workload so there will be swap out and swap ins. > > > first two patches allow the VM to usher those pages in and out of > > Weird part is, the robot says the performance gain comes from the 1st > patch only, which adjust the ratio, not including the 2nd patch which > makes anon page starting from inactive list. > > I find the performance gain hard to explain... Let me explain the reason of the performance gain. 1st patch provides more second chance to the anonymous pages. In swap-w-rand-mt test, memory used by all threads is greater than the amount of the system memory, but, memory used by each thread would not be much. So, although it is a rand test, there is a locality in each thread's job. More second chance helps to exploit this locality so performance could be improved. Thanks.