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 7DC4DC433B4 for ; Wed, 14 Apr 2021 15:51:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 05CD860238 for ; Wed, 14 Apr 2021 15:51:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 05CD860238 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 96A578D0001; Wed, 14 Apr 2021 11:51:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 941CC6B0082; Wed, 14 Apr 2021 11:51:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 80B168D0001; Wed, 14 Apr 2021 11:51:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0251.hostedemail.com [216.40.44.251]) by kanga.kvack.org (Postfix) with ESMTP id 63E446B0080 for ; Wed, 14 Apr 2021 11:51:35 -0400 (EDT) Received: from smtpin32.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 1D2F333CD for ; Wed, 14 Apr 2021 15:51:35 +0000 (UTC) X-FDA: 78031412550.32.E6F759B Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by imf12.hostedemail.com (Postfix) with ESMTP id 914C9F6 for ; Wed, 14 Apr 2021 15:51:28 +0000 (UTC) IronPort-SDR: hJgZVcBk6ev7U/d7wH0+QJaG/tSbcwpZMKkDa0IOjeJn7VxxTM1ZmsrjjLfDVuaYYpNu50Hlxu H3Nj9FFrgGYg== X-IronPort-AV: E=McAfee;i="6200,9189,9954"; a="194776987" X-IronPort-AV: E=Sophos;i="5.82,222,1613462400"; d="scan'208";a="194776987" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2021 08:51:31 -0700 IronPort-SDR: XIVu+S/eRyaGWRdU1FaHTPNytGmcRAh9mWp1bQiFCttzqGk7tZPEjSWJk03ABIP8GUytCn+UCh KdnCJKtrT0cQ== X-IronPort-AV: E=Sophos;i="5.82,222,1613462400"; d="scan'208";a="424790149" Received: from tassilo.jf.intel.com ([10.54.74.11]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2021 08:51:31 -0700 Date: Wed, 14 Apr 2021 08:51:30 -0700 From: Andi Kleen To: Yu Zhao Cc: Rik van Riel , Dave Chinner , Jens Axboe , SeongJae Park , Linux-MM , Andrew Morton , Benjamin Manes , Dave Hansen , Hillf Danton , Johannes Weiner , Jonathan Corbet , Joonsoo Kim , Matthew Wilcox , Mel Gorman , Miaohe Lin , Michael Larabel , Michal Hocko , Michel Lespinasse , Roman Gushchin , Rong Chen , SeongJae Park , Tim Chen , Vlastimil Babka , Yang Shi , Ying Huang , Zi Yan , linux-kernel , lkp@lists.01.org, Kernel Page Reclaim v2 Subject: Re: [PATCH v2 00/16] Multigenerational LRU Framework Message-ID: <20210414155130.GU3762101@tassilo.jf.intel.com> References: <20210413075155.32652-1-sjpark@amazon.de> <3ddd4f8a-8e51-662b-df11-a63a0e75b2bc@kernel.dk> <20210413231436.GF63242@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 914C9F6 X-Stat-Signature: xnj5dqhogpcyrqy18g6fiqmzjri5e3cd Received-SPF: none (linux.intel.com>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=mga09.intel.com; client-ip=134.134.136.24 X-HE-DKIM-Result: none/none X-HE-Tag: 1618415488-894846 Content-Transfer-Encoding: quoted-printable 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: > 2) It will not scan PTE tables under non-leaf PMD entries that do no= t > =A0 =A0have the accessed bit set, when > =A0 =A0CONFIG_HAVE_ARCH_PARENT_PMD_YOUNG=3Dy. This assumes that workloads have reasonable locality. Could there be a worst case where only one or two pages in each PTE are used, so this PTE skipping trick doesn't work? -Andi