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 D8675C433ED for ; Wed, 14 Apr 2021 15:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9FA661164 for ; Wed, 14 Apr 2021 15:59:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352754AbhDNP7m (ORCPT ); Wed, 14 Apr 2021 11:59:42 -0400 Received: from shelob.surriel.com ([96.67.55.147]:56010 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352707AbhDNP7k (ORCPT ); Wed, 14 Apr 2021 11:59:40 -0400 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lWhuo-0000xe-34; Wed, 14 Apr 2021 11:58:54 -0400 Message-ID: Subject: Re: [PATCH v2 00/16] Multigenerational LRU Framework From: Rik van Riel To: Andi Kleen , Yu Zhao Cc: 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 Date: Wed, 14 Apr 2021 11:58:53 -0400 In-Reply-To: <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> <20210414155130.GU3762101@tassilo.jf.intel.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-fqISq52dkvESve12W123" User-Agent: Evolution 3.34.4 (3.34.4-1.fc31) MIME-Version: 1.0 Sender: riel@shelob.surriel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-fqISq52dkvESve12W123 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2021-04-14 at 08:51 -0700, Andi Kleen wrote: > > 2) It will not scan PTE tables under non-leaf PMD entries that > > do not > > have the accessed bit set, when > > CONFIG_HAVE_ARCH_PARENT_PMD_YOUNG=3Dy. >=20 > 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? Databases with large shared memory segments shared between many processes come to mind as a real-world example of a worst case scenario. --=20 All Rights Reversed. --=-fqISq52dkvESve12W123 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAmB3ET0ACgkQznnekoTE 3oOWmwf+NLdHxOkMEfUsaCu0VliS0AtOhRW/rs6xlDeVVKUN1ZUu0EWq090tsEmu 9HorztY9517iMoQG4aSewE5eFdoTA4DznUS9MU3E/7esp9Sw6zbQlg1wHif/Cc/w qojnfuEvA4tjCZXiUKWJA/qpsvSRmr4tXhmZeJYhBw/V78WJTq0cZ1YKWhuJ+wu7 yeQ9lmt7FY371wa38hHGZ0B5aZqKfXqI4boaRApkVBz3KK4pATQCe7kI3lH0TY8+ XS/9h5DHgz5DaovC2P5LRwmZQG9ZZqytNPy4cYgCt9SSg/jFWRMKM7XnobVHIhsq zqMi/EQUXy/bnnHNHR5q8CcsjrZmfA== =GWQL -----END PGP SIGNATURE----- --=-fqISq52dkvESve12W123--