Received: by 2002:a05:6a10:17d3:0:0:0:0 with SMTP id hz19csp352757pxb; Wed, 14 Apr 2021 17:34:52 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzL9V6GRt//SpWBpOGiy47wovNXx683BoFVafV8iNBa/nfG3ZGu0RFzBta6p4/Yoozexn8G X-Received: by 2002:a17:906:2b94:: with SMTP id m20mr689009ejg.297.1618446892636; Wed, 14 Apr 2021 17:34:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1618446892; cv=none; d=google.com; s=arc-20160816; b=X7MlkxjZsztBpWfevketWfqtgV94JnU5MzCmMvo4n8nnxyY3zxVUSawVs2kLB47+A8 6vIbzN9seh9/Wykek/6lXiJ3v7Z0RlxikA8q/zpF8EdbOHPfVEi0jcb4mwKeYnLvbX9C LYIOzFcxTOCsbCXcnTXwlzFUhBt4zMVhAyK4g3znYBK7J80+ECcQldG1y0jKdjKiq+Gn ksOZUsgQlT5Bh+hmqQI2FXokiCeas38+MLihcgKOrAOwjlwoRrVQ0fFe7ynkKd9QJCvn +aaTvvG2dB9GVxd6oVDxHkabJGMO8kfh0Jy+ip/qWIJFIvn6ztavkQSzW6y/7qAs8A07 f+RQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:ironport-sdr:ironport-sdr; bh=x8MIQDo5u4nLqxGMIRAJdrL35FUXkNA12Nb6ksbwxL8=; b=B7n8fnouzpyg0CfTwffsqzxqQiP0fUe6JFpYTzKyDqUfDolHNSnKCwTUYgjU72kCJs XSyxry+9DHpdZKJK/VMOWglco8EVCJf50oUtxTIJAM02nDr1O2H1cLTtn95DJC7ZvA8b mI+PF26I6ez2Xz+NRw9lc5M6gVFtVUvxcaVrQXZZ3eeb5HcUewoccn+TQbKbaGV5HXay i775Tv2qr96eASk4gJG6II5URkSy1HpQGZsnRS81eu40/1sMObU16dP+g+pr3+m8aRVs QqyXhAwacBBtttVYNlHhDVaiYExQXPq5zUB8X2rndEjrGdKM4IfTqQuHkThKw81Y3SPP cpBg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id hs11si883367ejc.429.2021.04.14.17.34.28; Wed, 14 Apr 2021 17:34:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352535AbhDNPyA (ORCPT + 99 others); Wed, 14 Apr 2021 11:54:00 -0400 Received: from mga05.intel.com ([192.55.52.43]:37711 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350935AbhDNPxN (ORCPT ); Wed, 14 Apr 2021 11:53:13 -0400 IronPort-SDR: exIqsgTeLUJrbtK/MAX3IOxwrC88OPT/B4DSCmK881cfQb/Iy1wG2QfEyLmPPhKA0F2yzukTza nAyWrIr2hXPA== X-IronPort-AV: E=McAfee;i="6200,9189,9954"; a="279979844" X-IronPort-AV: E=Sophos;i="5.82,222,1613462400"; d="scan'208";a="279979844" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2021 08:51:32 -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 Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > 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=y. 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