From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 5DF996B0038 for ; Wed, 9 Nov 2016 05:33:26 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id 144so70343476pfv.5 for ; Wed, 09 Nov 2016 02:33:26 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id m10si234732paw.24.2016.11.09.02.33.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Nov 2016 02:33:25 -0800 (PST) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uA9ASqr9002975 for ; Wed, 9 Nov 2016 05:33:24 -0500 Received: from e28smtp08.in.ibm.com (e28smtp08.in.ibm.com [125.16.236.8]) by mx0a-001b2d01.pphosted.com with ESMTP id 26kybx0rbb-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 09 Nov 2016 05:33:24 -0500 Received: from localhost by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 9 Nov 2016 16:03:21 +0530 Received: from d28relay06.in.ibm.com (d28relay06.in.ibm.com [9.184.220.150]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 8D15EE0045 for ; Wed, 9 Nov 2016 16:03:24 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay06.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id uA9AXJwf7405756 for ; Wed, 9 Nov 2016 16:03:19 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id uA9AXGTM000399 for ; Wed, 9 Nov 2016 16:03:19 +0530 Subject: Re: [PATCH v2 00/12] mm: page migration enhancement for thp References: <1478561517-4317-1-git-send-email-n-horiguchi@ah.jp.nec.com> From: Anshuman Khandual Date: Wed, 9 Nov 2016 16:03:04 +0530 MIME-Version: 1.0 In-Reply-To: <1478561517-4317-1-git-send-email-n-horiguchi@ah.jp.nec.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: <5822FB60.5040905@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi , linux-mm@kvack.org Cc: "Kirill A. Shutemov" , Hugh Dickins , Andrew Morton , Dave Hansen , Andrea Arcangeli , Mel Gorman , Michal Hocko , Vlastimil Babka , Pavel Emelyanov , Zi Yan , Balbir Singh , linux-kernel@vger.kernel.org, Naoya Horiguchi On 11/08/2016 05:01 AM, Naoya Horiguchi wrote: > Hi everyone, > > I've updated thp migration patches for v4.9-rc2-mmotm-2016-10-27-18-27 > with feedbacks for ver.1. > > General description (no change since ver.1) > =========================================== > > This patchset enhances page migration functionality to handle thp migration > for various page migration's callers: > - mbind(2) > - move_pages(2) > - migrate_pages(2) > - cgroup/cpuset migration > - memory hotremove > - soft offline > > The main benefit is that we can avoid unnecessary thp splits, which helps us > avoid performance decrease when your applications handles NUMA optimization on > their own. > > The implementation is similar to that of normal page migration, the key point > is that we modify a pmd to a pmd migration entry in swap-entry like format. Will it be better to have new THP_MIGRATE_SUCCESS and THP_MIGRATE_FAIL VM events to capture how many times the migration worked without first splitting the huge page and how many time it did not work ? Also do you have a test case which demonstrates this THP migration and kind of shows its better than the present split and move method ? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org