From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932362Ab2DJBWt (ORCPT ); Mon, 9 Apr 2012 21:22:49 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:60315 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752521Ab2DJBWs (ORCPT ); Mon, 9 Apr 2012 21:22:48 -0400 X-AuditID: 9c930179-b7b2cae000000ca1-02-4f838b65329d Message-ID: <4F838BF4.7020104@kernel.org> Date: Tue, 10 Apr 2012 10:25:08 +0900 From: Minchan Kim User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko/20120327 Thunderbird/11.0.1 MIME-Version: 1.0 Newsgroups: gmane.linux.kernel.mm,gmane.linux.kernel To: Rik van Riel , hannes@cmpxchg.org CC: Alexey Ivanov , "gnehzuil.lzheng@gmail.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , yinghan@google.com Subject: Re: mapped pagecache pages vs unmapped pages References: <37371333672160@webcorp7.yandex-team.ru> <4F7E9854.1020904@gmail.com> <12701333991475@webcorp7.yandex-team.ru> <4F8326FD.8020507@redhat.com> <8041334015453@webcorp4.yandex-team.ru> <4F837F6E.3010508@kernel.org> <4F838390.1080909@redhat.com> In-Reply-To: <4F838390.1080909@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2012-04-10 오전 9:49, Rik van Riel 쓴 글: > On 04/09/2012 08:31 PM, Minchan Kim wrote: >> 2012-04-10 오전 8:50, Alexey Ivanov 쓴 글: >> >>> Did you consider making this ratio tunable, at least manually(i.e. >>> via sysctl)? >>> I suppose we are not the only ones with almost-whole-ram-mmaped >>> workload. >> >> Personally, I think it's not good approach. >> It depends on kernel's internal implemenatation which would be changed >> in future as we chagend it at 2.6.28. > > I also believe that a tunable for this is not going to be > a very workable approach, for the simple reason that changing > the value does not make a predictable change in the effectiveness > of working set detection or protection. > >> In my opinion, kernel just should do best effort to keep active working >> set except some critical pages which are code pages. > > Johannes has some experimental code to measure refaults, and > calculate their distance in a multi-zone, multi-cgroup environment. > > That would allow us to predictably place things in the working set > as required. > Hannes, it can help many people if you post your code. ;) -- Kind regards, Minchan Kim