From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754134AbZELUTT (ORCPT ); Tue, 12 May 2009 16:19:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752208AbZELUTF (ORCPT ); Tue, 12 May 2009 16:19:05 -0400 Received: from mx2.redhat.com ([66.187.237.31]:36139 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751778AbZELUTE (ORCPT ); Tue, 12 May 2009 16:19:04 -0400 Message-ID: <4A09D957.2070908@redhat.com> Date: Tue, 12 May 2009 16:17:27 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: Christoph Lameter CC: KOSAKI Motohiro , Wu Fengguang , Andrew Morton , "hannes@cmpxchg.org" , "peterz@infradead.org" , "linux-kernel@vger.kernel.org" , "tytso@mit.edu" , "linux-mm@kvack.org" , "elladan@eskimo.com" , "npiggin@suse.de" , "minchan.kim@gmail.com" Subject: Re: [PATCH -mm] vmscan: protect a fraction of file backed mapped pages from reclaim References: <20090508125859.210a2a25.akpm@linux-foundation.org> <20090512025246.GC7518@localhost> <20090512120002.D616.A69D9226@jp.fujitsu.com> <4A09AC91.4060506@redhat.com> <4A09B46D.9010705@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Lameter wrote: > On Tue, 12 May 2009, Rik van Riel wrote: > >>> Streaming I/O means access once? >> Yeah, "used-once pages" would be a better criteria, since >> you could go through a gigantic set of used-once pages without >> doing linear IO. > > Can we see some load for which this patch has a beneficial effect? > With some numbers? How many do you want before you're satisfied that this benefits a significant number of workloads? How many numbers do you want to feel safe that no workloads suffer badly from this patch? Also, wow would you measure a concept as nebulous as desktop interactivity? Btw, the patch has gone into the Fedora kernel RPM to get a good amount of user testing. I'll let you know what the users say (if anything). -- All rights reversed.