From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754606Ab0B1RuF (ORCPT ); Sun, 28 Feb 2010 12:50:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:5437 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754356Ab0B1RuB (ORCPT ); Sun, 28 Feb 2010 12:50:01 -0500 Message-ID: <4B8AAC9A.10203@redhat.com> Date: Sun, 28 Feb 2010 12:49:14 -0500 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.1 MIME-Version: 1.0 To: Johannes Weiner CC: Andrew Morton , KOSAKI Motohiro , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: mm: used-once mapped file page detection References: <1266868150-25984-1-git-send-email-hannes@cmpxchg.org> <20100224133946.a5092804.akpm@linux-foundation.org> <20100226143232.GA13001@cmpxchg.org> In-Reply-To: <20100226143232.GA13001@cmpxchg.org> 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 On 02/26/2010 09:32 AM, Johannes Weiner wrote: > On Wed, Feb 24, 2010 at 01:39:46PM -0800, Andrew Morton wrote: >> On Mon, 22 Feb 2010 20:49:07 +0100 Johannes Weiner wrote: >> >>> This patch makes the VM be more careful about activating mapped file >>> pages in the first place. The minimum granted lifetime without >>> another memory access becomes an inactive list cycle instead of the >>> full memory cycle, which is more natural given the mentioned loads. >> >> iirc from a long time ago, the insta-activation of mapped pages was >> done because people were getting peeved about having their interactive >> applications (X, browser, etc) getting paged out, and bumping the pages >> immediately was found to help with this subjective problem. >> >> So it was a latency issue more than a throughput issue. I wouldn't be >> surprised if we get some complaints from people for the same reasons as >> a result of this patch. > > Agreed. Although we now have other things in place to protect them once > they are active (VM_EXEC protection, lazy active list scanning). You think we'll need VM_EXEC protection on the inactive list after your changes?