From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992876AbXCCBbX (ORCPT ); Fri, 2 Mar 2007 20:31:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992826AbXCCBbX (ORCPT ); Fri, 2 Mar 2007 20:31:23 -0500 Received: from mx1.redhat.com ([66.187.233.31]:37880 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992876AbXCCBbW (ORCPT ); Fri, 2 Mar 2007 20:31:22 -0500 Message-ID: <45E8CFD8.7050808@redhat.com> Date: Fri, 02 Mar 2007 20:31:04 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel , linux-mm Subject: Re: [PATCH] free swap space of (re)activated pages References: <45E88997.4050308@redhat.com> <20070302171818.d271348e.akpm@linux-foundation.org> In-Reply-To: <20070302171818.d271348e.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > On Fri, 02 Mar 2007 15:31:19 -0500 > Rik van Riel wrote: > >> the attached patch frees the swap space of already resident pages >> when swap space starts getting tight, instead of only freeing up >> the swap space taken up by newly swapped in pages. >> >> This should result in the swap space of pages that remain resident >> in memory being freed, allowing kswapd more chances to actually swap >> a page out (instead of rotating it back onto the active list). > > Fair enough. How do we work out if this helps things? I suspect it should mostly help on desktop systems that slowly fill up (and run out of) swap. I'm not sure how to create that synthetically. I have seen that swap is kept free much easier in a qsbench test, but that's probably not a very good test since it swaps things in and out all the time... -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic.