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. From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45E8CFD8.7050808@redhat.com> Date: Fri, 02 Mar 2007 20:31:04 -0500 From: Rik van Riel MIME-Version: 1.0 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: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-kernel , linux-mm List-ID: 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. -- 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