From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261331AbULHTi2 (ORCPT ); Wed, 8 Dec 2004 14:38:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261342AbULHTi2 (ORCPT ); Wed, 8 Dec 2004 14:38:28 -0500 Received: from holomorphy.com ([207.189.100.168]:7917 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S261331AbULHTf3 (ORCPT ); Wed, 8 Dec 2004 14:35:29 -0500 Date: Wed, 8 Dec 2004 11:35:24 -0800 From: William Lee Irwin III To: Bill Davidsen Cc: linux-kernel@vger.kernel.org Subject: Re: Limiting program swap Message-ID: <20041208193524.GU2714@holomorphy.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.6+20040722i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 08, 2004 at 02:07:36PM -0500, Bill Davidsen wrote: > I have several machine of various memory sizes which suffer from really > poor performance when doing backups. This appears to be because all the > programs other than the backup quickly get swapped to make room for i/o > buffers. > Is there some standard portable way to prevent this, either by reserving > some memory for programs which will not get swapped regardless of i/o > pressure, or alternatively limiting the total memory used for i/o > buffers, dcache, and similar things? > I did a crude hack for 2.4.17, but if I'm missing some obvious trick I'd > rather not do something which can't go in the mainline kernel. Anyone > care to show me what I missed, or is this just a characteristic of Linux? This appears at least superficially related to /proc/sys/vm/vfs_cache_pressure in 2.6.x-mm (possibly also mainline) -- wli