From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265342AbUEZHzW (ORCPT ); Wed, 26 May 2004 03:55:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265346AbUEZHzV (ORCPT ); Wed, 26 May 2004 03:55:21 -0400 Received: from holomorphy.com ([207.189.100.168]:31125 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S265342AbUEZHzS (ORCPT ); Wed, 26 May 2004 03:55:18 -0400 Date: Wed, 26 May 2004 00:55:06 -0700 From: William Lee Irwin III To: Buddy Lumpkin Cc: orders@nodivisions.com, linux-kernel@vger.kernel.org Subject: Re: why swap at all? Message-ID: <20040526075506.GV1833@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Buddy Lumpkin , orders@nodivisions.com, linux-kernel@vger.kernel.org References: <40B43B5F.8070208@nodivisions.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 26, 2004 at 12:31:16AM -0700, Buddy Lumpkin wrote: > This is a really good point. I think the bar should be set at max > performance for systems that never need to use the swap device. > If someone wants to tune swap performance to their hearts content, so be it. > But given cheap prices for memory, and the horrible best case performance > for swap, an increase in swap performance should never, ever come at the > expense of performance for a system that has been sized such that executable > address spaces, libraries and anonymous memory will fit easily within > physical ram. > This of course doesn't address the VM paging storms that happen due to large > amounts of file system writes. Once the pagecache fills up, dirty pages must > be evicted from the pagecache so that new pages can be added to the > pagecache. If you've got a real performance issue, please describe it properly instead of asserting without evidence the existence of one. -- wli