Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264939AbUFAIzM (ORCPT ); Tue, 1 Jun 2004 04:55:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264941AbUFAIzL (ORCPT ); Tue, 1 Jun 2004 04:55:11 -0400 Received: from holomorphy.com ([207.189.100.168]:58766 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S264939AbUFAIzI (ORCPT ); Tue, 1 Jun 2004 04:55:08 -0400 Date: Tue, 1 Jun 2004 01:54:56 -0700 From: William Lee Irwin III To: John Bradford Cc: Nick Piggin , Michael Brennan , linux-kernel@vger.kernel.org Subject: Re: why swap at all? Message-ID: <20040601085456.GJ2093@holomorphy.com> Mail-Followup-To: William Lee Irwin III , John Bradford , Nick Piggin , Michael Brennan , linux-kernel@vger.kernel.org References: <40BB88B5.8080300@ezrs.com> <200405312029.i4VKTCZ0000596@81-2-122-30.bradfords.org.uk> <40BBB5F7.1010407@yahoo.com.au> <200406010834.i518Y1cT000414@81-2-122-30.bradfords.org.uk> <20040601083206.GI2093@holomorphy.com> <200406010850.i518o8PD000134@81-2-122-30.bradfords.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200406010850.i518o8PD000134@81-2-122-30.bradfords.org.uk> User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 904 Lines: 21 Quote from William Lee Irwin III : >> So you can move userspace pages out of ZONE_DMA as-needed. On Tue, Jun 01, 2004 at 09:50:08AM +0100, John Bradford wrote: > But how does that improve performance before untouched RAM, (496788 in this > example), is exhausted? > In normal use, (almost always CPU bound), I've honestly never noticed any > performance gain from having swap configured. I must admit I haven't put > a lot of effort recently in to looking at this, but I have never been able > to reproduce these 'swap increases performance even with untouched RAM' > claims. Because ZONE_DMA, the lower 16MB is not all of RAM. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/