From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261914AbTLHUPY (ORCPT ); Mon, 8 Dec 2003 15:15:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261928AbTLHUPY (ORCPT ); Mon, 8 Dec 2003 15:15:24 -0500 Received: from head.linpro.no ([80.232.36.1]:21217 "EHLO head.linpro.no") by vger.kernel.org with ESMTP id S261914AbTLHUPV (ORCPT ); Mon, 8 Dec 2003 15:15:21 -0500 To: William Lee Irwin III Cc: linux-kernel@vger.kernel.org Subject: Re: 2.4: mylex and > 2GB RAM References: <1070897058.25490.56.camel@netstat.linpro.no> <20031208153641.GJ8039@holomorphy.com> <1070898870.25490.76.camel@netstat.linpro.no> <20031208162214.GW19856@holomorphy.com> From: Per Andreas Buer Organization: Linpro AS Date: Mon, 08 Dec 2003 21:15:15 +0100 In-Reply-To: <20031208162214.GW19856@holomorphy.com> (William Lee Irwin, III's message of "Mon, 8 Dec 2003 08:22:14 -0800") Message-ID: User-Agent: Gnus/5.1002 (Gnus v5.10.2) Emacs/21.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Spam-Score: -4.9 (----) X-Scanner: exiscan for exim4 (http://duncanthrax.net/exiscan/) *1ATRml-0007Zx-Iv*zo9TD80oaEA* Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org William Lee Irwin III writes: > If your memory ended at 2GB and the driver had 31-bit DMA, it may have > decided to use unconstrained allocations. Then, when you added more RAM, > it was forced to ask for <= 896MB, which made it copy to buffers that are > actually below 896MB most of the time. But this would reduce the throuput only a few percent, right? My system slows down from writing ~ 100MB/s to maybe 50KB/s. -- Per Andreas Buer