From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933299AbXCFTsp (ORCPT ); Tue, 6 Mar 2007 14:48:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964852AbXCFTso (ORCPT ); Tue, 6 Mar 2007 14:48:44 -0500 Received: from one.firstfloor.org ([213.235.205.2]:37814 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933307AbXCFTsn (ORCPT ); Tue, 6 Mar 2007 14:48:43 -0500 Date: Tue, 6 Mar 2007 20:48:41 +0100 From: Andi Kleen To: Stephen Hemminger Cc: Roland Kuhn , Andi Kleen , Eric Dumazet , Jan Engelhardt , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [RFC] div64_64 support Message-ID: <20070306194841.GA5424@one.firstfloor.org> References: <20070223170527.4ca695b2@freekitty> <20070305155714.3abe1b5e@freekitty> <20070306133404.GA864@one.firstfloor.org> <200703061519.20346.dada1@cosmosbay.com> <20070306144529.GA2004@one.firstfloor.org> <84C47260-4B57-4568-8197-58F438A6F737@e18.physik.tu-muenchen.de> <20070306102941.32471d57@freekitty> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070306102941.32471d57@freekitty> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 06, 2007 at 10:29:41AM -0800, Stephen Hemminger wrote: > Don't count the existing Newton-Raphson out. It turns out that to get enough > precision for 32 bits, only 4 iterations are needed. By unrolling those, it > gets much better timing. But did you fix the >2^43 bug too? SGI has already shipped 10TB Altixen, so it's not entirely theoretical. -Andi