From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] tcp_cubic: faster cube root Date: Tue, 06 Mar 2007 20:20:52 -0800 (PST) Message-ID: <20070306.202052.03980320.davem@davemloft.net> References: <20070306102941.32471d57@freekitty> <20070306.135834.26100913.davem@davemloft.net> <20070306144706.4585c079@freekitty> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: rkuhn@e18.physik.tu-muenchen.de, andi@firstfloor.org, dada1@cosmosbay.com, jengelh@linux01.gwdg.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: shemminger@linux-foundation.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:42743 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1161282AbXCGEUz (ORCPT ); Tue, 6 Mar 2007 23:20:55 -0500 In-Reply-To: <20070306144706.4585c079@freekitty> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Stephen Hemminger Date: Tue, 6 Mar 2007 14:47:06 -0800 > The Newton-Raphson method is quadratically convergent so > only a small fixed number of steps are necessary. > Therefore it is faster to unroll the loop. Since div64_64 is no longer > inline it won't cause code explosion. > > Also fixes a bug that can occur if x^2 was bigger than 32 bits. > > Signed-off-by: Stephen Hemminger Applied, thanks Stephen.