From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161252AbXCGDrz (ORCPT ); Tue, 6 Mar 2007 22:47:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161253AbXCGDrz (ORCPT ); Tue, 6 Mar 2007 22:47:55 -0500 Received: from smtp.osdl.org ([65.172.181.24]:46094 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161252AbXCGDrz (ORCPT ); Tue, 6 Mar 2007 22:47:55 -0500 Date: Tue, 6 Mar 2007 19:47:25 -0800 (PST) From: Linus Torvalds To: Eric Dumazet cc: "H. Peter Anvin" , Davide Libenzi , Linux Kernel Mailing List , Andrew Morton Subject: Re: [patch v2] epoll use a single inode ... In-Reply-To: <45EDCD11.8070000@cosmosbay.com> Message-ID: References: <200703061828.00253.dada1@cosmosbay.com> <200703061910.13431.dada1@cosmosbay.com> <45EDCD11.8070000@cosmosbay.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 6 Mar 2007, Eric Dumazet wrote: > > I did a user space program, attached to this mail. > > I rewrote the reciprocal_div() for i386 so that one multiply is used. Ok, this is definitely faster on Core 2 as well, so "numbers talk, bullshit walks". No more objections. (That said, I bet you could do even better for octal and hex numbers, so if you *really* want to speed things up, you should just make a special-case routine for each base (there's just three of them), and you can then also optimize the base-10 thing much better (you can do two digits at a time by dividing by 100, etc) Linus