From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965533AbXCFSKP (ORCPT ); Tue, 6 Mar 2007 13:10:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965538AbXCFSKP (ORCPT ); Tue, 6 Mar 2007 13:10:15 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:41899 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965520AbXCFSKM (ORCPT ); Tue, 6 Mar 2007 13:10:12 -0500 X-AuthUser: davidel@xmailserver.org Date: Tue, 6 Mar 2007 10:10:05 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: "H. Peter Anvin" cc: Eric Dumazet , Linus Torvalds , Linux Kernel Mailing List , Andrew Morton Subject: Re: [patch v2] epoll use a single inode ... In-Reply-To: <45ED96A6.3000704@zytor.com> Message-ID: References: <45ECD122.6020907@zytor.com> <45ECD3D4.5020305@zytor.com> <45ED08A9.9050501@cosmosbay.com> <45ED96A6.3000704@zytor.com> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc 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, H. Peter Anvin wrote: > Eric Dumazet wrote: > > > > For epoll, I suspect this is harmless : Programs dont allocate epolls fd > > every milli second, but at startup only. > > > > For pipes/sockets, using a 64 bits would be problematic, because sprintf() > > uses a divide for each digit. And a divide is slow. Ten divides are *very* > > slow. > > > > That's true for *any* sprintf(), though. sprintf() converts all its arguments > to 64 bits. Sigh! We *always* do do_div(), even for the more trivial %x case. Anyway, it does not really matter for the type of dfs will be applied to. - Davide