From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933271AbXCFCeN (ORCPT ); Mon, 5 Mar 2007 21:34:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933279AbXCFCeN (ORCPT ); Mon, 5 Mar 2007 21:34:13 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:37953 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933271AbXCFCeM (ORCPT ); Mon, 5 Mar 2007 21:34:12 -0500 X-AuthUser: davidel@xmailserver.org Date: Mon, 5 Mar 2007 18:34:10 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: "H. Peter Anvin" cc: Linus Torvalds , Linux Kernel Mailing List , Andrew Morton , Eric Dumazet Subject: Re: [patch v2] epoll use a single inode ... In-Reply-To: <45ECD122.6020907@zytor.com> Message-ID: References: <45ECD122.6020907@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 Mon, 5 Mar 2007, H. Peter Anvin wrote: > Linus Torvalds wrote: > > > > Since this is not actually *used* for anything but showing the fd's in > > /proc//fd/ etc, no. In fact, an integer will wrap a *lot* less than a > > kernel data structure will be re-used, so even with the simple "wraps every > > 4G uses", you're still better off. > > > > ... and if that worries you, use a 64-bit counter. They're cheap (compared to > an sprintf), and even if they advance once a nanosecond they won't wrap around > for over 584 years. Right now is using: this.len = sprintf(name, "[%u.%d]", current->pid, fd); That should be unique and not have the wraparound problem. Ack? - Davide