From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754324Ab2DFQXJ (ORCPT ); Fri, 6 Apr 2012 12:23:09 -0400 Received: from terminus.zytor.com ([198.137.202.10]:44194 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753936Ab2DFQXH (ORCPT ); Fri, 6 Apr 2012 12:23:07 -0400 Message-ID: <4F7F1864.8090606@zytor.com> Date: Fri, 06 Apr 2012 09:23:00 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120209 Thunderbird/10.0.1 MIME-Version: 1.0 To: Alexey Dobriyan CC: akpm@linux-foundation.org, viro@zeniv.linux.org.uk, torvalds@linux-foundation.org, drepper@gmail.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] nextfd(2) References: <20120401125741.GA7484@p183.telecom.by> <4F78D0BA.9040709@zytor.com> In-Reply-To: X-Enigmail-Version: 1.3.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/06/2012 02:54 AM, Alexey Dobriyan wrote: > > Without proc knowledge about fdtable is gathered linearly and still unreliable. > With nextfd(2), even procful environments could lose several failure branches. > And they can keep old dumb fd++ or smart /proc/self/fd loops for a change. > Incidentally, if we were to create a system call for this -- which I so far see no reason for -- I would make it return a select-style bitmask of file descriptors in use, not a "next fd" which would require a system call per iteration. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.