Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759907AbXKTWSO (ORCPT ); Tue, 20 Nov 2007 17:18:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760229AbXKTWR4 (ORCPT ); Tue, 20 Nov 2007 17:17:56 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:37221 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759574AbXKTWRz (ORCPT ); Tue, 20 Nov 2007 17:17:55 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Ingo Molnar Cc: Pavel Emelyanov , "Rafael J. Wysocki" , Pavel Machek , kernel list , netdev Subject: Re: 2.6.24-rc3: find complains about /proc/net References: <20071119191000.GA1560@elf.ucw.cz> <200711192304.25087.rjw@sisk.pl> <4743026B.2020907@openvz.org> <20071120215914.GE24156@elte.hu> Date: Tue, 20 Nov 2007 15:17:00 -0700 In-Reply-To: <20071120215914.GE24156@elte.hu> (Ingo Molnar's message of "Tue, 20 Nov 2007 22:59:14 +0100") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) 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 Content-Length: 1930 Lines: 46 Ingo Molnar writes: > * Eric W. Biederman wrote: > >> > lr-x------ 1 root root 64 Nov 20 18:03 3 -> /proc/net >> > ... >> >> Yes all of those are nasty. So much for my clever way of implementing >> these things. Grr. Simple hacks that almost work! > > btw., in case you feel inclined, i recently did some userspace coding > and found to my surprise that /proc/self points to the parent task, not > the thread itself (giving threads no real way to examine themselves). If > you are hacking in this area, would it be a big trouble to add something > like /proc/self-task/ or something like that? I had to use a raw gettid > syscall to figure out the TID to get to /proc/*/tasks/TID/sched > instrumentation info - which is quite a PITA. Agreed. I have been debating with myself in the last couple of days if it is a bug that /proc/self uses the tgid and not the actual pid/tid value. If I can be convinced that posix threads don't care I will happily just switch /proc/self, calling the current implementation a bug. I think it is a bug the real question is what are the backwards compatibility implications. Do posix threads care? It appears to me that either we need to fix /proc/self or we need to add /proc/task-self and fix /proc/mounts to point at that. In the normal case we share all of the same things so I think it is a don't care. Except that /proc/self/status | grep Pid returns the tgid. Hmm. I think I am just going to send Andrew a patch for 2.6.25 that just fixes /proc/self. I just fail to see how using the tgid is correct. The only cases we could care seem to do the wrong thing when we use the tgid. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/