From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760558AbXK1LeS (ORCPT ); Wed, 28 Nov 2007 06:34:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758696AbXK1LeE (ORCPT ); Wed, 28 Nov 2007 06:34:04 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:35999 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757550AbXK1LeC (ORCPT ); Wed, 28 Nov 2007 06:34:02 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Ingo Molnar Cc: Albert Cahalan , Guillaume Chazarain , akpm@linux-foundation.org, mm-commits@vger.kernel.org, oleg@tv-sign.ru, rjw@sisk.pl, roland@redhat.com, xemul@openvz.org, linux-kernel , Ulrich Drepper Subject: Re: + proc-fix-the-threaded-proc-self.patch added to -mm tree References: <200711262339.lAQNdNrw029057@imap1.linux-foundation.org> <20071128014901.4b303954@inria.fr> <787b0d920711280141v463759efod86395c50c1b47c5@mail.gmail.com> <20071128104622.GB19694@elte.hu> Date: Wed, 28 Nov 2007 04:31:53 -0700 In-Reply-To: <20071128104622.GB19694@elte.hu> (Ingo Molnar's message of "Wed, 28 Nov 2007 11:46:22 +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 Ingo Molnar writes: > * Albert Cahalan wrote: > >> On Nov 27, 2007 7:49 PM, Guillaume Chazarain wrote: >> > akpm@linux-foundation.org wrote: >> > >> > > We may be stuck with the current broken behavior for backwards >> > > compatibility reasons but lets try fixing our ancient bug for the 2.6.25 >> > > time frame and see if anyone screams. >> >> It's not broken. It's just not the feature you're looking for. > > well it's quite broken at the moment and we are looking for solutions > not for a blame game :-) You might have read the thread where i describe > what i had to go through to do something fairly trivial. Yes. In a lot of ways if you access /proc/self and you get back information that does not correspond to yourself the result is nonsense. Which is a fairly mighty problem. I'm still trying to understand which will break user space more, adding /proc/task or changing /proc/self. >> This one is probably best: >> /proc/task -> 123/task/456 >> (with both numbers showing) > > this sounds good to me. If it's a symlink then there's not much other > choice because the thread PIDs do not even show up under /proc anymore. The name sounds good to me. I am not certain the two components make sense as we have a possible permission problem where it is remotely possible that a task will have permission to access /proc/ but not /proc/. We certainly need to think through that case before making it to a stable kernel. The reason I care is that we need to fix /proc/mounts. So once we have /proc/task we can also have change /proc/mounts to be a symlink to /proc/task/mounts. Once we get the /proc/mounts thing sorted out. There are several other entries in /proc that need to that need to follow in it's wake as they also become per namespace. /proc/net and /proc/sysvipc for starters. Eric