From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753583AbXDIQXF (ORCPT ); Mon, 9 Apr 2007 12:23:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753589AbXDIQXE (ORCPT ); Mon, 9 Apr 2007 12:23:04 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:53843 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753583AbXDIQXB (ORCPT ); Mon, 9 Apr 2007 12:23:01 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Roland McGrath Cc: Oleg Nesterov , Andrew Morton , Davide Libenzi , Ingo Molnar , Linus Torvalds , Robin Holt , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [RFC, PATCH 1/3] introduce SYS_CLONE_MASK References: <20070409020600.6338BD82F4@pipsqueak.sf.frob.com> Date: Mon, 09 Apr 2007 10:20:27 -0600 In-Reply-To: <20070409020600.6338BD82F4@pipsqueak.sf.frob.com> (Roland McGrath's message of "Sun, 8 Apr 2007 19:06:00 -0700 (PDT)") 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 Roland McGrath writes: > I concur with Eric's assessment. Adding new magic bits to the generic > clone path seems like a poor way to cope with kernel threads. I think > it's better if kernel thread setup gets less like normal user process > setup. I also agree with Eric that PPID of 0 is a very natural way for > kernel threads to be displayed. We need to know more about the nature > of the compatibility issue in procps to judge whether there is good > reason to avoid changing it. I just investigated the procps issue. Using init_task as the parent nothing sticks out as being wrong in /proc. Further when I modified pstree to accept 0 as it's starting pid (from which all else would be rooted). All of the kernel threads showed up. So if anything I it is a feature that kernel threads don't show up by default in pstree (when PPID == 0). It isn't a subtle kernel bug. Eric