Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763459AbXHGFTN (ORCPT ); Tue, 7 Aug 2007 01:19:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755294AbXHGFS7 (ORCPT ); Tue, 7 Aug 2007 01:18:59 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:55848 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751513AbXHGFS6 (ORCPT ); Tue, 7 Aug 2007 01:18:58 -0400 Date: Mon, 6 Aug 2007 22:18:24 -0700 From: Andrew Morton To: Oleg Nesterov Cc: "Eric W. Biederman" , Sukadev Bhattiprolu , Roland McGrath , linux-kernel@vger.kernel.org, containers@lists.osdl.org, Pavel Emelyanov Subject: Re: [RFC, PATCH] handle the multi-threaded init's exit() properly Message-Id: <20070806221824.22a78312.akpm@linux-foundation.org> In-Reply-To: <20070806203326.GA188@tv-sign.ru> References: <20070802212009.GA516@tv-sign.ru> <20070806131345.3322c99e.akpm@linux-foundation.org> <20070806203326.GA188@tv-sign.ru> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3576 Lines: 93 On Tue, 7 Aug 2007 00:33:26 +0400 Oleg Nesterov wrote: > On 08/06, Andrew Morton wrote: > > > > On Fri, 3 Aug 2007 01:20:09 +0400 Oleg Nesterov wrote: > > > > > 2. We are playing games with ->nsproxy->pid_ns. This code is bogus today, and > > > it has to be changed anyway when we really support pid namespaces, just > > > remove it. > > > > This patch broke > > > > pid-namespaces-define-and-use-task_active_pid_ns-wrapper.patch. This hunk: > > > > *************** > > *** 908,915 **** > > if (unlikely(!tsk->pid)) > > panic("Attempted to kill the idle task!"); > > if (unlikely(tsk == child_reaper(tsk))) { > > - if (tsk->nsproxy->pid_ns != &init_pid_ns) > > - tsk->nsproxy->pid_ns->child_reaper = init_pid_ns.child_reaper; > > else > > panic("Attempted to kill init!"); > > } > > --- 908,916 ---- > > if (unlikely(!tsk->pid)) > > panic("Attempted to kill the idle task!"); > > if (unlikely(tsk == child_reaper(tsk))) { > > + if (task_active_pid_ns(tsk) != &init_pid_ns) > > + task_active_pid_ns(tsk)->child_reaper = > > + init_pid_ns.child_reaper; > > else > > panic("Attempted to kill init!"); > > } > > > > has no place to live any more, so I just removed it. > > Ah, thanks. I should have done this patch against -mm tree. > > I hope it is OK to drop this chunk of > pid-namespaces-define-and-use-task_active_pid_ns-wrapper.patch > > Because it can't work right now anyway, and Sukadev+Pavel already have > new patches on top this one which make namespace switch actually work. > OK, well I had to make a bit of on-the-fly adjustment to pid-namespaces-rename-child_reaper-function.patch as well. The diff-of-the-diff is: @@ -48,7 +48,7 @@ diff -puN kernel/exit.c~pid-namespaces-rename-child_reaper-function kernel/exit.c --- a/kernel/exit.c~pid-namespaces-rename-child_reaper-function +++ a/kernel/exit.c -@@ -694,7 +694,7 @@ forget_original_parent(struct task_struc +@@ -683,7 +683,7 @@ forget_original_parent(struct task_struc do { reaper = next_thread(reaper); if (reaper == father) { @@ -57,19 +57,10 @@ break; } } while (reaper->exit_state); -@@ -907,7 +907,7 @@ fastcall NORET_TYPE void do_exit(long co - panic("Aiee, killing interrupt handler!"); - if (unlikely(!tsk->pid)) - panic("Attempted to kill the idle task!"); -- if (unlikely(tsk == child_reaper(tsk))) { -+ if (unlikely(tsk == task_child_reaper(tsk))) { - if (task_active_pid_ns(tsk) != &init_pid_ns) - task_active_pid_ns(tsk)->child_reaper = - init_pid_ns.child_reaper; diff -puN kernel/signal.c~pid-namespaces-rename-child_reaper-function kernel/signal.c Hopefully people can re-review and retest what's there in next -mm. Or if that's too much work or too risky, option b) is to drop handle-the-multi-threaded-inits-exit-properly.patch, go back to the 2.6.23-rc1-mm2 versions of pid-namespaces-define-and-use-task_active_pid_ns-wrapper.patch and pid-namespaces-rename-child_reaper-function.patch and to ask Oleg to cook a 2.6.23-rc1-mm2 version of handle-the-multi-threaded-inits-exit-properly.patch. The downside of this approach is that handle-the-multi-threaded-inits-exit-properly.patch looks more 2.6.24-ready than all the container stuff (based just on overall impact and speculativeness) - 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/