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Date: Fri, 19 Aug 2011 17:24:16 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: "Serge E. Hallyn" <serge@hallyn.com>, akpm@linux-foundation.org,
        bonbons@linux-vserver.org, containers@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] Send a SIGCHLD to the init's pid namespace parent
	when reboot
Message-ID: <20110819152416.GA17034@redhat.com>
References: <1313094241-3674-1-git-send-email-daniel.lezcano@free.fr> <20110814161707.GB30846@redhat.com> <20110814213642.GB13799@hallyn.com> <20110815144744.GA9660@redhat.com> <4E4DA461.8030006@free.fr>
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On 08/19, Daniel Lezcano wrote:
>
> On 08/15/2011 04:47 PM, Oleg Nesterov wrote:
> >
> > 	- sys_reboot(cmd) does
> >
> > 		if (!global_namespace) {
> > 			task_active_pid_ns(current)->reboot_cmd = cmd;
> > 			sigkill_my_init();
> > 		}
>
> Hi Oleg,
>
> what would be your advice to get rid of from_ancestor_ns which prevent
> the signal to be delivered to the init process ?

Sure, a plain kill can't work. You can do force_sig_info(), this clears
SIGNAL_UNKILLABLE.

Hmm. But now I seem to recall we have other reasons to make the new
sigkill_task() helper... We will see. Anyway, force_ should work afaics.

Oleg.