linux-kernel - Re: [PATCH 2/4] xen/manage: Poweroff forcefully if user-space is not yet up.

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Date:	Tue, 26 Nov 2013 11:47:03 -0500
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	David Vrabel <david.vrabel@...rix.com>
Cc:	Ian.Campbell@...rix.com, xen-devel@...ts.xenproject.org,
	linux-kernel@...r.kernel.org, JBeulich@...e.com,
	boris.ostrovsky@...cle.com
Subject: Re: [PATCH 2/4] xen/manage: Poweroff forcefully if user-space is not
 yet up.

On Thu, Nov 21, 2013 at 11:33:49AM +0000, David Vrabel wrote:
> On 08/11/13 17:38, Konrad Rzeszutek Wilk wrote:
> > The user can launch the guest in this sequence:
> > 
> > xl create -p /vm.cfg	[launch, but pause it]
> > xl shutdown latest	[sets control/shutdown=poweroff]
> > xl unpause latest
> > xl console latest	[and see that the guest has completely
> > ignored the shutdown request]
> > 
> > In reality the guest hasn't ignored it. It registers a watch
> > and gets a notification that there is value. It then calls
> > the shutdown_handler which ends up calling orderly_shutdown.
> 
> Is this really a bug?.

Yes. We did get the action, we just did not properly act on it.
> 
> >From the xl(1) man page.
> 
>   shutdown [OPTIONS] -a|domain-id
>      Gracefully shuts down a domain.  This coordinates with the
>      domain OS to perform graceful shutdown, so there is no guarantee
>      that it will succeed, and may take a variable length of time
>      depending on what services must be shutdown in the domain.
> 
> Seems like ignoring a shutdown request when the guest cannot yet
> shutdown gracefully is the expected behaviour.
> 
> This also doesn't seem sufficient.  SYSTEM_RUNNING is set prior to
> starting init in an initramfs and orderly_power_off(false) will still
> likely fail at this point.

Ugh, will have to figure out how else to realize when it the user-space
is ready to launch programs.
> 
> David
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