Regression, bisected: hyperv shutdown panics guest

Regression, bisected: hyperv shutdown panics guest

[Florian Westphal]

With 3.7, hyperv guest shutdown no longer works.
Instead, guest kernel throws a bunch of "BUG: scheduling-while-atomic"
errors and then dies.

reverting

commit 6c0c0d4d1080840eabb3d055d2fd81911111c5fd
Author: hongfeng <hongfeng@marvell.com>
Date:   Thu Oct 4 17:12:25 2012 -0700
poweroff: fix bug in orderly_poweroff()

fixes this problem.

Greping for users of orderly_poweroff() shows that hyperv isn't
the only caller that invokes the function from irq context.

In fact, kdoc for orderly_poweroff says:

* This may be called from any context to trigger a system shutdown.
* If the orderly shutdown fails, it will force an immediate shutdown.

Any suggestions on how to properly fix this?

Thanks,
Florian

RE: Regression, bisected: hyperv shutdown panics guest

[KY Srinivasan]

> -----Original Message-----
> From: Florian Westphal [mailto:fw@strlen.de]
> Sent: Thursday, February 07, 2013 5:54 AM
> To: Feng Hong
> Cc: ebiederm@xmission.com; Kees Cook; linux-kernel@vger.kernel.org; KY
> Srinivasan; Haiyang Zhang
> Subject: Regression, bisected: hyperv shutdown panics guest
> 
> With 3.7, hyperv guest shutdown no longer works.
> Instead, guest kernel throws a bunch of "BUG: scheduling-while-atomic"
> errors and then dies.
> 
> reverting
> 
> commit 6c0c0d4d1080840eabb3d055d2fd81911111c5fd
> Author: hongfeng <hongfeng@marvell.com>
> Date:   Thu Oct 4 17:12:25 2012 -0700
> poweroff: fix bug in orderly_poweroff()
> 
> fixes this problem.
> 
> Greping for users of orderly_poweroff() shows that hyperv isn't
> the only caller that invokes the function from irq context.
> 
> In fact, kdoc for orderly_poweroff says:
> 
> * This may be called from any context to trigger a system shutdown.
> * If the orderly shutdown fails, it will force an immediate shutdown.
> 
> Any suggestions on how to properly fix this?
> 
> Thanks,
> Florian
> 

A patch has been submitted to fix this problem. It is in Greg's queue:
Subject: Re: [PATCH 6/6] Drivers: hv: Execute shutdown in a thread context


Regards,

K. Y