Re: Preempt-rt on 3.2.23 raspberry pi kernel

Thomas Gleixner
2012-10-28T10:44:17Z

On Mon, 30 Jul 2012, Nick Lott wrote:

> I have a complete kernel log of the same problem but on 3.16 with rt27.
>
> http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=9311
>
> I've not had time to go any further with this or update and test
> with a newer kerenel.

Unfortunately verbose debug info is off, but it looks like you are
running into a recursive locking problem. You don't see it when you
switch back to !RT because the spinlocks become noops as this is an UP
machine.

Of course this proves, that nobody ever cared to boot a kernel with
DEBUG_SPINLOCK or even LOCKDEP enabled. That would have exposed such
problems. Hint: Documentation/SubmitChecklist and
Documentation/development-process/4.Coding exist for very good
reasons.

Thanks,

tglx