Re: tasklet_unlock_wait() causes soft lockup with -rt and ieee1394audio

From: Daniel Walker
Date: Mon Jul 10 2006 - 10:39:58 EST


On Sun, 2006-07-09 at 13:17 +0200, Pieter Palmers wrote:
> >
> > I am just posting this for Pieter - all followups should be directed to
> > him. (I don't even have the hardware to reproduce this)
> >
> > IIRC the problem could only be reproduced with PREEMPT_RT. Pieter, can
> > you confirm?
>
> It can only be reproduced with PREEMPT_RT. And the test kernel is
> configured with irq threading, I haven't tried it without irq threading.

It's another one of those situations when a userspace real time process
gets stuck in a tight loop waiting for a bit to change. It's similar to
the issue with bit spinlocks, or yield.

You should be able to reproduce it without PREEMPT_RT but SMP only .

Daniel

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