Date: Wed, 15 Mar 2006 12:21:26 +0100 (MET)
From: Esben Nielsen <simlo@phys.au.dk>
To: Thomas Gleixner <tglx@linutronix.de>
cc: Ingo Molnar <mingo@elte.hu>, <linux-kernel@vger.kernel.org>
Subject: Re: 2.6.16-rc6-rt1
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On Tue, 14 Mar 2006, Thomas Gleixner wrote:

> On Tue, 2006-03-14 at 23:11 +0100, Ingo Molnar wrote:
> > > > no. We have to run deadlock detection to avoid things like circular lock
> > > > dependencies causing an infinite schedule+wakeup 'storm' during priority
> > > > boosting. (like possible with your wakeup based method i think)
> > > No, all tasks would just settle on the highest priority and then the
> > > wakeups would stop.
> >
> > you are right, that shouldnt be possible. But how about other, SMP
> > artifacts? What if the woken up task runs on another CPU, and the whole
> > chain of boosting is thus delayed?
>
> And it does not solve the problem of ad hoc deadlock detection at all.
>

I have a feeling that it can't be done without a global lock.
The idea I have with releasing the all locks in each iteration might not
give reliable results for deadlocking.

Esben

> 	tglx
>
>
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