Re: 2.6.16-rc6-rt1

From: Esben Nielsen
Date: Wed Mar 15 2006 - 06:19:49 EST


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
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/