Re: combinatorial explosion in lockdep

From: David Miller
Date: Mon Jul 28 2008 - 18:57:01 EST


From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Mon, 28 Jul 2008 15:50:04 -0700

> David Miller wrote:
> > The triggering event seems to be kstopmachine as done by the first
> > module load. This seems to create the situation where we do double RQ
> > locking on essentially all the run queues, in order to move the
> > kstopmachine threads around to their proprer cpus. I think this is
> > what starts to make the lockdep dependency chains huge.
> >
>
> Does Rusty's stop_machine rewrite which puts the threads on the correct
> cpus to start with at least mitigate the symptoms?

I could check that, but it won't keep this from happening
and being triggerable by a trivial userland program setting
scheduler affinities.
--
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/