Re: Filesystem lockup with CONFIG_PREEMPT_RT

From: Steven Rostedt
Date: Fri Jun 27 2014 - 13:54:22 EST


On Fri, 27 Jun 2014 19:34:53 +0200
Mike Galbraith <umgwanakikbuti@xxxxxxxxx> wrote:

> On Fri, 2014-06-27 at 10:01 -0400, Steven Rostedt wrote:
>
> > This seems like a lot of hacks.
>
> It is exactly that, lacking proper pooper-scooper, show rt kernel how to
> not step in it.
>
> > I'm wondering if it would work if we
> > just have the rt_spin_lock_slowlock not call schedule(), but call
> > __schedule() directly. I mean it would keep with the mainline paradigm
> > as spinlocks don't sleep there, and one going to sleep in the -rt
> > kernel is similar to it being preempted by a very long NMI.
>
> Problem being that we do sleep there, do need wakeup. I have a hack
> that turns them back into spinning locks, but it.. works too :)

Why do we need the wakeup? the owner of the lock should wake it up
shouldn't it?


-- Steve
--
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/