Re: [PATCH RT 4/6] rt/locking: Reenable migration accross schedule

From: Mike Galbraith
Date: Mon Apr 18 2016 - 13:55:42 EST


On Mon, 2016-04-18 at 19:15 +0200, Sebastian Andrzej Siewior wrote:

> take 2. There is this else case in pin_current_cpu() where I take
> hp_lock. I didn't manage to get in there. So I *think* we can get rid of
> the lock now. Since there is no lock (or will be) we can drop the whole
> `do_mig_dis' checking and do the migrate_disable() _after_ we obtained
> the lock. We were not able to do so due to the lock hp_lock.
>
> And with this, I didn't manage to triger the lockup you had with
> futextest.

I'll have to feed it to DL980, hotplug and jitter test it. It seemed
to think that pinning post acquisition was a bad idea jitter wise, but
I was bending things up while juggling multiple boxen, so..

-Mike