Re: [PATCH v15 04/13] task_isolation: add initial support

[Chris Metcalf]

On 9/1/2016 6:06 AM, Peter Zijlstra wrote:
> On Tue, Aug 30, 2016 at 11:32:16AM -0400, Chris Metcalf wrote:
> > On 8/30/2016 3:58 AM, Peter Zijlstra wrote:
> > > What !? I really don't get this, what are you waiting for? Why is
> > > rescheduling making things better.
> > We need to wait for the last dyntick to fire before we can return to
> > userspace.  There are plenty of options as to what we can do in the
> > meanwhile.
> Why not keep your _TIF_TASK_ISOLATION_FOO flag set and re-enter the
> loop?
>
> I really don't see how setting TIF_NEED_RESCHED is helping anything.

Yes, I think I addressed that in an earlier reply to Frederic; and you're right,
I don't think TIF_NEED_RESCHED or schedule() are the way to go.

https://lkml.kernel.org/g/107bd666-dbcf-7fa5-ff9c-f79358899712@xxxxxxxxxxxx

Any thoughts on the question of "just re-enter the loop" vs. schedule_timeout()?

--
Chris Metcalf, Mellanox Technologies
http://www.mellanox.com