Re: [PATCH] sched/rt: RT_RUNTIME_GREED sched feature

[Christoph Lameter]

On Mon, 7 Nov 2016, Steven Rostedt wrote:

> On Mon, 7 Nov 2016 13:30:15 -0600 (CST)
> Christoph Lameter <cl@xxxxxxxxx> wrote:
>
> > SCHED_RR tasks alternately running on on cpu can cause endless deferral of
> > kworker threads. With the global effect of the OS processing reserved
> > it may be the case that the processor we are executing never gets any
> > time. And if that kworker threads role is releasing a mutex (like the
> > cgroup_lock) then deadlocks can result.
>
> I believe SCHED_RR tasks will still throttle if they use up too much of
> the CPU. But I still don't see how this patch helps your situation.

The kworker thread will be able to make progress? Or am I not reading this
correctly?