Re: [PATCH RFC] ioctl based CAT interface

Peter Zijlstra
2015-11-16T09:03:47Z

On Fri, Nov 13, 2015 at 02:04:38PM -0500, Luiz Capitulino wrote:
> I guess that what Peter is saying is that we don't want tasks
> attached to a reservation landing on a CPU where the reservation
> might be different or not existent at all.

Correct.

> This way, the ATTACH_RESERVATION command would fail if any
> of the CPUs in the cpumask are not part of the reservation.
> And then our code would have to be notified any time the process'
> affinity mask is changed (we either fail the affinity change
> or detach the process automatically from the reservation). Does
> this sound like a good solution?

No. We're not going to have random drivers muck about with affinity
masks, and most certainly not some manky ioctl.