Re: [PATCH] sched: Fix numabalancing to work with isolated cpus

From: Michal Hocko
Date: Thu Apr 06 2017 - 06:42:23 EST


On Thu 06-04-17 12:29:57, Peter Zijlstra wrote:
> On Thu, Apr 06, 2017 at 12:13:49PM +0200, Michal Hocko wrote:
> > On Thu 06-04-17 11:23:29, Peter Zijlstra wrote:
> > > On Thu, Apr 06, 2017 at 09:34:36AM +0200, Michal Hocko wrote:
> > [...]
> > > > I would really like to see it confirmed by the scheduler maintainers and
> > > > documented properly as well. What you are claiming here is rather
> > > > surprising to my understanding of what isolcpus acutally is.
> > >
> > > isolcpus gets you a set of fully partitioned CPUs. What's surprising
> > > about that?
> >
> > Well, I thought that all isolated cpus simply form their own scheduling
> > domain which is isolated from the general workload on the system
> > (kthreads, softirqs etc...).
>
> No, they all form their own 1 cpu partition.

Is this something dictated by usecases which rely on isolcpus or rather
nobody bothered to implement one scheduling domain?

--
Michal Hocko
SUSE Labs