Re: [GIT PULL] isolation: 1Hz residual tick offloading v3

From: Frederic Weisbecker
Date: Tue Jan 16 2018 - 17:53:54 EST


On Tue, Jan 16, 2018 at 06:58:18PM +0100, Mike Galbraith wrote:
> On Tue, 2018-01-16 at 16:41 +0100, Frederic Weisbecker wrote:
> > On Fri, Jan 12, 2018 at 02:18:13PM -0500, Luiz Capitulino wrote:
> >
> > > Why are extending isolcpus= given that it's a deprecated interface?
> > > Some people have already moved away from isolcpus= now, but with this
> > > new feature they will be forced back to using it.
> >
> > I tried to remove isolcpus or at least change the way it works so that its
> > effects are reversible (ie: affine the init task instead of isolating domains)
> > but that got nacked due to the behaviour's expectations for userspace.
>
> So we paint ourselves into a static corner forever more, despite every
> bit of this being all about "properties of sets of cpus", ie precisely
> what cpusets was born to do.  That's sad, dynamic wasn't that far away.

Hence why we need to propagate "isolcpus=" to cpusets.