Re: [PATCH v4] time/tick-sched: idle load balancing when nohz_full cpu becomes idle.

[Peter Zijlstra]

On Thu, May 16, 2024 at 05:32:56PM +0200, Frederic Weisbecker wrote:
> On Thu, May 16, 2024 at 05:19:53PM +0200, Peter Zijlstra wrote:

> > Yes, but stronger, as long as the CPU is part of a load-balance domain,
> > it must not disable the tick while running anything.
> > 
> > that is, NOHZ_FULL must not become active unless it's running on a
> > single CPU partition.
> 
> I like the idea but I'm afraid to introduce regressions while doing so,
> with people currently using nohz_full without proper partionning...

There is no regression, if this is possible today it is utterly broken.

This should never have been possible.