Re: [PATCH 19/33] sched/isolation: Remove HK_TYPE_TICK test from cpu_is_isolated()

[Frederic Weisbecker]

Le Tue, Sep 02, 2025 at 11:48:16AM -0400, Waiman Long a écrit :
> 
> On 9/2/25 10:28 AM, Waiman Long wrote:
> > 
> > On 8/29/25 11:48 AM, Frederic Weisbecker wrote:
> > > It doesn't make sense to use nohz_full without also isolating the
> > > related CPUs from the domain topology, either through the use of
> > > isolcpus= or cpuset isolated partitions.
> > > 
> > > And now HK_TYPE_DOMAIN includes all kinds of domain isolated CPUs.
> > > 
> > > This means that HK_TYPE_KERNEL_NOISE (of which HK_TYPE_TICK is only an
> > > alias) is always a superset of HK_TYPE_DOMAIN.
> > 
> > That may not be true. Users can still set "isolcpus=" and "nohz_full="
> > with disjoint set of CPUs whether cpuset is used for additional isolated
> > CPUs or not.
> 
> Instead of "is always a superset", I would prefer to use "should always be a
> superset" as it is a recommendation but users can still violate it.

Good point!

> Cheers,
> Longman
> 

-- 
Frederic Weisbecker
SUSE Labs