RE: [PATCH v11 01/13] x86/resctrl: Replace smp_call_function_many() with on_each_cpu_mask()

[Luck, Tony]

> > > + /* Update resource control msr on all the CPUs. */
> > > + on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1);
> >
> > Do you require these updates to done immediately via an IPI? or can they be
> > done bit lazy via schedule_on_each_cpu()?
>
> I have not experimented with lazy schedule.  At least I know the call
> update_cpu_closid_rmid should be completed immediately. Otherwise, the
> result might be inconsistent as the tasks(or CPUs)  could be running on
> two different closed/rmids before it is updated on all CPUs in the domain.

I think this does need to happen somewhat urgently. Imagine trying to give
some extra resources to a CPU bound real-time process. That process will
keep running with the old resource allocation.

-Tony