On Mon, Mar 28, 2016 at 11:29:52AM +0200, Borislav Petkov wrote:
> On Mon, Mar 28, 2016 at 01:32:12PM +0800, Huang Rui wrote:
> > +
> > + get_online_cpus();
> > + this_cpu = get_cpu();
>
> What now?
>
> get_online_cpus() is enough.
>
Will remove get_cpu().
> > +
> > + /*
> > + * Choose the first online core of each compute unit, and then
> > + * read their MSR value of power and ptsc in a single IPI,
> > + * because the MSR value of CPU core represent the compute
> > + * unit's.
> > + */
> > + for_each_online_cpu(cpu) {
> > + target = cpumask_first(topology_sibling_cpumask(cpu));
> > + if (!cpumask_test_cpu(target, mask))
> > + cpumask_set_cpu(target, mask);
> > + }
>
> I think you want something like this: iterate over each core and put one
> of them into the mask.
>
> core = -1;
>
> for_each_online_cpu(cpu) {
> this_core = topology_core_id(cpu);
>
> if (this_core == core)
> continue;
>
> core = this_core;
>
> /* get any CPU on this compute unit */
> cpumask_set_cpu(cpumask_any(topology_sibling_cpumask(cpu)),
> mask);
> }
>
Yep, with new x86 topology for core on AMD, using this way should be
more clear.
Thanks,
Rui
