Re: [PATCH v5 4/9] x86: Enable Intel Turbo Boost Max Technology 3.0

From: Tim Chen
Date: Wed Oct 05 2016 - 12:05:27 EST


On Wed, 2016-10-05 at 16:23 +0200, Thomas Gleixner wrote:
> On Sat, 1 Oct 2016, Srinivas Pandruvada wrote:
> >
> > +void sched_set_itmt_support(bool itmt_supported)
> > +{
> > + mutex_lock(&itmt_update_mutex);
> > +
> > + if (itmt_supported != sched_itmt_capable)
> > + sched_itmt_capable = itmt_supported;
> Yikes. What is this conditional for? The only value it has is to confuse
> the reader.

Will remove the check.

>
> >
> > +
> > + mutex_unlock(&itmt_update_mutex);
> > +}
> > +
> > +DEFINE_PER_CPU_READ_MOSTLY(int, sched_core_priority);
> Darn. Do not stick variable definitiions in the middle of the code and
> especially not glued to the function w/o a newline in between. Move it to
> the top of the file.

Will move to top of file.

>
> >
> > +int arch_asym_cpu_priority(int cpu)
> > +{
> > + return per_cpu(sched_core_priority, cpu);
> > +}
>
> >
> > +void sched_set_itmt_core_prio(int prio, int core_cpu)
> > +{
> > + int cpu, i = 1;
> > +
> > + for_each_cpu(cpu, topology_sibling_cpumask(core_cpu)) {
> > + int smt_prio;
> > +
> > + /*
> > + Â* Ensure that the siblings are moved to the end
> > + Â* of the priority chain and only used when
> > + Â* all other high priority cpus are out of capacity.
> > + Â*/
> > + smt_prio = prio * smp_num_siblings / i;
> > + i++;
> Your code ordering is really random. What has this i++ to do with the
> store? Nothing. It just makes reading the code harder. Just move it below
> the store.

Will move it to the end of for loop.

>
> >
> > + per_cpu(sched_core_priority, cpu) = smt_prio;

Thanks.

Tim