Re: [PATCH v1 2/2] cpufreq: ACPI: Update arch scale-invariance max perf ratio if CPPC is not there

From: Rafael J. Wysocki
Date: Fri Feb 05 2021 - 07:29:00 EST


On Fri, Feb 5, 2021 at 12:59 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Thu, Feb 04, 2021 at 06:34:32PM +0100, Rafael J. Wysocki wrote:
>
> > arch/x86/kernel/smpboot.c | 1 +
> > drivers/cpufreq/acpi-cpufreq.c | 8 ++++++++
> > 2 files changed, 9 insertions(+)
> >
> > Index: linux-pm/drivers/cpufreq/acpi-cpufreq.c
> > ===================================================================
> > --- linux-pm.orig/drivers/cpufreq/acpi-cpufreq.c
> > +++ linux-pm/drivers/cpufreq/acpi-cpufreq.c
> > @@ -806,6 +806,14 @@ static int acpi_cpufreq_cpu_init(struct
> > state_count++;
> > valid_states++;
> > data->first_perf_state = valid_states;
> > + } else {
> > + /*
> > + * If the maximum "boost" frequency is unknown, ask the arch
> > + * scale-invariance code to use the "nominal" performance for
> > + * CPU utilization scaling so as to prevent the schedutil
> > + * governor from selecting inadequate CPU frequencies.
> > + */
> > + arch_set_max_freq_ratio(true);
> > }
> >
> > freq_table = kcalloc(state_count, sizeof(*freq_table), GFP_KERNEL);
> > Index: linux-pm/arch/x86/kernel/smpboot.c
> > ===================================================================
> > --- linux-pm.orig/arch/x86/kernel/smpboot.c
> > +++ linux-pm/arch/x86/kernel/smpboot.c
> > @@ -1833,6 +1833,7 @@ void arch_set_max_freq_ratio(bool turbo_
> > arch_max_freq_ratio = turbo_disabled ? SCHED_CAPACITY_SCALE :
> > arch_turbo_freq_ratio;
> > }
> > +EXPORT_SYMBOL_GPL(arch_set_max_freq_ratio);
>
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

Thanks, I'm queuing up this lot for a post-rc7 late push.