cpufreq and boost with amd ryzen

cpufreq and boost with amd ryzen

[Sergio P]

I was wondering why cpufreq is not creating
/sys/devices/system/cpu/cpufreq/boost for an AMD Ryzen processor? I am
running kernel 4.11.  I do see cpb (AMD's legacy core performance
boost) in each individual profile*/ but regardless, it does not seem
to boost.  (fyi no overclocking going on).

cpupower frequency-info reports
  boost state support:
    Supported: no
    Active: no

Re: cpufreq and boost with amd ryzen

[Viresh Kumar]

On Sun, Jul 2, 2017 at 8:04 PM, Sergio P <sergio.pieiga@gmail.com> wrote:
> I was wondering why cpufreq is not creating
> /sys/devices/system/cpu/cpufreq/boost for an AMD Ryzen processor? I am
> running kernel 4.11.  I do see cpb (AMD's legacy core performance
> boost) in each individual profile*/ but regardless, it does not seem
> to boost.  (fyi no overclocking going on).
>
> cpupower frequency-info reports
>   boost state support:
>     Supported: no
>     Active: no

Please give output of:

grep . /sys/devices/system/cpu/cpu0/cpufreq/*

I want to see what driver is running and what features are available.

--
viresh

Re: cpufreq and boost with amd ryzen

[Sergio P]

Hi Viresh, thank you for responding.

/sys/devices/system/cpu/cpu0/cpufreq/affected_cpus:0
/sys/devices/system/cpu/cpu0/cpufreq/bios_limit:3400000
/sys/devices/system/cpu/cpu0/cpufreq/cpb:0
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq:3400000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq:3400000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq:2200000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpu0/cpufreq/freqdomain_cpus:0 1
/sys/devices/system/cpu/cpu0/cpufreq/related_cpus:0
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies:3400000
3000000 2200000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors:userspace
powersave conservative ondemand performance schedutil
/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq:3400000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver:acpi-cpufreq
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor:ondemand
/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq:3400000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq:2200000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed:<unsupported>
grep: /sys/devices/system/cpu/cpu0/cpufreq/stats: Is a directory




On Mon, Jul 3, 2017 at 12:25 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On Sun, Jul 2, 2017 at 8:04 PM, Sergio P <sergio.pieiga@gmail.com> wrote:
>> I was wondering why cpufreq is not creating
>> /sys/devices/system/cpu/cpufreq/boost for an AMD Ryzen processor? I am
>> running kernel 4.11.  I do see cpb (AMD's legacy core performance
>> boost) in each individual profile*/ but regardless, it does not seem
>> to boost.  (fyi no overclocking going on).
>>
>> cpupower frequency-info reports
>>   boost state support:
>>     Supported: no
>>     Active: no
>
> Please give output of:
>
> grep . /sys/devices/system/cpu/cpu0/cpufreq/*
>
> I want to see what driver is running and what features are available.
>
> --
> viresh

Re: cpufreq and boost with amd ryzen

[Viresh Kumar]

On 03-07-17, 07:21, Sergio P wrote:
> Hi Viresh, thank you for responding.
> 
> /sys/devices/system/cpu/cpu0/cpufreq/affected_cpus:0
> /sys/devices/system/cpu/cpu0/cpufreq/bios_limit:3400000
> /sys/devices/system/cpu/cpu0/cpufreq/cpb:0
> /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq:3400000
> /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq:3400000
> /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq:2200000
> /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_transition_latency:0
> /sys/devices/system/cpu/cpu0/cpufreq/freqdomain_cpus:0 1
> /sys/devices/system/cpu/cpu0/cpufreq/related_cpus:0
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies:3400000
> 3000000 2200000
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors:userspace
> powersave conservative ondemand performance schedutil
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq:3400000
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver:acpi-cpufreq
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor:ondemand
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq:3400000
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq:2200000
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed:<unsupported>
> grep: /sys/devices/system/cpu/cpu0/cpufreq/stats: Is a directory

You need to help debugging a bit. Looks like you are returning early from
acpi_cpufreq_boost_init() (in drivers/cpufreq/acpi-cpufreq.c). Can you please
check if acpi_cpufreq_driver.set_boost is getting set ? Without that boost
wouldn't work.

-- 
viresh

Re: cpufreq and boost with amd ryzen

[Sergio P]

To be honest, I am not very familiar on how to debug the kernel.

My guess would be that X86_FEATURE_CPB is not being detected correctly
for Ryzen family in the CPUID registers, and it returns early from
acpi_cpufreq_boost_init().  Also, CPB was a feature in earlier AMD
processors, but now in the new Ryzen family, I'm not sure if it's
called something else and perhaps defined in a different CPUID bit.

Re: cpufreq and boost with amd ryzen

[Viresh Kumar]

+Rafael,

On 04-07-17, 16:38, Sergio P wrote:
> To be honest, I am not very familiar on how to debug the kernel.
> 
> My guess would be that X86_FEATURE_CPB is not being detected correctly
> for Ryzen family in the CPUID registers, and it returns early from
> acpi_cpufreq_boost_init().  Also, CPB was a feature in earlier AMD
> processors, but now in the new Ryzen family, I'm not sure if it's
> called something else and perhaps defined in a different CPUID bit.

@Rafael: Do you have any idea about the new Ryzen family or how to get boost
working on them ?

-- 
viresh

Re: cpufreq and boost with amd ryzen

[Rafael J. Wysocki]

On Wednesday, July 05, 2017 09:47:58 AM Viresh Kumar wrote:
> +Rafael,
> 
> On 04-07-17, 16:38, Sergio P wrote:
> > To be honest, I am not very familiar on how to debug the kernel.
> > 
> > My guess would be that X86_FEATURE_CPB is not being detected correctly
> > for Ryzen family in the CPUID registers, and it returns early from
> > acpi_cpufreq_boost_init().  Also, CPB was a feature in earlier AMD
> > processors, but now in the new Ryzen family, I'm not sure if it's
> > called something else and perhaps defined in a different CPUID bit.
> 
> @Rafael: Do you have any idea about the new Ryzen family or how to get boost
> working on them ?

Not from the top of my head, I need to look into the code.

In any case, IIRC, the boost and cpb attributes are mutually exclusive, so you
won't see the former if you see the latter.  I'm not sure how we decide which
one to expose, though.

Thanks,
Rafael