linux-kernel - Re: [PATCH 0/2] intel_pstate: fix turbo not being used after a processor is rebooted

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Message-ID: <72bcd14eef038ec9181d30b3d196b0a872f47ccb.camel@linux.intel.com>
Date:   Wed, 21 Dec 2022 13:34:18 -0800
From:   srinivas pandruvada <srinivas.pandruvada@...ux.intel.com>
To:     Pratyush Yadav <ptyadav@...zon.de>, linux-pm@...r.kernel.org
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        Len Brown <lenb@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Robert Moore <robert.moore@...el.com>,
        linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
        devel@...ica.org
Subject: Re: [PATCH 0/2] intel_pstate: fix turbo not being used after a
 processor is rebooted

On Wed, 2022-12-21 at 16:52 +0100, Pratyush Yadav wrote:
> When a processor is brought offline and online again, it is unable to
> use Turbo mode because the _PSS table does not contain the whole
> turbo
> frequency range, but only +1 MHz above the max non-turbo frequency.
> This
> causes problems when ACPI processor driver tries to set frequency
> constraints. See patch 2 for more details.
> 
Are you using some _PPC constraint to force to limit frequency?
I did a offline/online with PPC=0 with no HWP, I can get to full turbo
range.

[  121.237752] smpboot: CPU 1 is now offline
[  125.734886] x86: Booting SMP configuration:
[  125.734892] smpboot: Booting Node 0 Processor 1 APIC 0x2
[  125.741007] intel_pstate: CPU 1 going online
[  125.741692] intel_pstate: CPU1 - ACPI _PSS perf data
[  125.741698] intel_pstate:      *P0: 2301 MHz, 28000 mW, 0x2a00
[  125.741703] intel_pstate:       P1: 2300 MHz, 28000 mW, 0x1700
[  125.741705] intel_pstate:       P2: 2200 MHz, 26297 mW, 0x1600
[  125.741707] intel_pstate:       P3: 2000 MHz, 23263 mW, 0x1400
[  125.741710] intel_pstate:       P4: 1900 MHz, 21924 mW, 0x1300
[  125.741712] intel_pstate:       P5: 1800 MHz, 20612 mW, 0x1200
[  125.741714] intel_pstate:       P6: 1600 MHz, 17812 mW, 0x1000
[  125.741716] intel_pstate:       P7: 1500 MHz, 16581 mW, 0xf00
[  125.741718] intel_pstate:       P8: 1300 MHz, 13946 mW, 0xd00
[  125.741720] intel_pstate:       P9: 1200 MHz, 12796 mW, 0xc00
[  125.741722] intel_pstate:       P10: 1100 MHz, 11426 mW, 0xb00
[  125.741724] intel_pstate:       P11: 900 MHz, 9250 mW, 0x900
[  125.741726] intel_pstate:       P12: 800 MHz, 7965 mW, 0x800
[  125.741729] intel_pstate:       P13: 700 MHz, 6940 mW, 0x700
[  125.741731] intel_pstate:       P14: 500 MHz, 4738 mW, 0x500
[  125.741733] intel_pstate:       P15: 400 MHz, 3787 mW, 0x400
[  125.741735] intel_pstate: _PPC limits will be enforced
[  125.741740] intel_pstate: policy->max > max non turbo frequency
[  125.741742] intel_pstate: cpu:1 min_policy_perf:4 max_policy_perf:42
[  125.741745] intel_pstate: cpu:1 global_min:4 global_max:42
[  125.741747] intel_pstate: cpu:1 max_perf_ratio:42 min_perf_ratio:4
[  125.742243] intel_pstate: policy->max > max non turbo frequency
[  125.742247] intel_pstate: cpu:1 min_policy_perf:4 max_policy_perf:42
[  125.742251] intel_pstate: cpu:1 global_min:4 global_max:42
[  125.742255] intel_pstate: cpu:1 max_perf_ratio:42 min_perf_ratio:4


It is not clear how to get to this non turbo situation.

Thanks,
Srinivas

> Pratyush Yadav (2):
>   acpi: processor: allow fixing up the frequency for a performance
> state
>   cpufreq: intel_pstate: use acpi perflib to update turbo frequency
> 
>  drivers/acpi/processor_perflib.c | 40
> ++++++++++++++++++++++++++++++++
>  drivers/cpufreq/intel_pstate.c   |  5 ++--
>  include/acpi/processor.h         |  2 ++
>  3 files changed, 45 insertions(+), 2 deletions(-)
> 
> --
> 2.38.1
>