RE: [PATCH] cpufreq: amd-pstate: fix the highest frequency issue which limit performance

[Yuan, Perry]

[AMD Official Use Only - General]

Hi Rafael

> -----Original Message-----
> From: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> Sent: Wednesday, May 8, 2024 7:59 PM
> To: Yuan, Perry <Perry.Yuan@xxxxxxx>
> Cc: rafael.j.wysocki@xxxxxxxxx; Limonciello, Mario
> <Mario.Limonciello@xxxxxxx>; viresh.kumar@xxxxxxxxxx; Huang, Ray
> <Ray.Huang@xxxxxxx>; Shenoy, Gautham Ranjal
> <gautham.shenoy@xxxxxxx>; Petkov, Borislav
> <Borislav.Petkov@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; Huang, Shimmer
> <Shimmer.Huang@xxxxxxx>; Du, Xiaojian <Xiaojian.Du@xxxxxxx>; Meng,
> Li (Jassmine) <Li.Meng@xxxxxxx>; linux-pm@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] cpufreq: amd-pstate: fix the highest frequency issue
> which limit performance
>
> On Wed, May 8, 2024 at 7:47 AM Perry Yuan <perry.yuan@xxxxxxx> wrote:
> >
> > To address the performance drop issue, an optimization has been
> > implemented. The incorrect highest performance value previously set by
> > the low-level power firmware for AMD CPUs with Family ID 0x19 and
> > Model ID ranging from 0x70 to 0x7F series has been identified as the cause.
> >
> > To resolve this, a check has been implemented to accurately determine
> > the CPU family and model ID. The correct highest performance value is
> > now set and the performance drop caused by the incorrect highest
> > performance value are eliminated.
> >
> > Before the fix, the highest frequency was set to 4200MHz, now it is
> > set to 4971MHz which is correct.
> >
> > CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ
> MHZ
> >   0    0      0    0 0:0:0:0          yes 4971.0000 400.0000  400.0000
> >   1    0      0    0 0:0:0:0          yes 4971.0000 400.0000  400.0000
> >   2    0      0    1 1:1:1:0          yes 4971.0000 400.0000 4865.8140
> >   3    0      0    1 1:1:1:0          yes 4971.0000 400.0000  400.0000
> >
> > v1->v2:
> >  * add test by flag from Gaha Bana
>
> This should go into the section below the tags.
>
> And if you send a v2 of a patch, please indicate that this is a v2 in the subject.
>
> > Fixes: f3a052391822 ("cpufreq: amd-pstate: Enable amd-pstate preferred
> > core support")
> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218759
> > Signed-off-by: Perry Yuan <perry.yuan@xxxxxxx>
> > Co-developed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > Tested-by: Gaha Bana <gahabana@xxxxxxxxx>
> > ---
> >  drivers/cpufreq/amd-pstate.c | 22 +++++++++++++++++++---
> >  1 file changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c
> > b/drivers/cpufreq/amd-pstate.c index 2db095867d03..6a342b0c0140
> 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -50,7 +50,8 @@
> >
> >  #define AMD_PSTATE_TRANSITION_LATENCY  20000
> >  #define AMD_PSTATE_TRANSITION_DELAY    1000
> > -#define AMD_PSTATE_PREFCORE_THRESHOLD  166
> > +#define CPPC_HIGHEST_PERF_PERFORMANCE  196
> > +#define CPPC_HIGHEST_PERF_DEFAULT      166
> >
> >  /*
> >   * TODO: We need more time to fine tune processors with shared memory
> > solution @@ -326,6 +327,21 @@ static inline int amd_pstate_enable(bool
> enable)
> >         return static_call(amd_pstate_enable)(enable);
> >  }
> >
> > +static u32 amd_pstate_highest_perf_set(struct amd_cpudata *cpudata) {
> > +       struct cpuinfo_x86 *c = &cpu_data(0);
> > +
> > +       /*
> > +        * For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
> > +        * the highest performance level is set to 196.
> > +        * https://bugzilla.kernel.org/show_bug.cgi?id=218759
> > +        */
> > +       if (c->x86 == 0x19 && (c->x86_model >= 0x70 && c->x86_model <=
> 0x7f))
> > +               return CPPC_HIGHEST_PERF_PERFORMANCE;
> > +
> > +       return CPPC_HIGHEST_PERF_DEFAULT; }
> > +
> >  static int pstate_init_perf(struct amd_cpudata *cpudata)  {
> >         u64 cap1;
> > @@ -342,7 +358,7 @@ static int pstate_init_perf(struct amd_cpudata
> *cpudata)
> >          * the default max perf.
> >          */
> >         if (cpudata->hw_prefcore)
> > -               highest_perf = AMD_PSTATE_PREFCORE_THRESHOLD;
> > +               highest_perf = amd_pstate_highest_perf_set(cpudata);
> >         else
> >                 highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
> >
> > @@ -366,7 +382,7 @@ static int cppc_init_perf(struct amd_cpudata
> *cpudata)
> >                 return ret;
> >
> >         if (cpudata->hw_prefcore)
> > -               highest_perf = AMD_PSTATE_PREFCORE_THRESHOLD;
> > +               highest_perf = amd_pstate_highest_perf_set(cpudata);
> >         else
> >                 highest_perf = cppc_perf.highest_perf;
> >
> > --
>
> Applied as 6.10 material, thanks!

Thank you,  I forget to update the patch version.


Regards.
Perry