RE: [PATCH v5 11/13] cpufreq/amd-pstate: Disable preferred cores on designs with workload classification

[Yuan, Perry]

[AMD Official Use Only - AMD Internal Distribution Only]

> -----Original Message-----
> From: Limonciello, Mario <Mario.Limonciello@xxxxxxx>
> Sent: Monday, October 28, 2024 10:03 AM
> To: Borislav Petkov <bp@xxxxxxxxx>; Hans de Goede <hdegoede@xxxxxxxxxx>;
> Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> Cc: x86@xxxxxxxxxx; Shenoy, Gautham Ranjal <gautham.shenoy@xxxxxxx>;
> Limonciello, Mario <Mario.Limonciello@xxxxxxx>; Yuan, Perry
> <Perry.Yuan@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx;
> linux-pm@xxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx; S-k, Shyam-
> sundar <Shyam-sundar.S-k@xxxxxxx>
> Subject: [PATCH v5 11/13] cpufreq/amd-pstate: Disable preferred cores on designs
> with workload classification
>
> On designs that have workload classification, it's preferred that the amd-hfi driver is
> used to provide hints to the scheduler of which cores to use instead of the amd-
> pstate driver.
>
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
>  drivers/cpufreq/amd-pstate.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index
> 32ddbf37a9f0a..c60cc84866982 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -780,6 +780,12 @@ static void amd_pstate_init_prefcore(struct amd_cpudata
> *cpudata)
>       /* user disabled or not detected */
>       if (!amd_pstate_prefcore)
>               return;
> +     /* should use amd-hfi instead */
> +     if (boot_cpu_has(X86_FEATURE_AMD_WORKLOAD_CLASS) &&
> +         IS_ENABLED(CONFIG_AMD_HFI)) {
> +             amd_pstate_prefcore = false;
> +             return;
> +     }
>
>       cpudata->hw_prefcore = true;
>
> --
> 2.43.0

LGTM, the legacy prefer core need to be disabled when HFI loaded.

Reviewed-by: Perry Yuan <perry.yuan@xxxxxxx>