linux-kernel - Re: [PATCH v4 11/13] cpufreq/amd-pstate: Disable preferred cores on designs with workload classification

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Message-ID: <ZxdHypzMIW5XW2nI@BLRRASHENOY1.amd.com>
Date: Tue, 22 Oct 2024 12:05:54 +0530
From: "Gautham R. Shenoy" <gautham.shenoy@....com>
To: Mario Limonciello <mario.limonciello@....com>
Cc: Borislav Petkov <bp@...en8.de>, Hans de Goede <hdegoede@...hat.com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	x86@...nel.org, Perry Yuan <perry.yuan@....com>,
	linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
	linux-pm@...r.kernel.org, platform-driver-x86@...r.kernel.org,
	Shyam Sundar S K <Shyam-sundar.S-k@....com>
Subject: Re: [PATCH v4 11/13] cpufreq/amd-pstate: Disable preferred cores on
 designs with workload classification

Hello Mario,

On Mon, Oct 21, 2024 at 01:02:50PM -0500, Mario Limonciello wrote:
> 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.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
> ---
> v2->v3:
>  * Disable prefcore sysfs file too
> ---
>  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 2670bdcad6eda..4dea5a6f86c11 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -782,6 +782,12 @@ 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;
> +	}

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@....com>

--
Thanks and Regards
gautham.