linux-kernel - Re: [PATCH V1 6/6] Documentation: introduce AMD Pstate Preferrd Core mode kernel command line options

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Date:   Tue, 8 Aug 2023 10:37:06 -0500
From:   Mario Limonciello <mario.limonciello@....com>
To:     Meng Li <li.meng@....com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Huang Rui <ray.huang@....com>
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        x86@...nel.org, linux-acpi@...r.kernel.org,
        Shuah Khan <skhan@...uxfoundation.org>,
        linux-kselftest@...r.kernel.org,
        Nathan Fontenot <nathan.fontenot@....com>,
        Deepak Sharma <deepak.sharma@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Shimmer Huang <shimmer.huang@....com>,
        Perry Yuan <Perry.Yuan@....com>,
        Xiaojian Du <Xiaojian.Du@....com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Borislav Petkov <bp@...en8.de>
Subject: Re: [PATCH V1 6/6] Documentation: introduce AMD Pstate Preferrd Core
 mode kernel command line options

On 8/8/2023 03:10, Meng Li wrote:
> AMD Pstate driver support enable/disable Preferred core.
> Default disabled on platforms supporting AMD Preferred Core.

Why default disabled?

Shouldn't this default enabled and then let users decide they don't want 
to use it if it's causing a problem for them?

> Enable AMD Pstate Preferred Core with
> "amd_prefcore=enable" added to the kernel command line.
> 
> Signed-off-by: Meng Li <li.meng@....com>
> ---
>   Documentation/admin-guide/kernel-parameters.txt | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 2de235d52fac..bc92e178431b 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -363,6 +363,11 @@
>   			  selects a performance level in this range and appropriate
>   			  to the current workload.
>   
> +	amd_prefcore=
> +			[X86]
> +			enable
> +			  Enable AMD Pstate Preferred Core.
> +
>   	amijoy.map=	[HW,JOY] Amiga joystick support
>   			Map of devices attached to JOY0DAT and JOY1DAT
>   			Format: <a>,<b>