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From: "Limonciello, Mario" <mario.limonciello@amd.com>
To: Perry Yuan <Perry.Yuan@amd.com>,
	rafael.j.wysocki@intel.com, ray.huang@amd.com,
	viresh.kumar@linaro.org
Cc: Deepak.Sharma@amd.com, Nathan.Fontenot@amd.com,
	Alexander.Deucher@amd.com, Shimmer.Huang@amd.com,
	Xiaojian.Du@amd.com, Li.Meng@amd.com, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/8] Documentation: amd-pstate: add EPP profiles introduction
Date: Mon, 7 Nov 2022 12:33:50 -0600	[thread overview]
Message-ID: <8ca9feaa-90c9-93fc-38e0-3c41d51dc845@amd.com> (raw)
In-Reply-To: <20221107175705.2207842-3-Perry.Yuan@amd.com>

On 11/7/2022 11:56, Perry Yuan wrote:
> The patch add AMD pstate EPP feature introduction and what EPP
> preference supported for AMD processors.
> 
> User can get supported list from
> energy_performance_available_preferences attribute file, or update
> current profile to energy_performance_preference file
> 
> 1) See all EPP profiles
> $ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_available_preferences
> default performance balance_performance balance_power power
> 
> 2) Check current EPP profile
> $ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference
> performance
> 
> 3) Set new EPP profile
> $ sudo bash -c "echo power > /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference"
> 
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
> ---
>   Documentation/admin-guide/pm/amd-pstate.rst | 19 +++++++++++++++++++
>   1 file changed, 19 insertions(+)
> 
> diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
> index 8f3d30c5a0d8..78c6525d5a49 100644
> --- a/Documentation/admin-guide/pm/amd-pstate.rst
> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
> @@ -262,6 +262,25 @@ lowest non-linear performance in `AMD CPPC Performance Capability
>   <perf_cap_>`_.)
>   This attribute is read-only.
>   > +``energy_performance_available_preferences``
> +
> +All the supported EPP preference could be selected, List of the strings that
> +can be set to the ``energy_performance_preference`` attribute
> +those different profiles represent different energy vs efficiency hints provided
> +to low-level firmware
> +however, the ``default`` represents the epp value is set by platform firmware
> +This attribute is read-only.

My proposal at rewording it.

A list of all the supported EPP preferences that could be used for 
``energy_performance_preference` on this system.
These profiles represent different hints that are provided
to the low-level firmware about the user's desired energy vs efficiency 
tradeoff.  ``default`` represents the epp value is set by platform 
firmware. This attribute is read-only.


> +
> +``energy_performance_preference``
> +
> +The current energy performance preference can be read from this attribute.
> +and user can change current preference according to energy or performance needs
> +Please get all support profiles list from
> +``energy_performance_available_preferences`` attribute, all the profiles are
> +integer values defined between 0 to 255 when EPP feature is enabled by platform
> +firmware, if EPP feature is disabled, driver will ignore the written value
> +This attribute is read-write.
> +
>   Other performance and frequency values can be read back from
>   ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.
>   


  reply	other threads:[~2022-11-07 18:34 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-07 17:56 [PATCH v3 0/8] Implement AMD Pstate EPP Driver Perry Yuan
2022-11-07 17:56 ` [PATCH v3 1/8] ACPI: CPPC: Add AMD pstate energy performance preference cppc control Perry Yuan
2022-11-07 18:44   ` Limonciello, Mario
2022-11-10 14:49     ` Rafael J. Wysocki
2022-11-10 15:51       ` Yuan, Perry
2022-11-10 15:55         ` Rafael J. Wysocki
2022-11-10 16:23           ` Yuan, Perry
2022-11-13 16:28     ` Yuan, Perry
2022-11-07 17:56 ` [PATCH v3 2/8] Documentation: amd-pstate: add EPP profiles introduction Perry Yuan
2022-11-07 18:33   ` Limonciello, Mario [this message]
2022-11-13 16:23     ` Yuan, Perry
2022-11-10 14:57   ` Rafael J. Wysocki
2022-11-10 15:07     ` Yuan, Perry
2022-11-07 17:57 ` [PATCH v3 3/8] cpufreq: amd-pstate: change driver to be built-in type Perry Yuan
2022-11-07 18:29   ` Limonciello, Mario
2022-11-13 16:21     ` Yuan, Perry
2022-11-07 17:57 ` [PATCH v3 4/8] cpufreq: amd_pstate: add AMD Pstate EPP support for the MSR based processors Perry Yuan
2022-11-07 20:32   ` Limonciello, Mario
2022-11-10 15:59     ` Nathan Fontenot
2022-11-10 16:22       ` Yuan, Perry
2022-11-08  7:21   ` kernel test robot
2022-11-09  5:55   ` kernel test robot
2022-11-07 17:57 ` [PATCH v3 5/8] cpufreq: amd_pstate: implement amd pstate cpu online and offline callback Perry Yuan
2022-11-07 18:22   ` Limonciello, Mario
2022-11-13 16:19     ` Yuan, Perry
2022-11-07 17:57 ` [PATCH v3 6/8] cpufreq: amd-pstate: implement suspend and resume callbacks Perry Yuan
2022-11-07 18:18   ` Limonciello, Mario
2022-11-13 16:19     ` Yuan, Perry
2022-11-10 16:19   ` Nathan Fontenot
2022-11-07 17:57 ` [PATCH v3 7/8] cpufreq: amd-pstate: add frequency dynamic boost sysfs control Perry Yuan
2022-11-07 18:16   ` Limonciello, Mario
2022-11-07 19:09     ` Limonciello, Mario
2022-11-07 17:57 ` [PATCH v3 8/8] cpufreq: amd_pstate: add driver working mode status sysfs entry Perry Yuan
2022-11-07 18:10   ` Limonciello, Mario
2022-11-13 16:18     ` Yuan, Perry
2022-11-10 16:06   ` Nathan Fontenot
2022-11-10 16:49     ` Yuan, Perry

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