From: Perry Yuan <perry.yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <Mario.Limonciello@amd.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>, <wyes.karny@amd.com>,
<linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v6 02/11] Documentation: amd-pstate: add EPP profiles introduction
Date: Fri, 2 Dec 2022 15:47:10 +0800 [thread overview]
Message-ID: <20221202074719.623673-3-perry.yuan@amd.com> (raw)
In-Reply-To: <20221202074719.623673-1-perry.yuan@amd.com>
From: Perry Yuan <Perry.Yuan@amd.com>
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 06e23538f79c..33ab8ec8fc2f 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``
+
+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`.
--
2.34.1
next prev parent reply other threads:[~2022-12-02 7:50 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-02 7:47 [PATCH v6 00/11] Implement AMD Pstate EPP Driver Perry Yuan
2022-12-02 7:47 ` [PATCH v6 01/11] ACPI: CPPC: Add AMD pstate energy performance preference cppc control Perry Yuan
2022-12-02 16:58 ` Limonciello, Mario
2022-12-05 15:17 ` Yuan, Perry
2022-12-02 7:47 ` Perry Yuan [this message]
2022-12-02 7:47 ` [PATCH v6 03/11] cpufreq: intel_pstate: use common macro definition for Energy Preference Performance(EPP) Perry Yuan
2022-12-05 11:48 ` Huang Rui
2022-12-05 14:40 ` Yuan, Perry
2022-12-05 16:44 ` Limonciello, Mario
2022-12-08 14:40 ` Yuan, Perry
2022-12-08 16:46 ` Limonciello, Mario
2022-12-02 7:47 ` [PATCH v6 04/11] cpufreq: amd_pstate: implement Pstate EPP support for the AMD processors Perry Yuan
2022-12-02 17:36 ` Limonciello, Mario
2022-12-08 15:51 ` Yuan, Perry
2022-12-03 19:52 ` kernel test robot
2022-12-05 12:22 ` Huang Rui
2022-12-08 15:43 ` Yuan, Perry
2022-12-02 7:47 ` [PATCH v6 05/11] cpufreq: amd_pstate: implement amd pstate cpu online and offline callback Perry Yuan
2022-12-02 7:47 ` [PATCH v6 06/11] cpufreq: amd-pstate: implement suspend and resume callbacks Perry Yuan
2022-12-02 7:47 ` [PATCH v6 07/11] cpufreq: amd-pstate: add frequency dynamic boost sysfs control Perry Yuan
2022-12-02 15:59 ` Limonciello, Mario
2022-12-05 15:19 ` Yuan, Perry
2022-12-02 7:47 ` [PATCH v6 08/11] cpufreq: amd_pstate: add driver working mode status sysfs entry Perry Yuan
2022-12-02 15:57 ` Limonciello, Mario
2022-12-08 15:55 ` Yuan, Perry
2022-12-02 7:47 ` [PATCH v6 09/11] Documentation: amd-pstate: add amd pstate driver mode introduction Perry Yuan
2022-12-02 7:47 ` [PATCH v6 10/11] Documentation: introduce amd pstate active mode kernel command line options Perry Yuan
2022-12-02 7:47 ` [PATCH v6 11/11] cpufreq: amd_pstate: convert sprintf with sysfs_emit() Perry Yuan
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