From: Perry Yuan <Perry.Yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <ray.huang@amd.com>,
<viresh.kumar@linaro.org>
Cc: <Deepak.Sharma@amd.com>, <Mario.Limonciello@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>,
Perry Yuan <Perry.Yuan@amd.com>
Subject: [RESEND PATCH V2 5/9] Documentation: amd-pstate: add EPP profiles introduction
Date: Tue, 11 Oct 2022 00:22:44 +0800 [thread overview]
Message-ID: <20221010162248.348141-6-Perry.Yuan@amd.com> (raw)
In-Reply-To: <20221010162248.348141-1-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 83b58eb4ab4d..d0f0e115013b 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -261,6 +261,25 @@ 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.
+
+``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:[~2022-10-10 16:24 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-10 16:22 [RESEND PATCH V2 0/9] Implement AMD Pstate EPP Driver Perry Yuan
2022-10-10 16:22 ` [RESEND PATCH V2 1/9] ACPI: CPPC: Add AMD pstate energy performance preference cppc control Perry Yuan
2022-10-17 9:43 ` Huang Rui
2022-10-10 16:22 ` [RESEND PATCH V2 2/9] cpufreq: amd_pstate: add module parameter to load amd pstate EPP driver Perry Yuan
2022-10-17 9:47 ` Huang Rui
2022-10-20 15:56 ` Yuan, Perry
2022-10-10 16:22 ` [RESEND PATCH V2 3/9] cpufreq: cpufreq: export cpufreq cpu release and acquire Perry Yuan
2022-10-10 16:22 ` [RESEND PATCH V2 4/9] x86/msr: Add the MSR definition for AMD CPPC boost state Perry Yuan
2022-10-17 9:56 ` Huang Rui
2022-10-20 16:01 ` Yuan, Perry
2022-10-20 16:05 ` Limonciello, Mario
2022-10-20 16:08 ` Yuan, Perry
2022-10-21 5:22 ` Huang Rui
2022-10-21 9:37 ` Borislav Petkov
2022-10-24 2:58 ` Yuan, Perry
2022-10-24 2:56 ` Yuan, Perry
2022-10-25 0:32 ` Huang Rui
2022-10-25 13:23 ` Yuan, Perry
2022-10-10 16:22 ` Perry Yuan [this message]
2022-10-10 16:22 ` [RESEND PATCH V2 6/9] cpufreq: amd_pstate: add AMD pstate EPP support for shared memory type processor Perry Yuan
2022-10-17 10:54 ` Huang Rui
2022-10-20 16:04 ` Yuan, Perry
2022-10-25 0:25 ` Huang Rui
2022-10-10 16:22 ` [RESEND PATCH V2 7/9] cpufreq: amd_pstate: add AMD Pstate EPP support for the MSR based processors Perry Yuan
2022-10-11 2:54 ` Viresh Kumar
2022-10-11 5:45 ` Yuan, Perry
2022-10-17 11:17 ` Huang Rui
2022-10-10 16:22 ` [RESEND PATCH V2 8/9] cpufreq: amd_pstate: implement amd pstate cpu online and offline callback Perry Yuan
2022-10-10 16:22 ` [RESEND PATCH V2 9/9] cpufreq: amd-pstate: implement suspend and resume callbacks Perry Yuan
2022-10-12 12:06 ` [RESEND PATCH V2 0/9] Implement AMD Pstate EPP Driver Russell Haley
2022-10-17 7:40 ` Huang Rui
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