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 v9 02/13] Documentation: amd-pstate: add EPP profiles introduction
Date: Mon, 26 Dec 2022 00:34:31 +0800 [thread overview]
Message-ID: <20221225163442.2205660-3-perry.yuan@amd.com> (raw)
In-Reply-To: <20221225163442.2205660-1-perry.yuan@amd.com>
From: Perry Yuan <Perry.Yuan@amd.com>
The amd-pstate driver supports a feature called energy performance
preference (EPP). Add information to the documentation to explain
how users can interact with the sysfs files for this feature.
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:[~2022-12-25 16:35 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-25 16:34 [PATCH v9 00/13] Implement AMD Pstate EPP Driver Perry Yuan
2022-12-25 16:34 ` [PATCH v9 01/13] ACPI: CPPC: Add AMD pstate energy performance preference cppc control Perry Yuan
2023-01-05 5:31 ` Wyes Karny
2023-01-05 6:02 ` Yuan, Perry
2022-12-25 16:34 ` Perry Yuan [this message]
2023-01-04 0:29 ` [PATCH v9 02/13] Documentation: amd-pstate: add EPP profiles introduction Limonciello, Mario
2023-01-05 3:18 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 03/13] cpufreq: intel_pstate: use common macro definition for Energy Preference Performance(EPP) Perry Yuan
2023-01-04 0:31 ` Limonciello, Mario
2023-01-05 5:49 ` Yuan, Perry
2023-01-05 5:56 ` Mario Limonciello
2023-01-05 6:14 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 04/13] cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering Perry Yuan
2022-12-27 2:53 ` Viresh Kumar
2022-12-27 6:32 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 05/13] cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param() Perry Yuan
2023-01-04 0:32 ` Limonciello, Mario
2022-12-25 16:34 ` [PATCH v9 06/13] cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors Perry Yuan
2023-01-04 1:05 ` Limonciello, Mario
2023-01-05 6:20 ` Yuan, Perry
2023-01-06 5:22 ` Wyes Karny
2023-01-06 5:58 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 07/13] cpufreq: amd-pstate: implement amd pstate cpu online and offline callback Perry Yuan
2022-12-25 16:34 ` [PATCH v9 08/13] cpufreq: amd-pstate: implement suspend and resume callbacks Perry Yuan
2022-12-27 2:52 ` Viresh Kumar
2023-01-05 15:08 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 09/13] cpufreq: amd-pstate: add driver working mode switch support Perry Yuan
2023-01-04 1:06 ` Limonciello, Mario
2023-01-05 6:02 ` Wyes Karny
2023-01-05 6:57 ` Yuan, Perry
2023-01-05 7:29 ` Wyes Karny
2023-01-05 16:03 ` Wyes Karny
2023-01-06 2:52 ` Yuan, Perry
2023-01-06 3:46 ` Wyes Karny
2022-12-25 16:34 ` [PATCH v9 10/13] Documentation: amd-pstate: add amd pstate driver mode introduction Perry Yuan
2022-12-25 16:34 ` [PATCH v9 11/13] Documentation: introduce amd pstate active mode kernel command line options Perry Yuan
2022-12-25 16:34 ` [PATCH v9 12/13] cpufreq: amd-pstate: convert sprintf with sysfs_emit() Perry Yuan
2022-12-25 16:34 ` [PATCH v9 13/13] Documentation: amd-pstate: introduce new global sysfs attributes Perry Yuan
2023-01-04 0:35 ` Limonciello, Mario
2023-01-05 6:21 ` Yuan, Perry
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221225163442.2205660-3-perry.yuan@amd.com \
--to=perry.yuan@amd.com \
--cc=Alexander.Deucher@amd.com \
--cc=Deepak.Sharma@amd.com \
--cc=Li.Meng@amd.com \
--cc=Mario.Limonciello@amd.com \
--cc=Nathan.Fontenot@amd.com \
--cc=Shimmer.Huang@amd.com \
--cc=Xiaojian.Du@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=rafael.j.wysocki@intel.com \
--cc=ray.huang@amd.com \
--cc=viresh.kumar@linaro.org \
--cc=wyes.karny@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).