| Message ID | 20230106061420.95715-3-perry.yuan@amd.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Implement AMD Pstate EPP Driver | expand |
On Fri, Jan 06, 2023 at 02:14:10PM +0800, Yuan, Perry wrote: > 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" > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> Acked-by: Huang Rui <ray.huang@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 >
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`.