| Message ID | 20221107175705.2207842-3-Perry.Yuan@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/8] ACPI: CPPC: Add AMD pstate energy performance preference cppc control | expand |
On Mon, Nov 7, 2022 at 7:02 PM Perry Yuan <Perry.Yuan@amd.com> 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. > + > +``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`. > > -- So the interface is the same as for intel_pstate AFAICS, which is good, because it is all consistent. However, there is some code duplication introduced in the subsequent patches and that may be a problem from the perspective of maintaining that consistency in the future. Have you at least considered introducing a common EPP support header file that could be used by both intel_pstate and amd_pstate?
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. + +``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`.
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(+)