Messages in this thread | | | Date | Mon, 19 Dec 2022 16:37:40 -0600 | Subject | Re: [PATCH v8 02/13] Documentation: amd-pstate: add EPP profiles introduction | From | "Limonciello, Mario" <> |
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On 12/19/2022 00:40, Perry Yuan wrote: > From: Perry Yuan <Perry.Yuan@amd.com> > > The patch add AMD pstate EPP feature introduction and what EPP > preference supported for AMD processors.
Don't use "the patch" or "this patch" in the commit message.
I would propose something like this:
> > User can get supported list from > energy_performance_available_preferences attribute file, or update > current profile to energy_performance_preference file
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`. >
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