| Message ID | 20221225163442.2205660-3-perry.yuan@amd.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Implement AMD Pstate EPP Driver | expand |
On 12/25/2022 10:34, Perry Yuan 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" > > Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> Reviewed-by: Mario Limonciello <mario.limonciello@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`. >
[AMD Official Use Only - General] Hi Mario. > -----Original Message----- > From: Limonciello, Mario <Mario.Limonciello@amd.com> > Sent: Wednesday, January 4, 2023 8:29 AM > To: Yuan, Perry <Perry.Yuan@amd.com>; rafael.j.wysocki@intel.com; Huang, > Ray <Ray.Huang@amd.com>; viresh.kumar@linaro.org > Cc: Sharma, Deepak <Deepak.Sharma@amd.com>; Fontenot, Nathan > <Nathan.Fontenot@amd.com>; Deucher, Alexander > <Alexander.Deucher@amd.com>; Huang, Shimmer > <Shimmer.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Meng, > Li (Jassmine) <Li.Meng@amd.com>; Karny, Wyes <Wyes.Karny@amd.com>; > linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH v9 02/13] Documentation: amd-pstate: add EPP profiles > introduction > > On 12/25/2022 10:34, Perry Yuan 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_pr > ef > > erences 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> > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > I just got back from sick leave, will pick all your R-B flags and send v10 out. Thank you help to review this version. Perry. > > --- > > 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`. > >
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`.