Messages in this thread Patch in this message | | | From | Perry Yuan <> | Subject | [PATCH v10 7/7] Documentation: cpufreq: amd-pstate: update doc for Per CPU boost control method | Date | Wed, 8 May 2024 15:21:12 +0800 |
| |
Updates the documentation in `amd-pstate.rst` to include information about the per CPU boost control feature. Users can now enable or disable the Core Performance Boost (CPB) feature on individual CPUs using the `boost` sysfs attribute.
Signed-off-by: Perry Yuan <perry.yuan@amd.com> --- Documentation/admin-guide/pm/amd-pstate.rst | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index bcc0d9404c18..98e43c53c387 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -281,6 +281,26 @@ 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. +``boost`` +The `boost` sysfs attribute provides control over the CPU core +performance boost, allowing users to manage the maximum frequency limitation +of the CPU. This attribute can be used to enable or disable the boost feature +on individual CPUs. + +When the boost feature is enabled, the CPU can dynamically increase its frequency +beyond the base frequency, providing enhanced performance for demanding workloads. +On the other hand, disabling the boost feature restricts the CPU to operate at the +base frequency, which may be desirable in certain scenarios to prioritize power +efficiency or manage temperature. + +To manipulate the `boost` attribute, users can write a value of `0` to disable the +boost or `1` to enable it, for the respective CPU using the sysfs path +`/sys/devices/system/cpu/cpuX/cpufreq/boost`, where `X` represents the CPU number. + +It is important to note that modifying the global variable +`amd_pstate_global_params.cpb_boost` will override the individual CPU settings. + + Other performance and frequency values can be read back from ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`. -- 2.34.1
| |