Commit 6d588891 authored by Perry Yuan's avatar Perry Yuan Committed by Mario Limonciello
Browse files

Documentation: cpufreq: amd-pstate: update doc for Per CPU boost control method 



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.

Reviewed-by: default avatarGautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: default avatarPerry Yuan <perry.yuan@amd.com>
Co-developed-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20240626042733.3747-5-mario.limonciello@amd.com


Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
parent 89ac482d

Documentation/admin-guide/pm/amd-pstate.rst

+16 −0
Original line number Diff line number Diff line
@@ -281,6 +281,22 @@ 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.



Other performance and frequency values can be read back from

``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.