Lines Matching refs:amd
5 ``amd-pstate`` CPU Performance Scaling Driver
10 :Author: Huang Rui <ray.huang@amd.com>
16 ``amd-pstate`` is the AMD CPU performance scaling driver that introduces a
26 ``amd-pstate`` leverages the Linux kernel governors such as ``schedutil``,
30 Volume 2: System Programming [1]_). Currently, ``amd-pstate`` supports basic
45 interpreter for performance adjustments. ``amd-pstate`` will initialize a
117 effectively conveys the most efficient performance level to ``amd-pstate``.
130 ``amd-pstate`` passes performance goals through these registers. The
136 ``amd-pstate`` specifies the minimum allowed performance level.
141 ``amd-pstate`` specifies a limit the maximum performance that is expected
147 ``amd-pstate`` specifies a desired target in the CPPC performance scale as
165 ``amd-pstate`` can be used with all the (generic) scaling governors listed
173 ``amd-pstate`` mainly supports ``schedutil`` and ``ondemand`` for dynamic
175 ``amd-pstate`` to the ``schedutil`` with CPU CFS scheduler. ``amd-pstate``
182 Then, ``amd-pstate`` updates the desired performance according to the CPU
190 The ``amd-pstate`` initialization will fail if the ``_CPC`` entry in the ACPI
193 ACPI hardware P-States function, so when ``amd-pstate`` fails initialization,
196 There are two types of hardware implementations for ``amd-pstate``: one is
201 ``amd-pstate`` is to register different ``static_call`` instances for different
204 Currently, some of the Zen2 and Zen3 processors support ``amd-pstate``. In the
212 ``amd-pstate`` can handle the MSR register to implement the fast switch
221 processor supports the shared memory solution. In this case, ``amd-pstate``
236 ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to
240 root@hr-test1:/home/ray# ls /sys/devices/system/cpu/cpufreq/policy0/*amd*
317 ``amd-pstate`` vs ``acpi-cpufreq``
326 instead of the legacy hardware P-states. ``amd-pstate`` is the kernel
332 ``amd-pstate`` Driver Operation Modes
385 ``amd-pstate`` Preferred Core
396 ``amd-pstate`` preferred core enables the scheduler to prefer scheduling on
401 The priority metric will be initialized by the ``amd-pstate`` driver. The ``amd-pstate``
402 driver will also determine whether or not ``amd-pstate`` preferred core is
405 ``amd-pstate`` driver will provide an initial core ordering when the system boots.
408 with highest performance firstly for scheduling the process. When ``amd-pstate``
412 ``amd-pstate`` Preferred Core Switch
417 ``amd-pstate`` peferred core`` has two states: enable and disable.
419 Default enable ``amd-pstate`` preferred core.
423 For systems that support ``amd-pstate`` preferred core, the core rankings will
433 ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to
463 Enable the ``amd-pstate`` preferred core.
466 Disable the ``amd-pstate`` preferred core
472 ``cpupower`` tool support for ``amd-pstate``
475 ``amd-pstate`` is supported by the ``cpupower`` tool, which can be used to dump
477 operations for the new ``amd-pstate`` module with this tool. ::
481 driver: amd-pstate
507 There are two static trace events that can be used for ``amd-pstate``
510 specific to ``amd-pstate``. The following sequence of shell commands can
544 ``amd_pstate_tracer.py`` can record and parse ``amd-pstate`` trace log, then
546 performance of ``amd-pstate`` driver. The tracer tool needs to import intel
566 Unit Tests for amd-pstate
569 ``amd-pstate-ut`` is a test module for testing the ``amd-pstate`` driver.
581 Test prerequisite and basic functions for the ``amd-pstate`` driver.
624 We create ``amd-pstate-ut`` module and tie it into kselftest.(for
647 $ sudo ./kselftest/run_kselftest.sh -c amd-pstate
651 $ cd ~/kselftest/amd-pstate
669 [-i <amd tracer interval>]
697 …+ amd-pstate-ondemand | 1 | | | |…
699 …+ amd-pstate-ondemand | 2 | | | |…
701 …+ amd-pstate-ondemand | 3 | | | |…
703 …+ amd-pstate-ondemand | Average | | | |…
705 …+ amd-pstate-schedutil | 1 | 165.329 | 1.62257 | 99.798 |…
707 …+ amd-pstate-schedutil | 2 | 166 | 1.49761 | 99.9993 |…
709 …+ amd-pstate-schedutil | 3 | 166 | 1.47806 | 99.9993 |…
711 …+ amd-pstate-schedutil | Average | 165.776 | 1.53275 | 99.9322 |…
731 …+ amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | | | |…
733 …+ acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | |…
735 …+ acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | |…
750 …+ amd-pstate-ondemand | 1 | 50.119 | 2.10509 | 23.3076 …
752 …+ amd-pstate-ondemand | 2 | 94.8006 | 1.98771 | 56.6533 …
754 …+ amd-pstate-ondemand | 3 | 76.6091 | 2.53251 | 43.7791 …
756 …+ amd-pstate-ondemand | Average | 73.8429 | 2.20844 | 41.2467 …
758 …+ amd-pstate-schedutil | 1 | 165.919 | 1.62319 | 98.3868 …
760 …+ amd-pstate-schedutil | 2 | 165.97 | 1.31309 | 99.5712 …
762 …+ amd-pstate-schedutil | 3 | 165.973 | 1.28448 | 99.9252 …
764 …+ amd-pstate-schedutil | Average | 165.954 | 1.40692 | 99.2944 …
784 …+ amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | 124.7392 | -36.2934 | 140.7329 …
786 …+ acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | …
788 …+ acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | …
795 https://www.amd.com/system/files/TechDocs/24593.pdf
801 https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip