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diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 2f066df4ee9c..e1771f2225d5 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -19,7 +19,7 @@ Linux kernel. The new mechanism is based on Collaborative Processor Performance Control (CPPC) which provides finer grain frequency management than legacy ACPI hardware P-States. Current AMD CPU/APU platforms are using the ACPI P-states driver to manage CPU frequency and clocks with switching -only in 3 P-states. CPPC replaces the ACPI P-states controls, allows a +only in 3 P-states. CPPC replaces the ACPI P-states controls and allows a flexible, low-latency interface for the Linux kernel to directly communicate the performance hints to hardware. @@ -27,7 +27,7 @@ communicate the performance hints to hardware. ``ondemand``, etc. to manage the performance hints which are provided by CPPC hardware functionality that internally follows the hardware specification (for details refer to AMD64 Architecture Programmer's Manual -Volume 2: System Programming [1]_). Currently ``amd-pstate`` supports basic +Volume 2: System Programming [1]_). Currently, ``amd-pstate`` supports basic frequency control function according to kernel governors on some of the Zen2 and Zen3 processors, and we will implement more AMD specific functions in future after we verify them on the hardware and SBIOS. @@ -41,9 +41,9 @@ continuous, abstract, and unit-less performance value in a scale that is not tied to a specific performance state / frequency. This is an ACPI standard [2]_ which software can specify application performance goals and hints as a relative target to the infrastructure limits. AMD processors -provides the low latency register model (MSR) instead of AML code +provide the low latency register model (MSR) instead of an AML code interpreter for performance adjustments. ``amd-pstate`` will initialize a -``struct cpufreq_driver`` instance ``amd_pstate_driver`` with the callbacks +``struct cpufreq_driver`` instance, ``amd_pstate_driver``, with the callbacks to manage each performance update behavior. :: Highest Perf ------>+-----------------------+ +-----------------------+ @@ -72,7 +72,7 @@ to manage each performance update behavior. :: Lowest non- | | | | linear perf ------>+-----------------------+ +-----------------------+ | | | | - | | Lowest perf ---->| | + | | Min perf ---->| | | | | | Lowest perf ------>+-----------------------+ +-----------------------+ | | | | @@ -91,26 +91,26 @@ AMD CPPC Performance Capability Highest Performance (RO) ......................... -It is the absolute maximum performance an individual processor may reach, +This is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations and may only be achievable if other platform components -are in a specific state; for example, it may require other processors be in +are in a specific state; for example, it may require other processors to be in an idle state. This would be equivalent to the highest frequencies supported by the processor. Nominal (Guaranteed) Performance (RO) ...................................... -It is the maximum sustained performance level of the processor, assuming -ideal operating conditions. In absence of an external constraint (power, -thermal, etc.) this is the performance level the processor is expected to +This is the maximum sustained performance level of the processor, assuming +ideal operating conditions. In the absence of an external constraint (power, +thermal, etc.), this is the performance level the processor is expected to be able to maintain continuously. All cores/processors are expected to be able to sustain their nominal performance state simultaneously. Lowest non-linear Performance (RO) ................................... -It is the lowest performance level at which nonlinear power savings are +This is the lowest performance level at which nonlinear power savings are achieved, for example, due to the combined effects of voltage and frequency scaling. Above this threshold, lower performance levels should be generally more energy efficient than higher performance levels. This register @@ -119,7 +119,7 @@ effectively conveys the most efficient performance level to ``amd-pstate``. Lowest Performance (RO) ........................ -It is the absolute lowest performance level of the processor. Selecting a +This is the absolute lowest performance level of the processor. Selecting a performance level lower than the lowest nonlinear performance level may cause an efficiency penalty but should reduce the instantaneous power consumption of the processor. @@ -149,14 +149,14 @@ a relative number. This can be expressed as percentage of nominal performance (infrastructure max). Below the nominal sustained performance level, desired performance expresses the average performance level of the processor subject to hardware. Above the nominal performance level, -processor must provide at least nominal performance requested and go higher +the processor must provide at least nominal performance requested and go higher if current operating conditions allow. Energy Performance Preference (EPP) (RW) ......................................... -Provides a hint to the hardware if software wants to bias toward performance -(0x0) or energy efficiency (0xff). +This attribute provides a hint to the hardware if software wants to bias +toward performance (0x0) or energy efficiency (0xff). Key Governors Support @@ -173,35 +173,35 @@ operating frequencies supported by the hardware. Users can check the ``amd-pstate`` mainly supports ``schedutil`` and ``ondemand`` for dynamic frequency control. It is to fine tune the processor configuration on ``amd-pstate`` to the ``schedutil`` with CPU CFS scheduler. ``amd-pstate`` -registers adjust_perf callback to implement the CPPC similar performance -update behavior. It is initialized by ``sugov_start`` and then populate the -CPU's update_util_data pointer to assign ``sugov_update_single_perf`` as -the utilization update callback function in CPU scheduler. CPU scheduler -will call ``cpufreq_update_util`` and assign the target performance -according to the ``struct sugov_cpu`` that utilization update belongs to. -Then ``amd-pstate`` updates the desired performance according to the CPU +registers the adjust_perf callback to implement performance update behavior +similar to CPPC. It is initialized by ``sugov_start`` and then populates the +CPU's update_util_data pointer to assign ``sugov_update_single_perf`` as the +utilization update callback function in the CPU scheduler. The CPU scheduler +will call ``cpufreq_update_util`` and assigns the target performance according +to the ``struct sugov_cpu`` that the utilization update belongs to. +Then, ``amd-pstate`` updates the desired performance according to the CPU scheduler assigned. +.. _processor_support: Processor Support ======================= -The ``amd-pstate`` initialization will fail if the _CPC in ACPI SBIOS is -not existed at the detected processor, and it uses ``acpi_cpc_valid`` to -check the _CPC existence. All Zen based processors support legacy ACPI -hardware P-States function, so while the ``amd-pstate`` fails to be -initialized, the kernel will fall back to initialize ``acpi-cpufreq`` -driver. +The ``amd-pstate`` initialization will fail if the ``_CPC`` entry in the ACPI +SBIOS does not exist in the detected processor. It uses ``acpi_cpc_valid`` +to check the existence of ``_CPC``. All Zen based processors support the legacy +ACPI hardware P-States function, so when ``amd-pstate`` fails initialization, +the kernel will fall back to initialize the ``acpi-cpufreq`` driver. There are two types of hardware implementations for ``amd-pstate``: one is `Full MSR Support <perf_cap_>`_ and another is `Shared Memory Support -<perf_cap_>`_. It can use :c:macro:`X86_FEATURE_CPPC` feature flag (for -details refer to Processor Programming Reference (PPR) for AMD Family -19h Model 51h, Revision A1 Processors [3]_) to indicate the different -types. ``amd-pstate`` is to register different ``static_call`` instances -for different hardware implementations. +<perf_cap_>`_. It can use the :c:macro:`X86_FEATURE_CPPC` feature flag to +indicate the different types. (For details, refer to the Processor Programming +Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors [3]_.) +``amd-pstate`` is to register different ``static_call`` instances for different +hardware implementations. -Currently, some of Zen2 and Zen3 processors support ``amd-pstate``. In the +Currently, some of the Zen2 and Zen3 processors support ``amd-pstate``. In the future, it will be supported on more and more AMD processors. Full MSR Support @@ -210,18 +210,18 @@ Full MSR Support Some new Zen3 processors such as Cezanne provide the MSR registers directly while the :c:macro:`X86_FEATURE_CPPC` CPU feature flag is set. ``amd-pstate`` can handle the MSR register to implement the fast switch -function in ``CPUFreq`` that can shrink latency of frequency control on the -interrupt context. The functions with ``pstate_xxx`` prefix represent the -operations of MSR registers. +function in ``CPUFreq`` that can reduce the latency of frequency control in +interrupt context. The functions with a ``pstate_xxx`` prefix represent the +operations on MSR registers. Shared Memory Support ---------------------- -If :c:macro:`X86_FEATURE_CPPC` CPU feature flag is not set, that means the -processor supports shared memory solution. In this case, ``amd-pstate`` +If the :c:macro:`X86_FEATURE_CPPC` CPU feature flag is not set, the +processor supports the shared memory solution. In this case, ``amd-pstate`` uses the ``cppc_acpi`` helper methods to implement the callback functions -that defined on ``static_call``. The functions with ``cppc_xxx`` prefix -represent the operations of acpi cppc helpers for shared memory solution. +that are defined on ``static_call``. The functions with the ``cppc_xxx`` prefix +represent the operations of ACPI CPPC helpers for the shared memory solution. AMD P-States and ACPI hardware P-States always can be supported in one @@ -230,11 +230,11 @@ with :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_set_enable``, it will respond to the request from AMD P-States. -User Space Interface in ``sysfs`` -================================== +User Space Interface in ``sysfs`` - Per-policy control +====================================================== ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to -control its functionality at the system level. They located in the +control its functionality at the system level. They are located in the ``/sys/devices/system/cpu/cpufreq/policyX/`` directory and affect all CPUs. :: root@hr-test1:/home/ray# ls /sys/devices/system/cpu/cpufreq/policy0/*amd* @@ -246,66 +246,233 @@ control its functionality at the system level. They located in the ``amd_pstate_highest_perf / amd_pstate_max_freq`` Maximum CPPC performance and CPU frequency that the driver is allowed to -set in percent of the maximum supported CPPC performance level (the highest +set, in percent of the maximum supported CPPC performance level (the highest performance supported in `AMD CPPC Performance Capability <perf_cap_>`_). -In some of ASICs, the highest CPPC performance is not the one in the _CPC -table, so we need to expose it to sysfs. If boost is not active but -supported, this maximum frequency will be larger than the one in +In some ASICs, the highest CPPC performance is not the one in the ``_CPC`` +table, so we need to expose it to sysfs. If boost is not active, but +still supported, this maximum frequency will be larger than the one in ``cpuinfo``. This attribute is read-only. ``amd_pstate_lowest_nonlinear_freq`` -The lowest non-linear CPPC CPU frequency that the driver is allowed to set -in percent of the maximum supported CPPC performance level (Please see the +The lowest non-linear CPPC CPU frequency that the driver is allowed to set, +in percent of the maximum supported CPPC performance level. (Please see the lowest non-linear performance in `AMD CPPC Performance Capability -<perf_cap_>`_). +<perf_cap_>`_.) This attribute is read-only. -For other performance and frequency values, we can read them back from +``amd_pstate_hw_prefcore`` + +Whether the platform supports the preferred core feature and it has been +enabled. This attribute is read-only. + +``amd_pstate_prefcore_ranking`` + +The performance ranking of the core. This number doesn't have any unit, but +larger numbers are preferred at the time of reading. This can change at +runtime based on platform conditions. 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. + +``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`. ``amd-pstate`` vs ``acpi-cpufreq`` ====================================== -On majority of AMD platforms supported by ``acpi-cpufreq``, the ACPI tables -provided by the platform firmware used for CPU performance scaling, but -only provides 3 P-states on AMD processors. -However, on modern AMD APU and CPU series, it provides the collaborative -processor performance control according to ACPI protocol and customize this -for AMD platforms. That is fine-grain and continuous frequency range +On the majority of AMD platforms supported by ``acpi-cpufreq``, the ACPI tables +provided by the platform firmware are used for CPU performance scaling, but +only provide 3 P-states on AMD processors. +However, on modern AMD APU and CPU series, hardware provides the Collaborative +Processor Performance Control according to the ACPI protocol and customizes this +for AMD platforms. That is, fine-grained and continuous frequency ranges instead of the legacy hardware P-states. ``amd-pstate`` is the kernel -module which supports the new AMD P-States mechanism on most of future AMD -platforms. The AMD P-States mechanism will be the more performance and energy +module which supports the new AMD P-States mechanism on most of the future AMD +platforms. The AMD P-States mechanism is the more performance and energy efficiency frequency management method on AMD processors. -Kernel Module Options for ``amd-pstate`` -========================================= -``shared_mem`` -Use a module param (shared_mem) to enable related processors manually with -**amd_pstate.shared_mem=1**. -Due to the performance issue on the processors with `Shared Memory Support -<perf_cap_>`_, so we disable it for the moment and will enable this by default -once we address performance issue on this solution. +``amd-pstate`` Driver Operation Modes +====================================== + +``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode, +non-autonomous (passive) mode and guided autonomous (guided) mode. +Active/passive/guided mode can be chosen by different kernel parameters. + +- In autonomous mode, platform ignores the desired performance level request + and takes into account only the values set to the minimum, maximum and energy + performance preference registers. +- In non-autonomous mode, platform gets desired performance level + from OS directly through Desired Performance Register. +- In guided-autonomous mode, platform sets operating performance level + autonomously according to the current workload and within the limits set by + OS through min and max performance registers. + +Active Mode +------------ + +``amd_pstate=active`` + +This is the low-level firmware control mode which is implemented by ``amd_pstate_epp`` +driver with ``amd_pstate=active`` passed to the kernel in the command line. +In this mode, ``amd_pstate_epp`` driver provides a hint to the hardware if software +wants to bias toward performance (0x0) or energy efficiency (0xff) to the CPPC firmware. +then CPPC power algorithm will calculate the runtime workload and adjust the realtime +cores frequency according to the power supply and thermal, core voltage and some other +hardware conditions. + +Passive Mode +------------ + +``amd_pstate=passive`` + +It will be enabled if the ``amd_pstate=passive`` is passed to the kernel in the command line. +In this mode, ``amd_pstate`` driver software specifies a desired QoS target in the CPPC +performance scale as a relative number. This can be expressed as percentage of nominal +performance (infrastructure max). Below the nominal sustained performance level, +desired performance expresses the average performance level of the processor subject +to the Performance Reduction Tolerance register. Above the nominal performance level, +processor must provide at least nominal performance requested and go higher if current +operating conditions allow. + +Guided Mode +----------- + +``amd_pstate=guided`` + +If ``amd_pstate=guided`` is passed to kernel command line option then this mode +is activated. In this mode, driver requests minimum and maximum performance +level and the platform autonomously selects a performance level in this range +and appropriate to the current workload. + +``amd-pstate`` Preferred Core +================================= + +The core frequency is subjected to the process variation in semiconductors. +Not all cores are able to reach the maximum frequency respecting the +infrastructure limits. Consequently, AMD has redefined the concept of +maximum frequency of a part. This means that a fraction of cores can reach +maximum frequency. To find the best process scheduling policy for a given +scenario, OS needs to know the core ordering informed by the platform through +highest performance capability register of the CPPC interface. + +``amd-pstate`` preferred core enables the scheduler to prefer scheduling on +cores that can achieve a higher frequency with lower voltage. The preferred +core rankings can dynamically change based on the workload, platform conditions, +thermals and ageing. + +The priority metric will be initialized by the ``amd-pstate`` driver. The ``amd-pstate`` +driver will also determine whether or not ``amd-pstate`` preferred core is +supported by the platform. + +``amd-pstate`` driver will provide an initial core ordering when the system boots. +The platform uses the CPPC interfaces to communicate the core ranking to the +operating system and scheduler to make sure that OS is choosing the cores +with highest performance firstly for scheduling the process. When ``amd-pstate`` +driver receives a message with the highest performance change, it will +update the core ranking and set the cpu's priority. + +``amd-pstate`` Preferred Core Switch +===================================== +Kernel Parameters +----------------- + +``amd-pstate`` peferred core`` has two states: enable and disable. +Enable/disable states can be chosen by different kernel parameters. +Default enable ``amd-pstate`` preferred core. + +``amd_prefcore=disable`` + +For systems that support ``amd-pstate`` preferred core, the core rankings will +always be advertised by the platform. But OS can choose to ignore that via the +kernel parameter ``amd_prefcore=disable``. + +User Space Interface in ``sysfs`` - General +=========================================== + +Global Attributes +----------------- + +``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to +control its functionality at the system level. They are located in the +``/sys/devices/system/cpu/amd_pstate/`` directory and affect all CPUs. + +``status`` + Operation mode of the driver: "active", "passive", "guided" or "disable". + + "active" + The driver is functional and in the ``active mode`` + + "passive" + The driver is functional and in the ``passive mode`` -The way to check whether current processor is `Full MSR Support <perf_cap_>`_ -or `Shared Memory Support <perf_cap_>`_ : :: + "guided" + The driver is functional and in the ``guided mode`` - ray@hr-test1:~$ lscpu | grep cppc - Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd cppc arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip pku ospke vaes vpclmulqdq rdpid overflow_recov succor smca fsrm + "disable" + The driver is unregistered and not functional now. -If CPU Flags have cppc, then this processor supports `Full MSR Support -<perf_cap_>`_. Otherwise it supports `Shared Memory Support <perf_cap_>`_. + This attribute can be written to in order to change the driver's + operation mode or to unregister it. The string written to it must be + one of the possible values of it and, if successful, writing one of + these values to the sysfs file will cause the driver to switch over + to the operation mode represented by that string - or to be + unregistered in the "disable" case. +``prefcore`` + Preferred core state of the driver: "enabled" or "disabled". + + "enabled" + Enable the ``amd-pstate`` preferred core. + + "disabled" + Disable the ``amd-pstate`` preferred core + + + This attribute is read-only to check the state of preferred core set + by the kernel parameter. ``cpupower`` tool support for ``amd-pstate`` =============================================== -``amd-pstate`` is supported on ``cpupower`` tool that can be used to dump the frequency -information. And it is in progress to support more and more operations for new -``amd-pstate`` module with this tool. :: +``amd-pstate`` is supported by the ``cpupower`` tool, which can be used to dump +frequency information. Development is in progress to support more and more +operations for the new ``amd-pstate`` module with this tool. :: root@hr-test1:/home/ray# cpupower frequency-info analyzing CPU 0: @@ -336,10 +503,10 @@ Trace Events -------------- There are two static trace events that can be used for ``amd-pstate`` -diagnostics. One of them is the cpu_frequency trace event generally used +diagnostics. One of them is the ``cpu_frequency`` trace event generally used by ``CPUFreq``, and the other one is the ``amd_pstate_perf`` trace event specific to ``amd-pstate``. The following sequence of shell commands can -be used to enable them and see their output (if the kernel is generally +be used to enable them and see their output (if the kernel is configured to support event tracing). :: root@hr-test1:/home/ray# cd /sys/kernel/tracing/ @@ -364,11 +531,261 @@ configured to support event tracing). :: <idle>-0 [003] d.s.. 4995.980971: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=3 changed=false fast_switch=true <idle>-0 [011] d.s.. 4995.980996: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=11 changed=false fast_switch=true -The cpu_frequency trace event will be triggered either by the ``schedutil`` scaling +The ``cpu_frequency`` trace event will be triggered either by the ``schedutil`` scaling governor (for the policies it is attached to), or by the ``CPUFreq`` core (for the policies with other scaling governors). +Tracer Tool +------------- + +``amd_pstate_tracer.py`` can record and parse ``amd-pstate`` trace log, then +generate performance plots. This utility can be used to debug and tune the +performance of ``amd-pstate`` driver. The tracer tool needs to import intel +pstate tracer. + +Tracer tool located in ``linux/tools/power/x86/amd_pstate_tracer``. It can be +used in two ways. If trace file is available, then directly parse the file +with command :: + + ./amd_pstate_trace.py [-c cpus] -t <trace_file> -n <test_name> + +Or generate trace file with root privilege, then parse and plot with command :: + + sudo ./amd_pstate_trace.py [-c cpus] -n <test_name> -i <interval> [-m kbytes] + +The test result can be found in ``results/test_name``. Following is the example +about part of the output. :: + + common_cpu common_secs common_usecs min_perf des_perf max_perf freq mperf apef tsc load duration_ms sample_num elapsed_time common_comm + CPU_005 712 116384 39 49 166 0.7565 9645075 2214891 38431470 25.1 11.646 469 2.496 kworker/5:0-40 + CPU_006 712 116408 39 49 166 0.6769 8950227 1839034 37192089 24.06 11.272 470 2.496 kworker/6:0-1264 + +Unit Tests for amd-pstate +------------------------- + +``amd-pstate-ut`` is a test module for testing the ``amd-pstate`` driver. + + * It can help all users to verify their processor support (SBIOS/Firmware or Hardware). + + * Kernel can have a basic function test to avoid the kernel regression during the update. + + * We can introduce more functional or performance tests to align the result together, it will benefit power and performance scale optimization. + +1. Test case descriptions + + 1). Basic tests + + Test prerequisite and basic functions for the ``amd-pstate`` driver. + + +---------+--------------------------------+------------------------------------------------------------------------------------+ + | Index | Functions | Description | + +=========+================================+====================================================================================+ + | 1 | amd_pstate_ut_acpi_cpc_valid || Check whether the _CPC object is present in SBIOS. | + | | || | + | | || The detail refer to `Processor Support <processor_support_>`_. | + +---------+--------------------------------+------------------------------------------------------------------------------------+ + | 2 | amd_pstate_ut_check_enabled || Check whether AMD P-State is enabled. | + | | || | + | | || AMD P-States and ACPI hardware P-States always can be supported in one processor. | + | | | But AMD P-States has the higher priority and if it is enabled with | + | | | :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_set_enable``, it will respond to the | + | | | request from AMD P-States. | + +---------+--------------------------------+------------------------------------------------------------------------------------+ + | 3 | amd_pstate_ut_check_perf || Check if the each performance values are reasonable. | + | | || highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0. | + +---------+--------------------------------+------------------------------------------------------------------------------------+ + | 4 | amd_pstate_ut_check_freq || Check if the each frequency values and max freq when set support boost mode | + | | | are reasonable. | + | | || max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0 | + | | || If boost is not active but supported, this maximum frequency will be larger than | + | | | the one in ``cpuinfo``. | + +---------+--------------------------------+------------------------------------------------------------------------------------+ + + 2). Tbench test + + Test and monitor the cpu changes when running tbench benchmark under the specified governor. + These changes include desire performance, frequency, load, performance, energy etc. + The specified governor is ondemand or schedutil. + Tbench can also be tested on the ``acpi-cpufreq`` kernel driver for comparison. + + 3). Gitsource test + + Test and monitor the cpu changes when running gitsource benchmark under the specified governor. + These changes include desire performance, frequency, load, time, energy etc. + The specified governor is ondemand or schedutil. + Gitsource can also be tested on the ``acpi-cpufreq`` kernel driver for comparison. + +#. How to execute the tests + + We use test module in the kselftest frameworks to implement it. + We create ``amd-pstate-ut`` module and tie it into kselftest.(for + details refer to Linux Kernel Selftests [4]_). + + 1). Build + + + open the :c:macro:`CONFIG_X86_AMD_PSTATE` configuration option. + + set the :c:macro:`CONFIG_X86_AMD_PSTATE_UT` configuration option to M. + + make project + + make selftest :: + + $ cd linux + $ make -C tools/testing/selftests + + + make perf :: + + $ cd tools/perf/ + $ make + + + 2). Installation & Steps :: + + $ make -C tools/testing/selftests install INSTALL_PATH=~/kselftest + $ cp tools/perf/perf /usr/bin/perf + $ sudo ./kselftest/run_kselftest.sh -c amd-pstate + + 3). Specified test case :: + + $ cd ~/kselftest/amd-pstate + $ sudo ./run.sh -t basic + $ sudo ./run.sh -t tbench + $ sudo ./run.sh -t tbench -m acpi-cpufreq + $ sudo ./run.sh -t gitsource + $ sudo ./run.sh -t gitsource -m acpi-cpufreq + $ ./run.sh --help + ./run.sh: illegal option -- - + Usage: ./run.sh [OPTION...] + [-h <help>] + [-o <output-file-for-dump>] + [-c <all: All testing, + basic: Basic testing, + tbench: Tbench testing, + gitsource: Gitsource testing.>] + [-t <tbench time limit>] + [-p <tbench process number>] + [-l <loop times for tbench>] + [-i <amd tracer interval>] + [-m <comparative test: acpi-cpufreq>] + + + 4). Results + + + basic + + When you finish test, you will get the following log info :: + + $ dmesg | grep "amd_pstate_ut" | tee log.txt + [12977.570663] amd_pstate_ut: 1 amd_pstate_ut_acpi_cpc_valid success! + [12977.570673] amd_pstate_ut: 2 amd_pstate_ut_check_enabled success! + [12977.571207] amd_pstate_ut: 3 amd_pstate_ut_check_perf success! + [12977.571212] amd_pstate_ut: 4 amd_pstate_ut_check_freq success! + + + tbench + + When you finish test, you will get selftest.tbench.csv and png images. + The selftest.tbench.csv file contains the raw data and the drop of the comparative test. + The png images shows the performance, energy and performan per watt of each test. + Open selftest.tbench.csv : + + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + Governor | Round | Des-perf | Freq | Load | Performance | Energy | Performance Per Watt | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + Unit | | | GHz | | MB/s | J | MB/J | + +=================================================+==============+==========+=========+==========+=============+=========+======================+ + + amd-pstate-ondemand | 1 | | | | 2504.05 | 1563.67 | 158.5378 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand | 2 | | | | 2243.64 | 1430.32 | 155.2941 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand | 3 | | | | 2183.88 | 1401.32 | 154.2860 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand | Average | | | | 2310.52 | 1465.1 | 156.1268 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | 1 | 165.329 | 1.62257 | 99.798 | 2136.54 | 1395.26 | 151.5971 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | 2 | 166 | 1.49761 | 99.9993 | 2100.56 | 1380.5 | 150.6377 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | 3 | 166 | 1.47806 | 99.9993 | 2084.12 | 1375.76 | 149.9737 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | Average | 165.776 | 1.53275 | 99.9322 | 2107.07 | 1383.84 | 150.7399 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | 1 | | | | 2529.9 | 1564.4 | 160.0997 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | 2 | | | | 2249.76 | 1432.97 | 155.4297 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | 3 | | | | 2181.46 | 1406.88 | 153.5060 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | Average | | | | 2320.37 | 1468.08 | 156.4741 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | 1 | | | | 2137.64 | 1385.24 | 152.7723 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | 2 | | | | 2107.05 | 1372.23 | 152.0138 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | 3 | | | | 2085.86 | 1365.35 | 151.2433 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | Average | | | | 2110.18 | 1374.27 | 152.0136 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand VS acpi-cpufreq-schedutil | Comprison(%) | | | | -9.0584 | -6.3899 | -2.8506 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | | | | 8.8053 | -5.5463 | -3.4503 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | | -0.4245 | -0.2029 | -0.2219 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | | -0.1473 | 0.6963 | -0.8378 | + +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+ + + + gitsource + + When you finish test, you will get selftest.gitsource.csv and png images. + The selftest.gitsource.csv file contains the raw data and the drop of the comparative test. + The png images shows the performance, energy and performan per watt of each test. + Open selftest.gitsource.csv : + + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + Governor | Round | Des-perf | Freq | Load | Time | Energy | Performance Per Watt | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + Unit | | | GHz | | s | J | 1/J | + +=================================================+==============+==========+==========+==========+=============+=========+======================+ + + amd-pstate-ondemand | 1 | 50.119 | 2.10509 | 23.3076 | 475.69 | 865.78 | 0.001155027 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand | 2 | 94.8006 | 1.98771 | 56.6533 | 467.1 | 839.67 | 0.001190944 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand | 3 | 76.6091 | 2.53251 | 43.7791 | 467.69 | 855.85 | 0.001168429 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand | Average | 73.8429 | 2.20844 | 41.2467 | 470.16 | 853.767 | 0.001171279 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | 1 | 165.919 | 1.62319 | 98.3868 | 464.17 | 866.8 | 0.001153668 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | 2 | 165.97 | 1.31309 | 99.5712 | 480.15 | 880.4 | 0.001135847 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | 3 | 165.973 | 1.28448 | 99.9252 | 481.79 | 867.02 | 0.001153375 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-schedutil | Average | 165.954 | 1.40692 | 99.2944 | 475.37 | 871.407 | 0.001147569 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | 1 | | | | 2379.62 | 742.96 | 0.001345967 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | 2 | | | | 441.74 | 817.49 | 0.001223256 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | 3 | | | | 455.48 | 820.01 | 0.001219497 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand | Average | | | | 425.613 | 793.487 | 0.001260260 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | 1 | | | | 459.69 | 838.54 | 0.001192548 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | 2 | | | | 466.55 | 830.89 | 0.001203528 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | 3 | | | | 470.38 | 837.32 | 0.001194286 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil | Average | | | | 465.54 | 835.583 | 0.001196769 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand VS acpi-cpufreq-schedutil | Comprison(%) | | | | 9.3810 | 5.3051 | -5.0379 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | 124.7392 | -36.2934 | 140.7329 | 1.1081 | 2.0661 | -2.0242 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | | 10.4665 | 7.5968 | -7.0605 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + + acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | | 2.1115 | 4.2873 | -4.1110 | + +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+ + Reference =========== @@ -380,3 +797,6 @@ Reference .. [3] Processor Programming Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip + +.. [4] Linux Kernel Selftests, + https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html |