1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 .. include:: <isonum.txt> 2 .. include:: <isonum.txt>
3 3
4 ============================================== 4 ===============================================
5 ``amd-pstate`` CPU Performance Scaling Driver 5 ``amd-pstate`` CPU Performance Scaling Driver
6 ============================================== 6 ===============================================
7 7
8 :Copyright: |copy| 2021 Advanced Micro Devices 8 :Copyright: |copy| 2021 Advanced Micro Devices, Inc.
9 9
10 :Author: Huang Rui <ray.huang@amd.com> 10 :Author: Huang Rui <ray.huang@amd.com>
11 11
12 12
13 Introduction 13 Introduction
14 =================== 14 ===================
15 15
16 ``amd-pstate`` is the AMD CPU performance scal 16 ``amd-pstate`` is the AMD CPU performance scaling driver that introduces a
17 new CPU frequency control mechanism on modern 17 new CPU frequency control mechanism on modern AMD APU and CPU series in
18 Linux kernel. The new mechanism is based on Co 18 Linux kernel. The new mechanism is based on Collaborative Processor
19 Performance Control (CPPC) which provides fine 19 Performance Control (CPPC) which provides finer grain frequency management
20 than legacy ACPI hardware P-States. Current AM 20 than legacy ACPI hardware P-States. Current AMD CPU/APU platforms are using
21 the ACPI P-states driver to manage CPU frequen 21 the ACPI P-states driver to manage CPU frequency and clocks with switching
22 only in 3 P-states. CPPC replaces the ACPI P-s 22 only in 3 P-states. CPPC replaces the ACPI P-states controls and allows a
23 flexible, low-latency interface for the Linux 23 flexible, low-latency interface for the Linux kernel to directly
24 communicate the performance hints to hardware. 24 communicate the performance hints to hardware.
25 25
26 ``amd-pstate`` leverages the Linux kernel gove 26 ``amd-pstate`` leverages the Linux kernel governors such as ``schedutil``,
27 ``ondemand``, etc. to manage the performance h 27 ``ondemand``, etc. to manage the performance hints which are provided by
28 CPPC hardware functionality that internally fo 28 CPPC hardware functionality that internally follows the hardware
29 specification (for details refer to AMD64 Arch 29 specification (for details refer to AMD64 Architecture Programmer's Manual
30 Volume 2: System Programming [1]_). Currently, 30 Volume 2: System Programming [1]_). Currently, ``amd-pstate`` supports basic
31 frequency control function according to kernel 31 frequency control function according to kernel governors on some of the
32 Zen2 and Zen3 processors, and we will implemen 32 Zen2 and Zen3 processors, and we will implement more AMD specific functions
33 in future after we verify them on the hardware 33 in future after we verify them on the hardware and SBIOS.
34 34
35 35
36 AMD CPPC Overview 36 AMD CPPC Overview
37 ======================= 37 =======================
38 38
39 Collaborative Processor Performance Control (C 39 Collaborative Processor Performance Control (CPPC) interface enumerates a
40 continuous, abstract, and unit-less performanc 40 continuous, abstract, and unit-less performance value in a scale that is
41 not tied to a specific performance state / fre 41 not tied to a specific performance state / frequency. This is an ACPI
42 standard [2]_ which software can specify appli 42 standard [2]_ which software can specify application performance goals and
43 hints as a relative target to the infrastructu 43 hints as a relative target to the infrastructure limits. AMD processors
44 provide the low latency register model (MSR) i 44 provide the low latency register model (MSR) instead of an AML code
45 interpreter for performance adjustments. ``amd 45 interpreter for performance adjustments. ``amd-pstate`` will initialize a
46 ``struct cpufreq_driver`` instance, ``amd_psta 46 ``struct cpufreq_driver`` instance, ``amd_pstate_driver``, with the callbacks
47 to manage each performance update behavior. :: 47 to manage each performance update behavior. ::
48 48
49 Highest Perf ------>+-----------------------+ 49 Highest Perf ------>+-----------------------+ +-----------------------+
50 | | 50 | | | |
51 | | 51 | | | |
52 | | 52 | | Max Perf ---->| |
53 | | 53 | | | |
54 | | 54 | | | |
55 Nominal Perf ------>+-----------------------+ 55 Nominal Perf ------>+-----------------------+ +-----------------------+
56 | | 56 | | | |
57 | | 57 | | | |
58 | | 58 | | | |
59 | | 59 | | | |
60 | | 60 | | | |
61 | | 61 | | | |
62 | | 62 | | Desired Perf ---->| |
63 | | 63 | | | |
64 | | 64 | | | |
65 | | 65 | | | |
66 | | 66 | | | |
67 | | 67 | | | |
68 | | 68 | | | |
69 | | 69 | | | |
70 | | 70 | | | |
71 | | 71 | | | |
72 Lowest non- | | 72 Lowest non- | | | |
73 linear perf ------>+-----------------------+ 73 linear perf ------>+-----------------------+ +-----------------------+
74 | | 74 | | | |
75 | | 75 | | Lowest perf ---->| |
76 | | 76 | | | |
77 Lowest perf ------>+-----------------------+ 77 Lowest perf ------>+-----------------------+ +-----------------------+
78 | | 78 | | | |
79 | | 79 | | | |
80 | | 80 | | | |
81 0 ------>+-----------------------+ 81 0 ------>+-----------------------+ +-----------------------+
82 82
83 AMD P-Sta 83 AMD P-States Performance Scale
84 84
85 85
86 .. _perf_cap: 86 .. _perf_cap:
87 87
88 AMD CPPC Performance Capability 88 AMD CPPC Performance Capability
89 -------------------------------- 89 --------------------------------
90 90
91 Highest Performance (RO) 91 Highest Performance (RO)
92 ......................... 92 .........................
93 93
94 This is the absolute maximum performance an in 94 This is the absolute maximum performance an individual processor may reach,
95 assuming ideal conditions. This performance le 95 assuming ideal conditions. This performance level may not be sustainable
96 for long durations and may only be achievable 96 for long durations and may only be achievable if other platform components
97 are in a specific state; for example, it may r 97 are in a specific state; for example, it may require other processors to be in
98 an idle state. This would be equivalent to the 98 an idle state. This would be equivalent to the highest frequencies
99 supported by the processor. 99 supported by the processor.
100 100
101 Nominal (Guaranteed) Performance (RO) 101 Nominal (Guaranteed) Performance (RO)
102 ...................................... 102 ......................................
103 103
104 This is the maximum sustained performance leve 104 This is the maximum sustained performance level of the processor, assuming
105 ideal operating conditions. In the absence of 105 ideal operating conditions. In the absence of an external constraint (power,
106 thermal, etc.), this is the performance level 106 thermal, etc.), this is the performance level the processor is expected to
107 be able to maintain continuously. All cores/pr 107 be able to maintain continuously. All cores/processors are expected to be
108 able to sustain their nominal performance stat 108 able to sustain their nominal performance state simultaneously.
109 109
110 Lowest non-linear Performance (RO) 110 Lowest non-linear Performance (RO)
111 ................................... 111 ...................................
112 112
113 This is the lowest performance level at which 113 This is the lowest performance level at which nonlinear power savings are
114 achieved, for example, due to the combined eff 114 achieved, for example, due to the combined effects of voltage and frequency
115 scaling. Above this threshold, lower performan 115 scaling. Above this threshold, lower performance levels should be generally
116 more energy efficient than higher performance 116 more energy efficient than higher performance levels. This register
117 effectively conveys the most efficient perform 117 effectively conveys the most efficient performance level to ``amd-pstate``.
118 118
119 Lowest Performance (RO) 119 Lowest Performance (RO)
120 ........................ 120 ........................
121 121
122 This is the absolute lowest performance level 122 This is the absolute lowest performance level of the processor. Selecting a
123 performance level lower than the lowest nonlin 123 performance level lower than the lowest nonlinear performance level may
124 cause an efficiency penalty but should reduce 124 cause an efficiency penalty but should reduce the instantaneous power
125 consumption of the processor. 125 consumption of the processor.
126 126
127 AMD CPPC Performance Control 127 AMD CPPC Performance Control
128 ------------------------------ 128 ------------------------------
129 129
130 ``amd-pstate`` passes performance goals throug 130 ``amd-pstate`` passes performance goals through these registers. The
131 register drives the behavior of the desired pe 131 register drives the behavior of the desired performance target.
132 132
133 Minimum requested performance (RW) 133 Minimum requested performance (RW)
134 ................................... 134 ...................................
135 135
136 ``amd-pstate`` specifies the minimum allowed p 136 ``amd-pstate`` specifies the minimum allowed performance level.
137 137
138 Maximum requested performance (RW) 138 Maximum requested performance (RW)
139 ................................... 139 ...................................
140 140
141 ``amd-pstate`` specifies a limit the maximum p 141 ``amd-pstate`` specifies a limit the maximum performance that is expected
142 to be supplied by the hardware. 142 to be supplied by the hardware.
143 143
144 Desired performance target (RW) 144 Desired performance target (RW)
145 ................................... 145 ...................................
146 146
147 ``amd-pstate`` specifies a desired target in t 147 ``amd-pstate`` specifies a desired target in the CPPC performance scale as
148 a relative number. This can be expressed as pe 148 a relative number. This can be expressed as percentage of nominal
149 performance (infrastructure max). Below the no 149 performance (infrastructure max). Below the nominal sustained performance
150 level, desired performance expresses the avera 150 level, desired performance expresses the average performance level of the
151 processor subject to hardware. Above the nomin 151 processor subject to hardware. Above the nominal performance level,
152 the processor must provide at least nominal pe 152 the processor must provide at least nominal performance requested and go higher
153 if current operating conditions allow. 153 if current operating conditions allow.
154 154
155 Energy Performance Preference (EPP) (RW) 155 Energy Performance Preference (EPP) (RW)
156 ......................................... 156 .........................................
157 157
158 This attribute provides a hint to the hardware 158 This attribute provides a hint to the hardware if software wants to bias
159 toward performance (0x0) or energy efficiency 159 toward performance (0x0) or energy efficiency (0xff).
160 160
161 161
162 Key Governors Support 162 Key Governors Support
163 ======================= 163 =======================
164 164
165 ``amd-pstate`` can be used with all the (gener 165 ``amd-pstate`` can be used with all the (generic) scaling governors listed
166 by the ``scaling_available_governors`` policy 166 by the ``scaling_available_governors`` policy attribute in ``sysfs``. Then,
167 it is responsible for the configuration of pol 167 it is responsible for the configuration of policy objects corresponding to
168 CPUs and provides the ``CPUFreq`` core (and th 168 CPUs and provides the ``CPUFreq`` core (and the scaling governors attached
169 to the policy objects) with accurate informati 169 to the policy objects) with accurate information on the maximum and minimum
170 operating frequencies supported by the hardwar 170 operating frequencies supported by the hardware. Users can check the
171 ``scaling_cur_freq`` information comes from th 171 ``scaling_cur_freq`` information comes from the ``CPUFreq`` core.
172 172
173 ``amd-pstate`` mainly supports ``schedutil`` a 173 ``amd-pstate`` mainly supports ``schedutil`` and ``ondemand`` for dynamic
174 frequency control. It is to fine tune the proc 174 frequency control. It is to fine tune the processor configuration on
175 ``amd-pstate`` to the ``schedutil`` with CPU C 175 ``amd-pstate`` to the ``schedutil`` with CPU CFS scheduler. ``amd-pstate``
176 registers the adjust_perf callback to implemen 176 registers the adjust_perf callback to implement performance update behavior
177 similar to CPPC. It is initialized by ``sugov_ 177 similar to CPPC. It is initialized by ``sugov_start`` and then populates the
178 CPU's update_util_data pointer to assign ``sug 178 CPU's update_util_data pointer to assign ``sugov_update_single_perf`` as the
179 utilization update callback function in the CP 179 utilization update callback function in the CPU scheduler. The CPU scheduler
180 will call ``cpufreq_update_util`` and assigns 180 will call ``cpufreq_update_util`` and assigns the target performance according
181 to the ``struct sugov_cpu`` that the utilizati 181 to the ``struct sugov_cpu`` that the utilization update belongs to.
182 Then, ``amd-pstate`` updates the desired perfo 182 Then, ``amd-pstate`` updates the desired performance according to the CPU
183 scheduler assigned. 183 scheduler assigned.
184 184
185 .. _processor_support: 185 .. _processor_support:
186 186
187 Processor Support 187 Processor Support
188 ======================= 188 =======================
189 189
190 The ``amd-pstate`` initialization will fail if 190 The ``amd-pstate`` initialization will fail if the ``_CPC`` entry in the ACPI
191 SBIOS does not exist in the detected processor 191 SBIOS does not exist in the detected processor. It uses ``acpi_cpc_valid``
192 to check the existence of ``_CPC``. All Zen ba 192 to check the existence of ``_CPC``. All Zen based processors support the legacy
193 ACPI hardware P-States function, so when ``amd 193 ACPI hardware P-States function, so when ``amd-pstate`` fails initialization,
194 the kernel will fall back to initialize the `` 194 the kernel will fall back to initialize the ``acpi-cpufreq`` driver.
195 195
196 There are two types of hardware implementation 196 There are two types of hardware implementations for ``amd-pstate``: one is
197 `Full MSR Support <perf_cap_>`_ and another is 197 `Full MSR Support <perf_cap_>`_ and another is `Shared Memory Support
198 <perf_cap_>`_. It can use the :c:macro:`X86_FE 198 <perf_cap_>`_. It can use the :c:macro:`X86_FEATURE_CPPC` feature flag to
199 indicate the different types. (For details, re 199 indicate the different types. (For details, refer to the Processor Programming
200 Reference (PPR) for AMD Family 19h Model 51h, 200 Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors [3]_.)
201 ``amd-pstate`` is to register different ``stat 201 ``amd-pstate`` is to register different ``static_call`` instances for different
202 hardware implementations. 202 hardware implementations.
203 203
204 Currently, some of the Zen2 and Zen3 processor 204 Currently, some of the Zen2 and Zen3 processors support ``amd-pstate``. In the
205 future, it will be supported on more and more 205 future, it will be supported on more and more AMD processors.
206 206
207 Full MSR Support 207 Full MSR Support
208 ----------------- 208 -----------------
209 209
210 Some new Zen3 processors such as Cezanne provi 210 Some new Zen3 processors such as Cezanne provide the MSR registers directly
211 while the :c:macro:`X86_FEATURE_CPPC` CPU feat 211 while the :c:macro:`X86_FEATURE_CPPC` CPU feature flag is set.
212 ``amd-pstate`` can handle the MSR register to 212 ``amd-pstate`` can handle the MSR register to implement the fast switch
213 function in ``CPUFreq`` that can reduce the la 213 function in ``CPUFreq`` that can reduce the latency of frequency control in
214 interrupt context. The functions with a ``psta 214 interrupt context. The functions with a ``pstate_xxx`` prefix represent the
215 operations on MSR registers. 215 operations on MSR registers.
216 216
217 Shared Memory Support 217 Shared Memory Support
218 ---------------------- 218 ----------------------
219 219
220 If the :c:macro:`X86_FEATURE_CPPC` CPU feature 220 If the :c:macro:`X86_FEATURE_CPPC` CPU feature flag is not set, the
221 processor supports the shared memory solution. 221 processor supports the shared memory solution. In this case, ``amd-pstate``
222 uses the ``cppc_acpi`` helper methods to imple 222 uses the ``cppc_acpi`` helper methods to implement the callback functions
223 that are defined on ``static_call``. The funct 223 that are defined on ``static_call``. The functions with the ``cppc_xxx`` prefix
224 represent the operations of ACPI CPPC helpers 224 represent the operations of ACPI CPPC helpers for the shared memory solution.
225 225
226 226
227 AMD P-States and ACPI hardware P-States always 227 AMD P-States and ACPI hardware P-States always can be supported in one
228 processor. But AMD P-States has the higher pri 228 processor. But AMD P-States has the higher priority and if it is enabled
229 with :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_ 229 with :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_set_enable``, it will respond
230 to the request from AMD P-States. 230 to the request from AMD P-States.
231 231
232 232
233 User Space Interface in ``sysfs`` - Per-policy 233 User Space Interface in ``sysfs`` - Per-policy control
234 ============================================== 234 ======================================================
235 235
236 ``amd-pstate`` exposes several global attribut 236 ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to
237 control its functionality at the system level. 237 control its functionality at the system level. They are located in the
238 ``/sys/devices/system/cpu/cpufreq/policyX/`` d 238 ``/sys/devices/system/cpu/cpufreq/policyX/`` directory and affect all CPUs. ::
239 239
240 root@hr-test1:/home/ray# ls /sys/devices/syst 240 root@hr-test1:/home/ray# ls /sys/devices/system/cpu/cpufreq/policy0/*amd*
241 /sys/devices/system/cpu/cpufreq/policy0/amd_p 241 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_highest_perf
242 /sys/devices/system/cpu/cpufreq/policy0/amd_p 242 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_lowest_nonlinear_freq
243 /sys/devices/system/cpu/cpufreq/policy0/amd_p 243 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_max_freq
244 244
245 245
246 ``amd_pstate_highest_perf / amd_pstate_max_fre 246 ``amd_pstate_highest_perf / amd_pstate_max_freq``
247 247
248 Maximum CPPC performance and CPU frequency tha 248 Maximum CPPC performance and CPU frequency that the driver is allowed to
249 set, in percent of the maximum supported CPPC 249 set, in percent of the maximum supported CPPC performance level (the highest
250 performance supported in `AMD CPPC Performance 250 performance supported in `AMD CPPC Performance Capability <perf_cap_>`_).
251 In some ASICs, the highest CPPC performance is 251 In some ASICs, the highest CPPC performance is not the one in the ``_CPC``
252 table, so we need to expose it to sysfs. If bo 252 table, so we need to expose it to sysfs. If boost is not active, but
253 still supported, this maximum frequency will b 253 still supported, this maximum frequency will be larger than the one in
254 ``cpuinfo``. On systems that support preferred !! 254 ``cpuinfo``.
255 different values for some cores than others an <<
256 advertised by the platform at bootup. <<
257 This attribute is read-only. 255 This attribute is read-only.
258 256
259 ``amd_pstate_lowest_nonlinear_freq`` 257 ``amd_pstate_lowest_nonlinear_freq``
260 258
261 The lowest non-linear CPPC CPU frequency that 259 The lowest non-linear CPPC CPU frequency that the driver is allowed to set,
262 in percent of the maximum supported CPPC perfo 260 in percent of the maximum supported CPPC performance level. (Please see the
263 lowest non-linear performance in `AMD CPPC Per 261 lowest non-linear performance in `AMD CPPC Performance Capability
264 <perf_cap_>`_.) 262 <perf_cap_>`_.)
265 This attribute is read-only. 263 This attribute is read-only.
266 <<
267 ``amd_pstate_hw_prefcore`` <<
268 <<
269 Whether the platform supports the preferred co <<
270 enabled. This attribute is read-only. <<
271 <<
272 ``amd_pstate_prefcore_ranking`` <<
273 <<
274 The performance ranking of the core. This numb <<
275 larger numbers are preferred at the time of re <<
276 runtime based on platform conditions. This att <<
277 264
278 ``energy_performance_available_preferences`` 265 ``energy_performance_available_preferences``
279 266
280 A list of all the supported EPP preferences th 267 A list of all the supported EPP preferences that could be used for
281 ``energy_performance_preference`` on this syst 268 ``energy_performance_preference`` on this system.
282 These profiles represent different hints that 269 These profiles represent different hints that are provided
283 to the low-level firmware about the user's des 270 to the low-level firmware about the user's desired energy vs efficiency
284 tradeoff. ``default`` represents the epp valu 271 tradeoff. ``default`` represents the epp value is set by platform
285 firmware. This attribute is read-only. 272 firmware. This attribute is read-only.
286 273
287 ``energy_performance_preference`` 274 ``energy_performance_preference``
288 275
289 The current energy performance preference can 276 The current energy performance preference can be read from this attribute.
290 and user can change current preference accordi 277 and user can change current preference according to energy or performance needs
291 Please get all support profiles list from 278 Please get all support profiles list from
292 ``energy_performance_available_preferences`` a 279 ``energy_performance_available_preferences`` attribute, all the profiles are
293 integer values defined between 0 to 255 when E 280 integer values defined between 0 to 255 when EPP feature is enabled by platform
294 firmware, if EPP feature is disabled, driver w 281 firmware, if EPP feature is disabled, driver will ignore the written value
295 This attribute is read-write. 282 This attribute is read-write.
296 283
297 ``boost`` 284 ``boost``
298 The `boost` sysfs attribute provides control o 285 The `boost` sysfs attribute provides control over the CPU core
299 performance boost, allowing users to manage th 286 performance boost, allowing users to manage the maximum frequency limitation
300 of the CPU. This attribute can be used to enab 287 of the CPU. This attribute can be used to enable or disable the boost feature
301 on individual CPUs. 288 on individual CPUs.
302 289
303 When the boost feature is enabled, the CPU can 290 When the boost feature is enabled, the CPU can dynamically increase its frequency
304 beyond the base frequency, providing enhanced 291 beyond the base frequency, providing enhanced performance for demanding workloads.
305 On the other hand, disabling the boost feature 292 On the other hand, disabling the boost feature restricts the CPU to operate at the
306 base frequency, which may be desirable in cert 293 base frequency, which may be desirable in certain scenarios to prioritize power
307 efficiency or manage temperature. 294 efficiency or manage temperature.
308 295
309 To manipulate the `boost` attribute, users can 296 To manipulate the `boost` attribute, users can write a value of `0` to disable the
310 boost or `1` to enable it, for the respective 297 boost or `1` to enable it, for the respective CPU using the sysfs path
311 `/sys/devices/system/cpu/cpuX/cpufreq/boost`, 298 `/sys/devices/system/cpu/cpuX/cpufreq/boost`, where `X` represents the CPU number.
312 299
313 Other performance and frequency values can be 300 Other performance and frequency values can be read back from
314 ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, s 301 ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.
315 302
316 303
317 ``amd-pstate`` vs ``acpi-cpufreq`` 304 ``amd-pstate`` vs ``acpi-cpufreq``
318 ====================================== 305 ======================================
319 306
320 On the majority of AMD platforms supported by 307 On the majority of AMD platforms supported by ``acpi-cpufreq``, the ACPI tables
321 provided by the platform firmware are used for 308 provided by the platform firmware are used for CPU performance scaling, but
322 only provide 3 P-states on AMD processors. 309 only provide 3 P-states on AMD processors.
323 However, on modern AMD APU and CPU series, har 310 However, on modern AMD APU and CPU series, hardware provides the Collaborative
324 Processor Performance Control according to the 311 Processor Performance Control according to the ACPI protocol and customizes this
325 for AMD platforms. That is, fine-grained and c 312 for AMD platforms. That is, fine-grained and continuous frequency ranges
326 instead of the legacy hardware P-states. ``amd 313 instead of the legacy hardware P-states. ``amd-pstate`` is the kernel
327 module which supports the new AMD P-States mec 314 module which supports the new AMD P-States mechanism on most of the future AMD
328 platforms. The AMD P-States mechanism is the m 315 platforms. The AMD P-States mechanism is the more performance and energy
329 efficiency frequency management method on AMD 316 efficiency frequency management method on AMD processors.
330 317
331 318
332 ``amd-pstate`` Driver Operation Modes 319 ``amd-pstate`` Driver Operation Modes
333 ====================================== 320 ======================================
334 321
335 ``amd_pstate`` CPPC has 3 operation modes: aut 322 ``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode,
336 non-autonomous (passive) mode and guided auton 323 non-autonomous (passive) mode and guided autonomous (guided) mode.
337 Active/passive/guided mode can be chosen by di 324 Active/passive/guided mode can be chosen by different kernel parameters.
338 325
339 - In autonomous mode, platform ignores the des 326 - In autonomous mode, platform ignores the desired performance level request
340 and takes into account only the values set t 327 and takes into account only the values set to the minimum, maximum and energy
341 performance preference registers. 328 performance preference registers.
342 - In non-autonomous mode, platform gets desire 329 - In non-autonomous mode, platform gets desired performance level
343 from OS directly through Desired Performance 330 from OS directly through Desired Performance Register.
344 - In guided-autonomous mode, platform sets ope 331 - In guided-autonomous mode, platform sets operating performance level
345 autonomously according to the current worklo 332 autonomously according to the current workload and within the limits set by
346 OS through min and max performance registers 333 OS through min and max performance registers.
347 334
348 Active Mode 335 Active Mode
349 ------------ 336 ------------
350 337
351 ``amd_pstate=active`` 338 ``amd_pstate=active``
352 339
353 This is the low-level firmware control mode wh 340 This is the low-level firmware control mode which is implemented by ``amd_pstate_epp``
354 driver with ``amd_pstate=active`` passed to th 341 driver with ``amd_pstate=active`` passed to the kernel in the command line.
355 In this mode, ``amd_pstate_epp`` driver provid 342 In this mode, ``amd_pstate_epp`` driver provides a hint to the hardware if software
356 wants to bias toward performance (0x0) or ener 343 wants to bias toward performance (0x0) or energy efficiency (0xff) to the CPPC firmware.
357 then CPPC power algorithm will calculate the r 344 then CPPC power algorithm will calculate the runtime workload and adjust the realtime
358 cores frequency according to the power supply 345 cores frequency according to the power supply and thermal, core voltage and some other
359 hardware conditions. 346 hardware conditions.
360 347
361 Passive Mode 348 Passive Mode
362 ------------ 349 ------------
363 350
364 ``amd_pstate=passive`` 351 ``amd_pstate=passive``
365 352
366 It will be enabled if the ``amd_pstate=passive 353 It will be enabled if the ``amd_pstate=passive`` is passed to the kernel in the command line.
367 In this mode, ``amd_pstate`` driver software s 354 In this mode, ``amd_pstate`` driver software specifies a desired QoS target in the CPPC
368 performance scale as a relative number. This c 355 performance scale as a relative number. This can be expressed as percentage of nominal
369 performance (infrastructure max). Below the no 356 performance (infrastructure max). Below the nominal sustained performance level,
370 desired performance expresses the average perf 357 desired performance expresses the average performance level of the processor subject
371 to the Performance Reduction Tolerance registe 358 to the Performance Reduction Tolerance register. Above the nominal performance level,
372 processor must provide at least nominal perfor 359 processor must provide at least nominal performance requested and go higher if current
373 operating conditions allow. 360 operating conditions allow.
374 361
375 Guided Mode 362 Guided Mode
376 ----------- 363 -----------
377 364
378 ``amd_pstate=guided`` 365 ``amd_pstate=guided``
379 366
380 If ``amd_pstate=guided`` is passed to kernel c 367 If ``amd_pstate=guided`` is passed to kernel command line option then this mode
381 is activated. In this mode, driver requests m 368 is activated. In this mode, driver requests minimum and maximum performance
382 level and the platform autonomously selects a 369 level and the platform autonomously selects a performance level in this range
383 and appropriate to the current workload. 370 and appropriate to the current workload.
384 371
385 ``amd-pstate`` Preferred Core 372 ``amd-pstate`` Preferred Core
386 ================================= 373 =================================
387 374
388 The core frequency is subjected to the process 375 The core frequency is subjected to the process variation in semiconductors.
389 Not all cores are able to reach the maximum fr 376 Not all cores are able to reach the maximum frequency respecting the
390 infrastructure limits. Consequently, AMD has r 377 infrastructure limits. Consequently, AMD has redefined the concept of
391 maximum frequency of a part. This means that a 378 maximum frequency of a part. This means that a fraction of cores can reach
392 maximum frequency. To find the best process sc 379 maximum frequency. To find the best process scheduling policy for a given
393 scenario, OS needs to know the core ordering i 380 scenario, OS needs to know the core ordering informed by the platform through
394 highest performance capability register of the 381 highest performance capability register of the CPPC interface.
395 382
396 ``amd-pstate`` preferred core enables the sche 383 ``amd-pstate`` preferred core enables the scheduler to prefer scheduling on
397 cores that can achieve a higher frequency with 384 cores that can achieve a higher frequency with lower voltage. The preferred
398 core rankings can dynamically change based on 385 core rankings can dynamically change based on the workload, platform conditions,
399 thermals and ageing. 386 thermals and ageing.
400 387
401 The priority metric will be initialized by the 388 The priority metric will be initialized by the ``amd-pstate`` driver. The ``amd-pstate``
402 driver will also determine whether or not ``am 389 driver will also determine whether or not ``amd-pstate`` preferred core is
403 supported by the platform. 390 supported by the platform.
404 391
405 ``amd-pstate`` driver will provide an initial 392 ``amd-pstate`` driver will provide an initial core ordering when the system boots.
406 The platform uses the CPPC interfaces to commu 393 The platform uses the CPPC interfaces to communicate the core ranking to the
407 operating system and scheduler to make sure th 394 operating system and scheduler to make sure that OS is choosing the cores
408 with highest performance firstly for schedulin 395 with highest performance firstly for scheduling the process. When ``amd-pstate``
409 driver receives a message with the highest per 396 driver receives a message with the highest performance change, it will
410 update the core ranking and set the cpu's prio 397 update the core ranking and set the cpu's priority.
411 398
412 ``amd-pstate`` Preferred Core Switch 399 ``amd-pstate`` Preferred Core Switch
413 ===================================== 400 =====================================
414 Kernel Parameters 401 Kernel Parameters
415 ----------------- 402 -----------------
416 403
417 ``amd-pstate`` peferred core`` has two states: 404 ``amd-pstate`` peferred core`` has two states: enable and disable.
418 Enable/disable states can be chosen by differe 405 Enable/disable states can be chosen by different kernel parameters.
419 Default enable ``amd-pstate`` preferred core. 406 Default enable ``amd-pstate`` preferred core.
420 407
421 ``amd_prefcore=disable`` 408 ``amd_prefcore=disable``
422 409
423 For systems that support ``amd-pstate`` prefer 410 For systems that support ``amd-pstate`` preferred core, the core rankings will
424 always be advertised by the platform. But OS c 411 always be advertised by the platform. But OS can choose to ignore that via the
425 kernel parameter ``amd_prefcore=disable``. 412 kernel parameter ``amd_prefcore=disable``.
426 413
427 User Space Interface in ``sysfs`` - General 414 User Space Interface in ``sysfs`` - General
428 =========================================== 415 ===========================================
429 416
430 Global Attributes 417 Global Attributes
431 ----------------- 418 -----------------
432 419
433 ``amd-pstate`` exposes several global attribut 420 ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to
434 control its functionality at the system level. 421 control its functionality at the system level. They are located in the
435 ``/sys/devices/system/cpu/amd_pstate/`` direct 422 ``/sys/devices/system/cpu/amd_pstate/`` directory and affect all CPUs.
436 423
437 ``status`` 424 ``status``
438 Operation mode of the driver: "active" 425 Operation mode of the driver: "active", "passive", "guided" or "disable".
439 426
440 "active" 427 "active"
441 The driver is functional and i 428 The driver is functional and in the ``active mode``
442 429
443 "passive" 430 "passive"
444 The driver is functional and i 431 The driver is functional and in the ``passive mode``
445 432
446 "guided" 433 "guided"
447 The driver is functional and i 434 The driver is functional and in the ``guided mode``
448 435
449 "disable" 436 "disable"
450 The driver is unregistered and 437 The driver is unregistered and not functional now.
451 438
452 This attribute can be written to in or 439 This attribute can be written to in order to change the driver's
453 operation mode or to unregister it. T 440 operation mode or to unregister it. The string written to it must be
454 one of the possible values of it and, 441 one of the possible values of it and, if successful, writing one of
455 these values to the sysfs file will ca 442 these values to the sysfs file will cause the driver to switch over
456 to the operation mode represented by t 443 to the operation mode represented by that string - or to be
457 unregistered in the "disable" case. 444 unregistered in the "disable" case.
458 445
459 ``prefcore`` 446 ``prefcore``
460 Preferred core state of the driver: "e 447 Preferred core state of the driver: "enabled" or "disabled".
461 448
462 "enabled" 449 "enabled"
463 Enable the ``amd-pstate`` pref 450 Enable the ``amd-pstate`` preferred core.
464 451
465 "disabled" 452 "disabled"
466 Disable the ``amd-pstate`` pre 453 Disable the ``amd-pstate`` preferred core
467 454
468 455
469 This attribute is read-only to check t 456 This attribute is read-only to check the state of preferred core set
470 by the kernel parameter. 457 by the kernel parameter.
471 458
472 ``cpupower`` tool support for ``amd-pstate`` 459 ``cpupower`` tool support for ``amd-pstate``
473 ============================================== 460 ===============================================
474 461
475 ``amd-pstate`` is supported by the ``cpupower` 462 ``amd-pstate`` is supported by the ``cpupower`` tool, which can be used to dump
476 frequency information. Development is in progr 463 frequency information. Development is in progress to support more and more
477 operations for the new ``amd-pstate`` module w 464 operations for the new ``amd-pstate`` module with this tool. ::
478 465
479 root@hr-test1:/home/ray# cpupower frequency-i 466 root@hr-test1:/home/ray# cpupower frequency-info
480 analyzing CPU 0: 467 analyzing CPU 0:
481 driver: amd-pstate 468 driver: amd-pstate
482 CPUs which run at the same hardware frequen 469 CPUs which run at the same hardware frequency: 0
483 CPUs which need to have their frequency coo 470 CPUs which need to have their frequency coordinated by software: 0
484 maximum transition latency: 131 us 471 maximum transition latency: 131 us
485 hardware limits: 400 MHz - 4.68 GHz 472 hardware limits: 400 MHz - 4.68 GHz
486 available cpufreq governors: ondemand conse 473 available cpufreq governors: ondemand conservative powersave userspace performance schedutil
487 current policy: frequency should be within 474 current policy: frequency should be within 400 MHz and 4.68 GHz.
488 The governor "schedutil" ma 475 The governor "schedutil" may decide which speed to use
489 within this range. 476 within this range.
490 current CPU frequency: Unable to call hardw 477 current CPU frequency: Unable to call hardware
491 current CPU frequency: 4.02 GHz (asserted b 478 current CPU frequency: 4.02 GHz (asserted by call to kernel)
492 boost state support: 479 boost state support:
493 Supported: yes 480 Supported: yes
494 Active: yes 481 Active: yes
495 AMD PSTATE Highest Performance: 166. Maxi 482 AMD PSTATE Highest Performance: 166. Maximum Frequency: 4.68 GHz.
496 AMD PSTATE Nominal Performance: 117. Nomi 483 AMD PSTATE Nominal Performance: 117. Nominal Frequency: 3.30 GHz.
497 AMD PSTATE Lowest Non-linear Performance: 484 AMD PSTATE Lowest Non-linear Performance: 39. Lowest Non-linear Frequency: 1.10 GHz.
498 AMD PSTATE Lowest Performance: 15. Lowest 485 AMD PSTATE Lowest Performance: 15. Lowest Frequency: 400 MHz.
499 486
500 487
501 Diagnostics and Tuning 488 Diagnostics and Tuning
502 ======================= 489 =======================
503 490
504 Trace Events 491 Trace Events
505 -------------- 492 --------------
506 493
507 There are two static trace events that can be 494 There are two static trace events that can be used for ``amd-pstate``
508 diagnostics. One of them is the ``cpu_frequenc 495 diagnostics. One of them is the ``cpu_frequency`` trace event generally used
509 by ``CPUFreq``, and the other one is the ``amd 496 by ``CPUFreq``, and the other one is the ``amd_pstate_perf`` trace event
510 specific to ``amd-pstate``. The following seq 497 specific to ``amd-pstate``. The following sequence of shell commands can
511 be used to enable them and see their output (i 498 be used to enable them and see their output (if the kernel is
512 configured to support event tracing). :: 499 configured to support event tracing). ::
513 500
514 root@hr-test1:/home/ray# cd /sys/kernel/traci 501 root@hr-test1:/home/ray# cd /sys/kernel/tracing/
515 root@hr-test1:/sys/kernel/tracing# echo 1 > e 502 root@hr-test1:/sys/kernel/tracing# echo 1 > events/amd_cpu/enable
516 root@hr-test1:/sys/kernel/tracing# cat trace 503 root@hr-test1:/sys/kernel/tracing# cat trace
517 # tracer: nop 504 # tracer: nop
518 # 505 #
519 # entries-in-buffer/entries-written: 47827/42 506 # entries-in-buffer/entries-written: 47827/42233061 #P:2
520 # 507 #
521 # _-----=> irq 508 # _-----=> irqs-off
522 # / _----=> nee 509 # / _----=> need-resched
523 # | / _---=> har 510 # | / _---=> hardirq/softirq
524 # || / _--=> pre 511 # || / _--=> preempt-depth
525 # ||| / dela 512 # ||| / delay
526 # TASK-PID CPU# |||| TIMESTA 513 # TASK-PID CPU# |||| TIMESTAMP FUNCTION
527 # | | | |||| | 514 # | | | |||| | |
528 <idle>-0 [015] dN... 4995.979 515 <idle>-0 [015] dN... 4995.979886: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=15 changed=false fast_switch=true
529 <idle>-0 [007] d.h.. 4995.979 516 <idle>-0 [007] d.h.. 4995.979893: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=7 changed=false fast_switch=true
530 cat-2161 [000] d.... 4995.980 517 cat-2161 [000] d.... 4995.980841: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=0 changed=false fast_switch=true
531 sshd-2125 [004] d.s.. 4995.980 518 sshd-2125 [004] d.s.. 4995.980968: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=4 changed=false fast_switch=true
532 <idle>-0 [007] d.s.. 4995.980 519 <idle>-0 [007] d.s.. 4995.980968: amd_pstate_perf: amd_min_perf=85 amd_des_perf=85 amd_max_perf=166 cpu_id=7 changed=false fast_switch=true
533 <idle>-0 [003] d.s.. 4995.980 520 <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
534 <idle>-0 [011] d.s.. 4995.980 521 <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
535 522
536 The ``cpu_frequency`` trace event will be trig 523 The ``cpu_frequency`` trace event will be triggered either by the ``schedutil`` scaling
537 governor (for the policies it is attached to), 524 governor (for the policies it is attached to), or by the ``CPUFreq`` core (for the
538 policies with other scaling governors). 525 policies with other scaling governors).
539 526
540 527
541 Tracer Tool 528 Tracer Tool
542 ------------- 529 -------------
543 530
544 ``amd_pstate_tracer.py`` can record and parse 531 ``amd_pstate_tracer.py`` can record and parse ``amd-pstate`` trace log, then
545 generate performance plots. This utility can b 532 generate performance plots. This utility can be used to debug and tune the
546 performance of ``amd-pstate`` driver. The trac 533 performance of ``amd-pstate`` driver. The tracer tool needs to import intel
547 pstate tracer. 534 pstate tracer.
548 535
549 Tracer tool located in ``linux/tools/power/x86 536 Tracer tool located in ``linux/tools/power/x86/amd_pstate_tracer``. It can be
550 used in two ways. If trace file is available, 537 used in two ways. If trace file is available, then directly parse the file
551 with command :: 538 with command ::
552 539
553 ./amd_pstate_trace.py [-c cpus] -t <trace_fil 540 ./amd_pstate_trace.py [-c cpus] -t <trace_file> -n <test_name>
554 541
555 Or generate trace file with root privilege, th 542 Or generate trace file with root privilege, then parse and plot with command ::
556 543
557 sudo ./amd_pstate_trace.py [-c cpus] -n <test 544 sudo ./amd_pstate_trace.py [-c cpus] -n <test_name> -i <interval> [-m kbytes]
558 545
559 The test result can be found in ``results/test 546 The test result can be found in ``results/test_name``. Following is the example
560 about part of the output. :: 547 about part of the output. ::
561 548
562 common_cpu common_secs common_usecs min_pe 549 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
563 CPU_005 712 116384 39 550 CPU_005 712 116384 39 49 166 0.7565 9645075 2214891 38431470 25.1 11.646 469 2.496 kworker/5:0-40
564 CPU_006 712 116408 39 551 CPU_006 712 116408 39 49 166 0.6769 8950227 1839034 37192089 24.06 11.272 470 2.496 kworker/6:0-1264
565 552
566 Unit Tests for amd-pstate 553 Unit Tests for amd-pstate
567 ------------------------- 554 -------------------------
568 555
569 ``amd-pstate-ut`` is a test module for testing 556 ``amd-pstate-ut`` is a test module for testing the ``amd-pstate`` driver.
570 557
571 * It can help all users to verify their proce 558 * It can help all users to verify their processor support (SBIOS/Firmware or Hardware).
572 559
573 * Kernel can have a basic function test to av 560 * Kernel can have a basic function test to avoid the kernel regression during the update.
574 561
575 * We can introduce more functional or perform 562 * We can introduce more functional or performance tests to align the result together, it will benefit power and performance scale optimization.
576 563
577 1. Test case descriptions 564 1. Test case descriptions
578 565
579 1). Basic tests 566 1). Basic tests
580 567
581 Test prerequisite and basic functions 568 Test prerequisite and basic functions for the ``amd-pstate`` driver.
582 569
583 +---------+--------------------------- 570 +---------+--------------------------------+------------------------------------------------------------------------------------+
584 | Index | Functions 571 | Index | Functions | Description |
585 +=========+=========================== 572 +=========+================================+====================================================================================+
586 | 1 | amd_pstate_ut_acpi_cpc_val 573 | 1 | amd_pstate_ut_acpi_cpc_valid || Check whether the _CPC object is present in SBIOS. |
587 | | 574 | | || |
588 | | 575 | | || The detail refer to `Processor Support <processor_support_>`_. |
589 +---------+--------------------------- 576 +---------+--------------------------------+------------------------------------------------------------------------------------+
590 | 2 | amd_pstate_ut_check_enable 577 | 2 | amd_pstate_ut_check_enabled || Check whether AMD P-State is enabled. |
591 | | 578 | | || |
592 | | 579 | | || AMD P-States and ACPI hardware P-States always can be supported in one processor. |
593 | | 580 | | | But AMD P-States has the higher priority and if it is enabled with |
594 | | 581 | | | :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_set_enable``, it will respond to the |
595 | | 582 | | | request from AMD P-States. |
596 +---------+--------------------------- 583 +---------+--------------------------------+------------------------------------------------------------------------------------+
597 | 3 | amd_pstate_ut_check_perf 584 | 3 | amd_pstate_ut_check_perf || Check if the each performance values are reasonable. |
598 | | 585 | | || highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0. |
599 +---------+--------------------------- 586 +---------+--------------------------------+------------------------------------------------------------------------------------+
600 | 4 | amd_pstate_ut_check_freq 587 | 4 | amd_pstate_ut_check_freq || Check if the each frequency values and max freq when set support boost mode |
601 | | 588 | | | are reasonable. |
602 | | 589 | | || max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0 |
603 | | 590 | | || If boost is not active but supported, this maximum frequency will be larger than |
604 | | 591 | | | the one in ``cpuinfo``. |
605 +---------+--------------------------- 592 +---------+--------------------------------+------------------------------------------------------------------------------------+
606 593
607 2). Tbench test 594 2). Tbench test
608 595
609 Test and monitor the cpu changes when 596 Test and monitor the cpu changes when running tbench benchmark under the specified governor.
610 These changes include desire performan 597 These changes include desire performance, frequency, load, performance, energy etc.
611 The specified governor is ondemand or 598 The specified governor is ondemand or schedutil.
612 Tbench can also be tested on the ``acp 599 Tbench can also be tested on the ``acpi-cpufreq`` kernel driver for comparison.
613 600
614 3). Gitsource test 601 3). Gitsource test
615 602
616 Test and monitor the cpu changes when 603 Test and monitor the cpu changes when running gitsource benchmark under the specified governor.
617 These changes include desire performan 604 These changes include desire performance, frequency, load, time, energy etc.
618 The specified governor is ondemand or 605 The specified governor is ondemand or schedutil.
619 Gitsource can also be tested on the `` 606 Gitsource can also be tested on the ``acpi-cpufreq`` kernel driver for comparison.
620 607
621 #. How to execute the tests 608 #. How to execute the tests
622 609
623 We use test module in the kselftest framewo 610 We use test module in the kselftest frameworks to implement it.
624 We create ``amd-pstate-ut`` module and tie 611 We create ``amd-pstate-ut`` module and tie it into kselftest.(for
625 details refer to Linux Kernel Selftests [4] 612 details refer to Linux Kernel Selftests [4]_).
626 613
627 1). Build 614 1). Build
628 615
629 + open the :c:macro:`CONFIG_X86_AMD_PS 616 + open the :c:macro:`CONFIG_X86_AMD_PSTATE` configuration option.
630 + set the :c:macro:`CONFIG_X86_AMD_PST 617 + set the :c:macro:`CONFIG_X86_AMD_PSTATE_UT` configuration option to M.
631 + make project 618 + make project
632 + make selftest :: 619 + make selftest ::
633 620
634 $ cd linux 621 $ cd linux
635 $ make -C tools/testing/selftests 622 $ make -C tools/testing/selftests
636 623
637 + make perf :: 624 + make perf ::
638 625
639 $ cd tools/perf/ 626 $ cd tools/perf/
640 $ make 627 $ make
641 628
642 629
643 2). Installation & Steps :: 630 2). Installation & Steps ::
644 631
645 $ make -C tools/testing/selftests inst 632 $ make -C tools/testing/selftests install INSTALL_PATH=~/kselftest
646 $ cp tools/perf/perf /usr/bin/perf 633 $ cp tools/perf/perf /usr/bin/perf
647 $ sudo ./kselftest/run_kselftest.sh -c 634 $ sudo ./kselftest/run_kselftest.sh -c amd-pstate
648 635
649 3). Specified test case :: 636 3). Specified test case ::
650 637
651 $ cd ~/kselftest/amd-pstate 638 $ cd ~/kselftest/amd-pstate
652 $ sudo ./run.sh -t basic 639 $ sudo ./run.sh -t basic
653 $ sudo ./run.sh -t tbench 640 $ sudo ./run.sh -t tbench
654 $ sudo ./run.sh -t tbench -m acpi-cpuf 641 $ sudo ./run.sh -t tbench -m acpi-cpufreq
655 $ sudo ./run.sh -t gitsource 642 $ sudo ./run.sh -t gitsource
656 $ sudo ./run.sh -t gitsource -m acpi-c 643 $ sudo ./run.sh -t gitsource -m acpi-cpufreq
657 $ ./run.sh --help 644 $ ./run.sh --help
658 ./run.sh: illegal option -- - 645 ./run.sh: illegal option -- -
659 Usage: ./run.sh [OPTION...] 646 Usage: ./run.sh [OPTION...]
660 [-h <help>] 647 [-h <help>]
661 [-o <output-file-for-dump>] 648 [-o <output-file-for-dump>]
662 [-c <all: All testing, 649 [-c <all: All testing,
663 basic: Basic testing, 650 basic: Basic testing,
664 tbench: Tbench testing, 651 tbench: Tbench testing,
665 gitsource: Gitsource test 652 gitsource: Gitsource testing.>]
666 [-t <tbench time limit>] 653 [-t <tbench time limit>]
667 [-p <tbench process number>] 654 [-p <tbench process number>]
668 [-l <loop times for tbench>] 655 [-l <loop times for tbench>]
669 [-i <amd tracer interval>] 656 [-i <amd tracer interval>]
670 [-m <comparative test: acpi-cp 657 [-m <comparative test: acpi-cpufreq>]
671 658
672 659
673 4). Results 660 4). Results
674 661
675 + basic 662 + basic
676 663
677 When you finish test, you will get th 664 When you finish test, you will get the following log info ::
678 665
679 $ dmesg | grep "amd_pstate_ut" | tee 666 $ dmesg | grep "amd_pstate_ut" | tee log.txt
680 [12977.570663] amd_pstate_ut: 1 a 667 [12977.570663] amd_pstate_ut: 1 amd_pstate_ut_acpi_cpc_valid success!
681 [12977.570673] amd_pstate_ut: 2 a 668 [12977.570673] amd_pstate_ut: 2 amd_pstate_ut_check_enabled success!
682 [12977.571207] amd_pstate_ut: 3 a 669 [12977.571207] amd_pstate_ut: 3 amd_pstate_ut_check_perf success!
683 [12977.571212] amd_pstate_ut: 4 a 670 [12977.571212] amd_pstate_ut: 4 amd_pstate_ut_check_freq success!
684 671
685 + tbench 672 + tbench
686 673
687 When you finish test, you will get se 674 When you finish test, you will get selftest.tbench.csv and png images.
688 The selftest.tbench.csv file contains 675 The selftest.tbench.csv file contains the raw data and the drop of the comparative test.
689 The png images shows the performance, 676 The png images shows the performance, energy and performan per watt of each test.
690 Open selftest.tbench.csv : 677 Open selftest.tbench.csv :
691 678
692 +------------------------------------ 679 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
693 + Governor 680 + Governor | Round | Des-perf | Freq | Load | Performance | Energy | Performance Per Watt |
694 +------------------------------------ 681 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
695 + Unit 682 + Unit | | | GHz | | MB/s | J | MB/J |
696 +==================================== 683 +=================================================+==============+==========+=========+==========+=============+=========+======================+
697 + amd-pstate-ondemand 684 + amd-pstate-ondemand | 1 | | | | 2504.05 | 1563.67 | 158.5378 |
698 +------------------------------------ 685 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
699 + amd-pstate-ondemand 686 + amd-pstate-ondemand | 2 | | | | 2243.64 | 1430.32 | 155.2941 |
700 +------------------------------------ 687 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
701 + amd-pstate-ondemand 688 + amd-pstate-ondemand | 3 | | | | 2183.88 | 1401.32 | 154.2860 |
702 +------------------------------------ 689 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
703 + amd-pstate-ondemand 690 + amd-pstate-ondemand | Average | | | | 2310.52 | 1465.1 | 156.1268 |
704 +------------------------------------ 691 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
705 + amd-pstate-schedutil 692 + amd-pstate-schedutil | 1 | 165.329 | 1.62257 | 99.798 | 2136.54 | 1395.26 | 151.5971 |
706 +------------------------------------ 693 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
707 + amd-pstate-schedutil 694 + amd-pstate-schedutil | 2 | 166 | 1.49761 | 99.9993 | 2100.56 | 1380.5 | 150.6377 |
708 +------------------------------------ 695 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
709 + amd-pstate-schedutil 696 + amd-pstate-schedutil | 3 | 166 | 1.47806 | 99.9993 | 2084.12 | 1375.76 | 149.9737 |
710 +------------------------------------ 697 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
711 + amd-pstate-schedutil 698 + amd-pstate-schedutil | Average | 165.776 | 1.53275 | 99.9322 | 2107.07 | 1383.84 | 150.7399 |
712 +------------------------------------ 699 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
713 + acpi-cpufreq-ondemand 700 + acpi-cpufreq-ondemand | 1 | | | | 2529.9 | 1564.4 | 160.0997 |
714 +------------------------------------ 701 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
715 + acpi-cpufreq-ondemand 702 + acpi-cpufreq-ondemand | 2 | | | | 2249.76 | 1432.97 | 155.4297 |
716 +------------------------------------ 703 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
717 + acpi-cpufreq-ondemand 704 + acpi-cpufreq-ondemand | 3 | | | | 2181.46 | 1406.88 | 153.5060 |
718 +------------------------------------ 705 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
719 + acpi-cpufreq-ondemand 706 + acpi-cpufreq-ondemand | Average | | | | 2320.37 | 1468.08 | 156.4741 |
720 +------------------------------------ 707 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
721 + acpi-cpufreq-schedutil 708 + acpi-cpufreq-schedutil | 1 | | | | 2137.64 | 1385.24 | 152.7723 |
722 +------------------------------------ 709 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
723 + acpi-cpufreq-schedutil 710 + acpi-cpufreq-schedutil | 2 | | | | 2107.05 | 1372.23 | 152.0138 |
724 +------------------------------------ 711 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
725 + acpi-cpufreq-schedutil 712 + acpi-cpufreq-schedutil | 3 | | | | 2085.86 | 1365.35 | 151.2433 |
726 +------------------------------------ 713 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
727 + acpi-cpufreq-schedutil 714 + acpi-cpufreq-schedutil | Average | | | | 2110.18 | 1374.27 | 152.0136 |
728 +------------------------------------ 715 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
729 + acpi-cpufreq-ondemand VS acpi-cpufr 716 + acpi-cpufreq-ondemand VS acpi-cpufreq-schedutil | Comprison(%) | | | | -9.0584 | -6.3899 | -2.8506 |
730 +------------------------------------ 717 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
731 + amd-pstate-ondemand VS amd-pstate-s 718 + amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | | | | 8.8053 | -5.5463 | -3.4503 |
732 +------------------------------------ 719 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
733 + acpi-cpufreq-ondemand VS amd-pstate 720 + acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | | -0.4245 | -0.2029 | -0.2219 |
734 +------------------------------------ 721 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
735 + acpi-cpufreq-schedutil VS amd-pstat 722 + acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | | -0.1473 | 0.6963 | -0.8378 |
736 +------------------------------------ 723 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
737 724
738 + gitsource 725 + gitsource
739 726
740 When you finish test, you will get se 727 When you finish test, you will get selftest.gitsource.csv and png images.
741 The selftest.gitsource.csv file conta 728 The selftest.gitsource.csv file contains the raw data and the drop of the comparative test.
742 The png images shows the performance, 729 The png images shows the performance, energy and performan per watt of each test.
743 Open selftest.gitsource.csv : 730 Open selftest.gitsource.csv :
744 731
745 +------------------------------------ 732 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
746 + Governor 733 + Governor | Round | Des-perf | Freq | Load | Time | Energy | Performance Per Watt |
747 +------------------------------------ 734 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
748 + Unit 735 + Unit | | | GHz | | s | J | 1/J |
749 +==================================== 736 +=================================================+==============+==========+==========+==========+=============+=========+======================+
750 + amd-pstate-ondemand 737 + amd-pstate-ondemand | 1 | 50.119 | 2.10509 | 23.3076 | 475.69 | 865.78 | 0.001155027 |
751 +------------------------------------ 738 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
752 + amd-pstate-ondemand 739 + amd-pstate-ondemand | 2 | 94.8006 | 1.98771 | 56.6533 | 467.1 | 839.67 | 0.001190944 |
753 +------------------------------------ 740 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
754 + amd-pstate-ondemand 741 + amd-pstate-ondemand | 3 | 76.6091 | 2.53251 | 43.7791 | 467.69 | 855.85 | 0.001168429 |
755 +------------------------------------ 742 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
756 + amd-pstate-ondemand 743 + amd-pstate-ondemand | Average | 73.8429 | 2.20844 | 41.2467 | 470.16 | 853.767 | 0.001171279 |
757 +------------------------------------ 744 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
758 + amd-pstate-schedutil 745 + amd-pstate-schedutil | 1 | 165.919 | 1.62319 | 98.3868 | 464.17 | 866.8 | 0.001153668 |
759 +------------------------------------ 746 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
760 + amd-pstate-schedutil 747 + amd-pstate-schedutil | 2 | 165.97 | 1.31309 | 99.5712 | 480.15 | 880.4 | 0.001135847 |
761 +------------------------------------ 748 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
762 + amd-pstate-schedutil 749 + amd-pstate-schedutil | 3 | 165.973 | 1.28448 | 99.9252 | 481.79 | 867.02 | 0.001153375 |
763 +------------------------------------ 750 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
764 + amd-pstate-schedutil 751 + amd-pstate-schedutil | Average | 165.954 | 1.40692 | 99.2944 | 475.37 | 871.407 | 0.001147569 |
765 +------------------------------------ 752 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
766 + acpi-cpufreq-ondemand 753 + acpi-cpufreq-ondemand | 1 | | | | 2379.62 | 742.96 | 0.001345967 |
767 +------------------------------------ 754 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
768 + acpi-cpufreq-ondemand 755 + acpi-cpufreq-ondemand | 2 | | | | 441.74 | 817.49 | 0.001223256 |
769 +------------------------------------ 756 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
770 + acpi-cpufreq-ondemand 757 + acpi-cpufreq-ondemand | 3 | | | | 455.48 | 820.01 | 0.001219497 |
771 +------------------------------------ 758 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
772 + acpi-cpufreq-ondemand 759 + acpi-cpufreq-ondemand | Average | | | | 425.613 | 793.487 | 0.001260260 |
773 +------------------------------------ 760 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
774 + acpi-cpufreq-schedutil 761 + acpi-cpufreq-schedutil | 1 | | | | 459.69 | 838.54 | 0.001192548 |
775 +------------------------------------ 762 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
776 + acpi-cpufreq-schedutil 763 + acpi-cpufreq-schedutil | 2 | | | | 466.55 | 830.89 | 0.001203528 |
777 +------------------------------------ 764 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
778 + acpi-cpufreq-schedutil 765 + acpi-cpufreq-schedutil | 3 | | | | 470.38 | 837.32 | 0.001194286 |
779 +------------------------------------ 766 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
780 + acpi-cpufreq-schedutil 767 + acpi-cpufreq-schedutil | Average | | | | 465.54 | 835.583 | 0.001196769 |
781 +------------------------------------ 768 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
782 + acpi-cpufreq-ondemand VS acpi-cpufr 769 + acpi-cpufreq-ondemand VS acpi-cpufreq-schedutil | Comprison(%) | | | | 9.3810 | 5.3051 | -5.0379 |
783 +------------------------------------ 770 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
784 + amd-pstate-ondemand VS amd-pstate-s 771 + amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | 124.7392 | -36.2934 | 140.7329 | 1.1081 | 2.0661 | -2.0242 |
785 +------------------------------------ 772 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
786 + acpi-cpufreq-ondemand VS amd-pstate 773 + acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | | 10.4665 | 7.5968 | -7.0605 |
787 +------------------------------------ 774 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
788 + acpi-cpufreq-schedutil VS amd-pstat 775 + acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | | 2.1115 | 4.2873 | -4.1110 |
789 +------------------------------------ 776 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
790 777
791 Reference 778 Reference
792 =========== 779 ===========
793 780
794 .. [1] AMD64 Architecture Programmer's Manual 781 .. [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming,
795 https://www.amd.com/system/files/TechDo 782 https://www.amd.com/system/files/TechDocs/24593.pdf
796 783
797 .. [2] Advanced Configuration and Power Interf 784 .. [2] Advanced Configuration and Power Interface Specification,
798 https://uefi.org/sites/default/files/re 785 https://uefi.org/sites/default/files/resources/ACPI_Spec_6_4_Jan22.pdf
799 786
800 .. [3] Processor Programming Reference (PPR) f 787 .. [3] Processor Programming Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors
801 https://www.amd.com/system/files/TechDo 788 https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip
802 789
803 .. [4] Linux Kernel Selftests, 790 .. [4] Linux Kernel Selftests,
804 https://www.kernel.org/doc/html/latest/ 791 https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html
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