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.
266 264
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 <<
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`` <<
298 The `boost` sysfs attribute provides control o <<
299 performance boost, allowing users to manage th <<
300 of the CPU. This attribute can be used to enab <<
301 on individual CPUs. <<
302 <<
303 When the boost feature is enabled, the CPU can <<
304 beyond the base frequency, providing enhanced <<
305 On the other hand, disabling the boost feature <<
306 base frequency, which may be desirable in cert <<
307 efficiency or manage temperature. <<
308 <<
309 To manipulate the `boost` attribute, users can <<
310 boost or `1` to enable it, for the respective <<
311 `/sys/devices/system/cpu/cpuX/cpufreq/boost`, <<
312 <<
313 Other performance and frequency values can be 284 Other performance and frequency values can be read back from
314 ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, s 285 ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.
315 286
316 287
317 ``amd-pstate`` vs ``acpi-cpufreq`` 288 ``amd-pstate`` vs ``acpi-cpufreq``
318 ====================================== 289 ======================================
319 290
320 On the majority of AMD platforms supported by 291 On the majority of AMD platforms supported by ``acpi-cpufreq``, the ACPI tables
321 provided by the platform firmware are used for 292 provided by the platform firmware are used for CPU performance scaling, but
322 only provide 3 P-states on AMD processors. 293 only provide 3 P-states on AMD processors.
323 However, on modern AMD APU and CPU series, har 294 However, on modern AMD APU and CPU series, hardware provides the Collaborative
324 Processor Performance Control according to the 295 Processor Performance Control according to the ACPI protocol and customizes this
325 for AMD platforms. That is, fine-grained and c 296 for AMD platforms. That is, fine-grained and continuous frequency ranges
326 instead of the legacy hardware P-states. ``amd 297 instead of the legacy hardware P-states. ``amd-pstate`` is the kernel
327 module which supports the new AMD P-States mec 298 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 299 platforms. The AMD P-States mechanism is the more performance and energy
329 efficiency frequency management method on AMD 300 efficiency frequency management method on AMD processors.
330 301
331 302
332 ``amd-pstate`` Driver Operation Modes !! 303 AMD Pstate Driver Operation Modes
333 ====================================== !! 304 =================================
334 305
335 ``amd_pstate`` CPPC has 3 operation modes: aut 306 ``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode,
336 non-autonomous (passive) mode and guided auton 307 non-autonomous (passive) mode and guided autonomous (guided) mode.
337 Active/passive/guided mode can be chosen by di 308 Active/passive/guided mode can be chosen by different kernel parameters.
338 309
339 - In autonomous mode, platform ignores the des 310 - In autonomous mode, platform ignores the desired performance level request
340 and takes into account only the values set t 311 and takes into account only the values set to the minimum, maximum and energy
341 performance preference registers. 312 performance preference registers.
342 - In non-autonomous mode, platform gets desire 313 - In non-autonomous mode, platform gets desired performance level
343 from OS directly through Desired Performance 314 from OS directly through Desired Performance Register.
344 - In guided-autonomous mode, platform sets ope 315 - In guided-autonomous mode, platform sets operating performance level
345 autonomously according to the current worklo 316 autonomously according to the current workload and within the limits set by
346 OS through min and max performance registers 317 OS through min and max performance registers.
347 318
348 Active Mode 319 Active Mode
349 ------------ 320 ------------
350 321
351 ``amd_pstate=active`` 322 ``amd_pstate=active``
352 323
353 This is the low-level firmware control mode wh 324 This is the low-level firmware control mode which is implemented by ``amd_pstate_epp``
354 driver with ``amd_pstate=active`` passed to th 325 driver with ``amd_pstate=active`` passed to the kernel in the command line.
355 In this mode, ``amd_pstate_epp`` driver provid 326 In this mode, ``amd_pstate_epp`` driver provides a hint to the hardware if software
356 wants to bias toward performance (0x0) or ener 327 wants to bias toward performance (0x0) or energy efficiency (0xff) to the CPPC firmware.
357 then CPPC power algorithm will calculate the r 328 then CPPC power algorithm will calculate the runtime workload and adjust the realtime
358 cores frequency according to the power supply 329 cores frequency according to the power supply and thermal, core voltage and some other
359 hardware conditions. 330 hardware conditions.
360 331
361 Passive Mode 332 Passive Mode
362 ------------ 333 ------------
363 334
364 ``amd_pstate=passive`` 335 ``amd_pstate=passive``
365 336
366 It will be enabled if the ``amd_pstate=passive 337 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 338 In this mode, ``amd_pstate`` driver software specifies a desired QoS target in the CPPC
368 performance scale as a relative number. This c 339 performance scale as a relative number. This can be expressed as percentage of nominal
369 performance (infrastructure max). Below the no 340 performance (infrastructure max). Below the nominal sustained performance level,
370 desired performance expresses the average perf 341 desired performance expresses the average performance level of the processor subject
371 to the Performance Reduction Tolerance registe 342 to the Performance Reduction Tolerance register. Above the nominal performance level,
372 processor must provide at least nominal perfor 343 processor must provide at least nominal performance requested and go higher if current
373 operating conditions allow. 344 operating conditions allow.
374 345
375 Guided Mode 346 Guided Mode
376 ----------- 347 -----------
377 348
378 ``amd_pstate=guided`` 349 ``amd_pstate=guided``
379 350
380 If ``amd_pstate=guided`` is passed to kernel c 351 If ``amd_pstate=guided`` is passed to kernel command line option then this mode
381 is activated. In this mode, driver requests m 352 is activated. In this mode, driver requests minimum and maximum performance
382 level and the platform autonomously selects a 353 level and the platform autonomously selects a performance level in this range
383 and appropriate to the current workload. 354 and appropriate to the current workload.
384 355
385 ``amd-pstate`` Preferred Core <<
386 ================================= <<
387 <<
388 The core frequency is subjected to the process <<
389 Not all cores are able to reach the maximum fr <<
390 infrastructure limits. Consequently, AMD has r <<
391 maximum frequency of a part. This means that a <<
392 maximum frequency. To find the best process sc <<
393 scenario, OS needs to know the core ordering i <<
394 highest performance capability register of the <<
395 <<
396 ``amd-pstate`` preferred core enables the sche <<
397 cores that can achieve a higher frequency with <<
398 core rankings can dynamically change based on <<
399 thermals and ageing. <<
400 <<
401 The priority metric will be initialized by the <<
402 driver will also determine whether or not ``am <<
403 supported by the platform. <<
404 <<
405 ``amd-pstate`` driver will provide an initial <<
406 The platform uses the CPPC interfaces to commu <<
407 operating system and scheduler to make sure th <<
408 with highest performance firstly for schedulin <<
409 driver receives a message with the highest per <<
410 update the core ranking and set the cpu's prio <<
411 <<
412 ``amd-pstate`` Preferred Core Switch <<
413 ===================================== <<
414 Kernel Parameters <<
415 ----------------- <<
416 <<
417 ``amd-pstate`` peferred core`` has two states: <<
418 Enable/disable states can be chosen by differe <<
419 Default enable ``amd-pstate`` preferred core. <<
420 <<
421 ``amd_prefcore=disable`` <<
422 <<
423 For systems that support ``amd-pstate`` prefer <<
424 always be advertised by the platform. But OS c <<
425 kernel parameter ``amd_prefcore=disable``. <<
426 <<
427 User Space Interface in ``sysfs`` - General 356 User Space Interface in ``sysfs`` - General
428 =========================================== 357 ===========================================
429 358
430 Global Attributes 359 Global Attributes
431 ----------------- 360 -----------------
432 361
433 ``amd-pstate`` exposes several global attribut 362 ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to
434 control its functionality at the system level. 363 control its functionality at the system level. They are located in the
435 ``/sys/devices/system/cpu/amd_pstate/`` direct !! 364 ``/sys/devices/system/cpu/amd-pstate/`` directory and affect all CPUs.
436 365
437 ``status`` 366 ``status``
438 Operation mode of the driver: "active" !! 367 Operation mode of the driver: "active", "passive" or "disable".
439 368
440 "active" 369 "active"
441 The driver is functional and i 370 The driver is functional and in the ``active mode``
442 371
443 "passive" 372 "passive"
444 The driver is functional and i 373 The driver is functional and in the ``passive mode``
445 374
446 "guided" 375 "guided"
447 The driver is functional and i 376 The driver is functional and in the ``guided mode``
448 377
449 "disable" 378 "disable"
450 The driver is unregistered and 379 The driver is unregistered and not functional now.
451 380
452 This attribute can be written to in or 381 This attribute can be written to in order to change the driver's
453 operation mode or to unregister it. T 382 operation mode or to unregister it. The string written to it must be
454 one of the possible values of it and, 383 one of the possible values of it and, if successful, writing one of
455 these values to the sysfs file will ca 384 these values to the sysfs file will cause the driver to switch over
456 to the operation mode represented by t 385 to the operation mode represented by that string - or to be
457 unregistered in the "disable" case. 386 unregistered in the "disable" case.
458 <<
459 ``prefcore`` <<
460 Preferred core state of the driver: "e <<
461 <<
462 "enabled" <<
463 Enable the ``amd-pstate`` pref <<
464 <<
465 "disabled" <<
466 Disable the ``amd-pstate`` pre <<
467 <<
468 <<
469 This attribute is read-only to check t <<
470 by the kernel parameter. <<
471 387
472 ``cpupower`` tool support for ``amd-pstate`` 388 ``cpupower`` tool support for ``amd-pstate``
473 ============================================== 389 ===============================================
474 390
475 ``amd-pstate`` is supported by the ``cpupower` 391 ``amd-pstate`` is supported by the ``cpupower`` tool, which can be used to dump
476 frequency information. Development is in progr 392 frequency information. Development is in progress to support more and more
477 operations for the new ``amd-pstate`` module w 393 operations for the new ``amd-pstate`` module with this tool. ::
478 394
479 root@hr-test1:/home/ray# cpupower frequency-i 395 root@hr-test1:/home/ray# cpupower frequency-info
480 analyzing CPU 0: 396 analyzing CPU 0:
481 driver: amd-pstate 397 driver: amd-pstate
482 CPUs which run at the same hardware frequen 398 CPUs which run at the same hardware frequency: 0
483 CPUs which need to have their frequency coo 399 CPUs which need to have their frequency coordinated by software: 0
484 maximum transition latency: 131 us 400 maximum transition latency: 131 us
485 hardware limits: 400 MHz - 4.68 GHz 401 hardware limits: 400 MHz - 4.68 GHz
486 available cpufreq governors: ondemand conse 402 available cpufreq governors: ondemand conservative powersave userspace performance schedutil
487 current policy: frequency should be within 403 current policy: frequency should be within 400 MHz and 4.68 GHz.
488 The governor "schedutil" ma 404 The governor "schedutil" may decide which speed to use
489 within this range. 405 within this range.
490 current CPU frequency: Unable to call hardw 406 current CPU frequency: Unable to call hardware
491 current CPU frequency: 4.02 GHz (asserted b 407 current CPU frequency: 4.02 GHz (asserted by call to kernel)
492 boost state support: 408 boost state support:
493 Supported: yes 409 Supported: yes
494 Active: yes 410 Active: yes
495 AMD PSTATE Highest Performance: 166. Maxi 411 AMD PSTATE Highest Performance: 166. Maximum Frequency: 4.68 GHz.
496 AMD PSTATE Nominal Performance: 117. Nomi 412 AMD PSTATE Nominal Performance: 117. Nominal Frequency: 3.30 GHz.
497 AMD PSTATE Lowest Non-linear Performance: 413 AMD PSTATE Lowest Non-linear Performance: 39. Lowest Non-linear Frequency: 1.10 GHz.
498 AMD PSTATE Lowest Performance: 15. Lowest 414 AMD PSTATE Lowest Performance: 15. Lowest Frequency: 400 MHz.
499 415
500 416
501 Diagnostics and Tuning 417 Diagnostics and Tuning
502 ======================= 418 =======================
503 419
504 Trace Events 420 Trace Events
505 -------------- 421 --------------
506 422
507 There are two static trace events that can be 423 There are two static trace events that can be used for ``amd-pstate``
508 diagnostics. One of them is the ``cpu_frequenc 424 diagnostics. One of them is the ``cpu_frequency`` trace event generally used
509 by ``CPUFreq``, and the other one is the ``amd 425 by ``CPUFreq``, and the other one is the ``amd_pstate_perf`` trace event
510 specific to ``amd-pstate``. The following seq 426 specific to ``amd-pstate``. The following sequence of shell commands can
511 be used to enable them and see their output (i 427 be used to enable them and see their output (if the kernel is
512 configured to support event tracing). :: 428 configured to support event tracing). ::
513 429
514 root@hr-test1:/home/ray# cd /sys/kernel/traci 430 root@hr-test1:/home/ray# cd /sys/kernel/tracing/
515 root@hr-test1:/sys/kernel/tracing# echo 1 > e 431 root@hr-test1:/sys/kernel/tracing# echo 1 > events/amd_cpu/enable
516 root@hr-test1:/sys/kernel/tracing# cat trace 432 root@hr-test1:/sys/kernel/tracing# cat trace
517 # tracer: nop 433 # tracer: nop
518 # 434 #
519 # entries-in-buffer/entries-written: 47827/42 435 # entries-in-buffer/entries-written: 47827/42233061 #P:2
520 # 436 #
521 # _-----=> irq 437 # _-----=> irqs-off
522 # / _----=> nee 438 # / _----=> need-resched
523 # | / _---=> har 439 # | / _---=> hardirq/softirq
524 # || / _--=> pre 440 # || / _--=> preempt-depth
525 # ||| / dela 441 # ||| / delay
526 # TASK-PID CPU# |||| TIMESTA 442 # TASK-PID CPU# |||| TIMESTAMP FUNCTION
527 # | | | |||| | 443 # | | | |||| | |
528 <idle>-0 [015] dN... 4995.979 444 <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.. 4995.979 445 <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.... 4995.980 446 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.. 4995.980 447 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.. 4995.980 448 <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.. 4995.980 449 <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.. 4995.980 450 <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
535 451
536 The ``cpu_frequency`` trace event will be trig 452 The ``cpu_frequency`` trace event will be triggered either by the ``schedutil`` scaling
537 governor (for the policies it is attached to), 453 governor (for the policies it is attached to), or by the ``CPUFreq`` core (for the
538 policies with other scaling governors). 454 policies with other scaling governors).
539 455
540 456
541 Tracer Tool 457 Tracer Tool
542 ------------- 458 -------------
543 459
544 ``amd_pstate_tracer.py`` can record and parse 460 ``amd_pstate_tracer.py`` can record and parse ``amd-pstate`` trace log, then
545 generate performance plots. This utility can b 461 generate performance plots. This utility can be used to debug and tune the
546 performance of ``amd-pstate`` driver. The trac 462 performance of ``amd-pstate`` driver. The tracer tool needs to import intel
547 pstate tracer. 463 pstate tracer.
548 464
549 Tracer tool located in ``linux/tools/power/x86 465 Tracer tool located in ``linux/tools/power/x86/amd_pstate_tracer``. It can be
550 used in two ways. If trace file is available, 466 used in two ways. If trace file is available, then directly parse the file
551 with command :: 467 with command ::
552 468
553 ./amd_pstate_trace.py [-c cpus] -t <trace_fil 469 ./amd_pstate_trace.py [-c cpus] -t <trace_file> -n <test_name>
554 470
555 Or generate trace file with root privilege, th 471 Or generate trace file with root privilege, then parse and plot with command ::
556 472
557 sudo ./amd_pstate_trace.py [-c cpus] -n <test 473 sudo ./amd_pstate_trace.py [-c cpus] -n <test_name> -i <interval> [-m kbytes]
558 474
559 The test result can be found in ``results/test 475 The test result can be found in ``results/test_name``. Following is the example
560 about part of the output. :: 476 about part of the output. ::
561 477
562 common_cpu common_secs common_usecs min_pe 478 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 39 479 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 39 480 CPU_006 712 116408 39 49 166 0.6769 8950227 1839034 37192089 24.06 11.272 470 2.496 kworker/6:0-1264
565 481
566 Unit Tests for amd-pstate 482 Unit Tests for amd-pstate
567 ------------------------- 483 -------------------------
568 484
569 ``amd-pstate-ut`` is a test module for testing 485 ``amd-pstate-ut`` is a test module for testing the ``amd-pstate`` driver.
570 486
571 * It can help all users to verify their proce 487 * It can help all users to verify their processor support (SBIOS/Firmware or Hardware).
572 488
573 * Kernel can have a basic function test to av 489 * Kernel can have a basic function test to avoid the kernel regression during the update.
574 490
575 * We can introduce more functional or perform 491 * We can introduce more functional or performance tests to align the result together, it will benefit power and performance scale optimization.
576 492
577 1. Test case descriptions 493 1. Test case descriptions
578 494
579 1). Basic tests 495 1). Basic tests
580 496
581 Test prerequisite and basic functions 497 Test prerequisite and basic functions for the ``amd-pstate`` driver.
582 498
583 +---------+--------------------------- 499 +---------+--------------------------------+------------------------------------------------------------------------------------+
584 | Index | Functions 500 | Index | Functions | Description |
585 +=========+=========================== 501 +=========+================================+====================================================================================+
586 | 1 | amd_pstate_ut_acpi_cpc_val 502 | 1 | amd_pstate_ut_acpi_cpc_valid || Check whether the _CPC object is present in SBIOS. |
587 | | 503 | | || |
588 | | 504 | | || The detail refer to `Processor Support <processor_support_>`_. |
589 +---------+--------------------------- 505 +---------+--------------------------------+------------------------------------------------------------------------------------+
590 | 2 | amd_pstate_ut_check_enable 506 | 2 | amd_pstate_ut_check_enabled || Check whether AMD P-State is enabled. |
591 | | 507 | | || |
592 | | 508 | | || AMD P-States and ACPI hardware P-States always can be supported in one processor. |
593 | | 509 | | | But AMD P-States has the higher priority and if it is enabled with |
594 | | 510 | | | :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_set_enable``, it will respond to the |
595 | | 511 | | | request from AMD P-States. |
596 +---------+--------------------------- 512 +---------+--------------------------------+------------------------------------------------------------------------------------+
597 | 3 | amd_pstate_ut_check_perf 513 | 3 | amd_pstate_ut_check_perf || Check if the each performance values are reasonable. |
598 | | 514 | | || highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0. |
599 +---------+--------------------------- 515 +---------+--------------------------------+------------------------------------------------------------------------------------+
600 | 4 | amd_pstate_ut_check_freq 516 | 4 | amd_pstate_ut_check_freq || Check if the each frequency values and max freq when set support boost mode |
601 | | 517 | | | are reasonable. |
602 | | 518 | | || max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0 |
603 | | 519 | | || If boost is not active but supported, this maximum frequency will be larger than |
604 | | 520 | | | the one in ``cpuinfo``. |
605 +---------+--------------------------- 521 +---------+--------------------------------+------------------------------------------------------------------------------------+
606 522
607 2). Tbench test 523 2). Tbench test
608 524
609 Test and monitor the cpu changes when 525 Test and monitor the cpu changes when running tbench benchmark under the specified governor.
610 These changes include desire performan 526 These changes include desire performance, frequency, load, performance, energy etc.
611 The specified governor is ondemand or 527 The specified governor is ondemand or schedutil.
612 Tbench can also be tested on the ``acp 528 Tbench can also be tested on the ``acpi-cpufreq`` kernel driver for comparison.
613 529
614 3). Gitsource test 530 3). Gitsource test
615 531
616 Test and monitor the cpu changes when 532 Test and monitor the cpu changes when running gitsource benchmark under the specified governor.
617 These changes include desire performan 533 These changes include desire performance, frequency, load, time, energy etc.
618 The specified governor is ondemand or 534 The specified governor is ondemand or schedutil.
619 Gitsource can also be tested on the `` 535 Gitsource can also be tested on the ``acpi-cpufreq`` kernel driver for comparison.
620 536
621 #. How to execute the tests 537 #. How to execute the tests
622 538
623 We use test module in the kselftest framewo 539 We use test module in the kselftest frameworks to implement it.
624 We create ``amd-pstate-ut`` module and tie 540 We create ``amd-pstate-ut`` module and tie it into kselftest.(for
625 details refer to Linux Kernel Selftests [4] 541 details refer to Linux Kernel Selftests [4]_).
626 542
627 1). Build 543 1). Build
628 544
629 + open the :c:macro:`CONFIG_X86_AMD_PS 545 + open the :c:macro:`CONFIG_X86_AMD_PSTATE` configuration option.
630 + set the :c:macro:`CONFIG_X86_AMD_PST 546 + set the :c:macro:`CONFIG_X86_AMD_PSTATE_UT` configuration option to M.
631 + make project 547 + make project
632 + make selftest :: 548 + make selftest ::
633 549
634 $ cd linux 550 $ cd linux
635 $ make -C tools/testing/selftests 551 $ make -C tools/testing/selftests
636 552
637 + make perf :: 553 + make perf ::
638 554
639 $ cd tools/perf/ 555 $ cd tools/perf/
640 $ make 556 $ make
641 557
642 558
643 2). Installation & Steps :: 559 2). Installation & Steps ::
644 560
645 $ make -C tools/testing/selftests inst 561 $ make -C tools/testing/selftests install INSTALL_PATH=~/kselftest
646 $ cp tools/perf/perf /usr/bin/perf 562 $ cp tools/perf/perf /usr/bin/perf
647 $ sudo ./kselftest/run_kselftest.sh -c 563 $ sudo ./kselftest/run_kselftest.sh -c amd-pstate
648 564
649 3). Specified test case :: 565 3). Specified test case ::
650 566
651 $ cd ~/kselftest/amd-pstate 567 $ cd ~/kselftest/amd-pstate
652 $ sudo ./run.sh -t basic 568 $ sudo ./run.sh -t basic
653 $ sudo ./run.sh -t tbench 569 $ sudo ./run.sh -t tbench
654 $ sudo ./run.sh -t tbench -m acpi-cpuf 570 $ sudo ./run.sh -t tbench -m acpi-cpufreq
655 $ sudo ./run.sh -t gitsource 571 $ sudo ./run.sh -t gitsource
656 $ sudo ./run.sh -t gitsource -m acpi-c 572 $ sudo ./run.sh -t gitsource -m acpi-cpufreq
657 $ ./run.sh --help 573 $ ./run.sh --help
658 ./run.sh: illegal option -- - 574 ./run.sh: illegal option -- -
659 Usage: ./run.sh [OPTION...] 575 Usage: ./run.sh [OPTION...]
660 [-h <help>] 576 [-h <help>]
661 [-o <output-file-for-dump>] 577 [-o <output-file-for-dump>]
662 [-c <all: All testing, 578 [-c <all: All testing,
663 basic: Basic testing, 579 basic: Basic testing,
664 tbench: Tbench testing, 580 tbench: Tbench testing,
665 gitsource: Gitsource test 581 gitsource: Gitsource testing.>]
666 [-t <tbench time limit>] 582 [-t <tbench time limit>]
667 [-p <tbench process number>] 583 [-p <tbench process number>]
668 [-l <loop times for tbench>] 584 [-l <loop times for tbench>]
669 [-i <amd tracer interval>] 585 [-i <amd tracer interval>]
670 [-m <comparative test: acpi-cp 586 [-m <comparative test: acpi-cpufreq>]
671 587
672 588
673 4). Results 589 4). Results
674 590
675 + basic 591 + basic
676 592
677 When you finish test, you will get th 593 When you finish test, you will get the following log info ::
678 594
679 $ dmesg | grep "amd_pstate_ut" | tee 595 $ dmesg | grep "amd_pstate_ut" | tee log.txt
680 [12977.570663] amd_pstate_ut: 1 a 596 [12977.570663] amd_pstate_ut: 1 amd_pstate_ut_acpi_cpc_valid success!
681 [12977.570673] amd_pstate_ut: 2 a 597 [12977.570673] amd_pstate_ut: 2 amd_pstate_ut_check_enabled success!
682 [12977.571207] amd_pstate_ut: 3 a 598 [12977.571207] amd_pstate_ut: 3 amd_pstate_ut_check_perf success!
683 [12977.571212] amd_pstate_ut: 4 a 599 [12977.571212] amd_pstate_ut: 4 amd_pstate_ut_check_freq success!
684 600
685 + tbench 601 + tbench
686 602
687 When you finish test, you will get se 603 When you finish test, you will get selftest.tbench.csv and png images.
688 The selftest.tbench.csv file contains 604 The selftest.tbench.csv file contains the raw data and the drop of the comparative test.
689 The png images shows the performance, 605 The png images shows the performance, energy and performan per watt of each test.
690 Open selftest.tbench.csv : 606 Open selftest.tbench.csv :
691 607
692 +------------------------------------ 608 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
693 + Governor 609 + Governor | Round | Des-perf | Freq | Load | Performance | Energy | Performance Per Watt |
694 +------------------------------------ 610 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
695 + Unit 611 + Unit | | | GHz | | MB/s | J | MB/J |
696 +==================================== 612 +=================================================+==============+==========+=========+==========+=============+=========+======================+
697 + amd-pstate-ondemand 613 + amd-pstate-ondemand | 1 | | | | 2504.05 | 1563.67 | 158.5378 |
698 +------------------------------------ 614 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
699 + amd-pstate-ondemand 615 + amd-pstate-ondemand | 2 | | | | 2243.64 | 1430.32 | 155.2941 |
700 +------------------------------------ 616 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
701 + amd-pstate-ondemand 617 + amd-pstate-ondemand | 3 | | | | 2183.88 | 1401.32 | 154.2860 |
702 +------------------------------------ 618 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
703 + amd-pstate-ondemand 619 + amd-pstate-ondemand | Average | | | | 2310.52 | 1465.1 | 156.1268 |
704 +------------------------------------ 620 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
705 + amd-pstate-schedutil 621 + amd-pstate-schedutil | 1 | 165.329 | 1.62257 | 99.798 | 2136.54 | 1395.26 | 151.5971 |
706 +------------------------------------ 622 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
707 + amd-pstate-schedutil 623 + amd-pstate-schedutil | 2 | 166 | 1.49761 | 99.9993 | 2100.56 | 1380.5 | 150.6377 |
708 +------------------------------------ 624 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
709 + amd-pstate-schedutil 625 + amd-pstate-schedutil | 3 | 166 | 1.47806 | 99.9993 | 2084.12 | 1375.76 | 149.9737 |
710 +------------------------------------ 626 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
711 + amd-pstate-schedutil 627 + amd-pstate-schedutil | Average | 165.776 | 1.53275 | 99.9322 | 2107.07 | 1383.84 | 150.7399 |
712 +------------------------------------ 628 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
713 + acpi-cpufreq-ondemand 629 + acpi-cpufreq-ondemand | 1 | | | | 2529.9 | 1564.4 | 160.0997 |
714 +------------------------------------ 630 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
715 + acpi-cpufreq-ondemand 631 + acpi-cpufreq-ondemand | 2 | | | | 2249.76 | 1432.97 | 155.4297 |
716 +------------------------------------ 632 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
717 + acpi-cpufreq-ondemand 633 + acpi-cpufreq-ondemand | 3 | | | | 2181.46 | 1406.88 | 153.5060 |
718 +------------------------------------ 634 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
719 + acpi-cpufreq-ondemand 635 + acpi-cpufreq-ondemand | Average | | | | 2320.37 | 1468.08 | 156.4741 |
720 +------------------------------------ 636 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
721 + acpi-cpufreq-schedutil 637 + acpi-cpufreq-schedutil | 1 | | | | 2137.64 | 1385.24 | 152.7723 |
722 +------------------------------------ 638 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
723 + acpi-cpufreq-schedutil 639 + acpi-cpufreq-schedutil | 2 | | | | 2107.05 | 1372.23 | 152.0138 |
724 +------------------------------------ 640 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
725 + acpi-cpufreq-schedutil 641 + acpi-cpufreq-schedutil | 3 | | | | 2085.86 | 1365.35 | 151.2433 |
726 +------------------------------------ 642 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
727 + acpi-cpufreq-schedutil 643 + acpi-cpufreq-schedutil | Average | | | | 2110.18 | 1374.27 | 152.0136 |
728 +------------------------------------ 644 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
729 + acpi-cpufreq-ondemand VS acpi-cpufr 645 + acpi-cpufreq-ondemand VS acpi-cpufreq-schedutil | Comprison(%) | | | | -9.0584 | -6.3899 | -2.8506 |
730 +------------------------------------ 646 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
731 + amd-pstate-ondemand VS amd-pstate-s 647 + amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | | | | 8.8053 | -5.5463 | -3.4503 |
732 +------------------------------------ 648 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
733 + acpi-cpufreq-ondemand VS amd-pstate 649 + acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | | -0.4245 | -0.2029 | -0.2219 |
734 +------------------------------------ 650 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
735 + acpi-cpufreq-schedutil VS amd-pstat 651 + acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | | -0.1473 | 0.6963 | -0.8378 |
736 +------------------------------------ 652 +-------------------------------------------------+--------------+----------+---------+----------+-------------+---------+----------------------+
737 653
738 + gitsource 654 + gitsource
739 655
740 When you finish test, you will get se 656 When you finish test, you will get selftest.gitsource.csv and png images.
741 The selftest.gitsource.csv file conta 657 The selftest.gitsource.csv file contains the raw data and the drop of the comparative test.
742 The png images shows the performance, 658 The png images shows the performance, energy and performan per watt of each test.
743 Open selftest.gitsource.csv : 659 Open selftest.gitsource.csv :
744 660
745 +------------------------------------ 661 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
746 + Governor 662 + Governor | Round | Des-perf | Freq | Load | Time | Energy | Performance Per Watt |
747 +------------------------------------ 663 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
748 + Unit 664 + Unit | | | GHz | | s | J | 1/J |
749 +==================================== 665 +=================================================+==============+==========+==========+==========+=============+=========+======================+
750 + amd-pstate-ondemand 666 + amd-pstate-ondemand | 1 | 50.119 | 2.10509 | 23.3076 | 475.69 | 865.78 | 0.001155027 |
751 +------------------------------------ 667 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
752 + amd-pstate-ondemand 668 + amd-pstate-ondemand | 2 | 94.8006 | 1.98771 | 56.6533 | 467.1 | 839.67 | 0.001190944 |
753 +------------------------------------ 669 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
754 + amd-pstate-ondemand 670 + amd-pstate-ondemand | 3 | 76.6091 | 2.53251 | 43.7791 | 467.69 | 855.85 | 0.001168429 |
755 +------------------------------------ 671 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
756 + amd-pstate-ondemand 672 + amd-pstate-ondemand | Average | 73.8429 | 2.20844 | 41.2467 | 470.16 | 853.767 | 0.001171279 |
757 +------------------------------------ 673 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
758 + amd-pstate-schedutil 674 + amd-pstate-schedutil | 1 | 165.919 | 1.62319 | 98.3868 | 464.17 | 866.8 | 0.001153668 |
759 +------------------------------------ 675 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
760 + amd-pstate-schedutil 676 + amd-pstate-schedutil | 2 | 165.97 | 1.31309 | 99.5712 | 480.15 | 880.4 | 0.001135847 |
761 +------------------------------------ 677 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
762 + amd-pstate-schedutil 678 + amd-pstate-schedutil | 3 | 165.973 | 1.28448 | 99.9252 | 481.79 | 867.02 | 0.001153375 |
763 +------------------------------------ 679 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
764 + amd-pstate-schedutil 680 + amd-pstate-schedutil | Average | 165.954 | 1.40692 | 99.2944 | 475.37 | 871.407 | 0.001147569 |
765 +------------------------------------ 681 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
766 + acpi-cpufreq-ondemand 682 + acpi-cpufreq-ondemand | 1 | | | | 2379.62 | 742.96 | 0.001345967 |
767 +------------------------------------ 683 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
768 + acpi-cpufreq-ondemand 684 + acpi-cpufreq-ondemand | 2 | | | | 441.74 | 817.49 | 0.001223256 |
769 +------------------------------------ 685 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
770 + acpi-cpufreq-ondemand 686 + acpi-cpufreq-ondemand | 3 | | | | 455.48 | 820.01 | 0.001219497 |
771 +------------------------------------ 687 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
772 + acpi-cpufreq-ondemand 688 + acpi-cpufreq-ondemand | Average | | | | 425.613 | 793.487 | 0.001260260 |
773 +------------------------------------ 689 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
774 + acpi-cpufreq-schedutil 690 + acpi-cpufreq-schedutil | 1 | | | | 459.69 | 838.54 | 0.001192548 |
775 +------------------------------------ 691 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
776 + acpi-cpufreq-schedutil 692 + acpi-cpufreq-schedutil | 2 | | | | 466.55 | 830.89 | 0.001203528 |
777 +------------------------------------ 693 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
778 + acpi-cpufreq-schedutil 694 + acpi-cpufreq-schedutil | 3 | | | | 470.38 | 837.32 | 0.001194286 |
779 +------------------------------------ 695 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
780 + acpi-cpufreq-schedutil 696 + acpi-cpufreq-schedutil | Average | | | | 465.54 | 835.583 | 0.001196769 |
781 +------------------------------------ 697 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
782 + acpi-cpufreq-ondemand VS acpi-cpufr 698 + acpi-cpufreq-ondemand VS acpi-cpufreq-schedutil | Comprison(%) | | | | 9.3810 | 5.3051 | -5.0379 |
783 +------------------------------------ 699 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
784 + amd-pstate-ondemand VS amd-pstate-s 700 + amd-pstate-ondemand VS amd-pstate-schedutil | Comprison(%) | 124.7392 | -36.2934 | 140.7329 | 1.1081 | 2.0661 | -2.0242 |
785 +------------------------------------ 701 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
786 + acpi-cpufreq-ondemand VS amd-pstate 702 + acpi-cpufreq-ondemand VS amd-pstate-ondemand | Comprison(%) | | | | 10.4665 | 7.5968 | -7.0605 |
787 +------------------------------------ 703 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
788 + acpi-cpufreq-schedutil VS amd-pstat 704 + acpi-cpufreq-schedutil VS amd-pstate-schedutil | Comprison(%) | | | | 2.1115 | 4.2873 | -4.1110 |
789 +------------------------------------ 705 +-------------------------------------------------+--------------+----------+----------+----------+-------------+---------+----------------------+
790 706
791 Reference 707 Reference
792 =========== 708 ===========
793 709
794 .. [1] AMD64 Architecture Programmer's Manual 710 .. [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming,
795 https://www.amd.com/system/files/TechDo 711 https://www.amd.com/system/files/TechDocs/24593.pdf
796 712
797 .. [2] Advanced Configuration and Power Interf 713 .. [2] Advanced Configuration and Power Interface Specification,
798 https://uefi.org/sites/default/files/re 714 https://uefi.org/sites/default/files/resources/ACPI_Spec_6_4_Jan22.pdf
799 715
800 .. [3] Processor Programming Reference (PPR) f 716 .. [3] Processor Programming Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors
801 https://www.amd.com/system/files/TechDo 717 https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip
802 718
803 .. [4] Linux Kernel Selftests, 719 .. [4] Linux Kernel Selftests,
804 https://www.kernel.org/doc/html/latest/ 720 https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html
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