1 .. SPDX-License-Identifier: GPL-2.0
2
3 ==============================================
4 Intel(R) Speed Select Technology User Guide
5 ==============================================
6
7 The Intel(R) Speed Select Technology (Intel(R)
8 collection of features that give more granular
9 With Intel(R) SST, one server can be configure
10 variety of diverse workload requirements.
11
12 Refer to the links below for an overview of th
13
14 - https://www.intel.com/content/www/us/en/arch
15 - https://builders.intel.com/docs/networkbuild
16
17 These capabilities are further enhanced in som
18 server platforms where these features can be e
19 dynamically without pre-configuring via BIOS s
20 configuration is done via mailbox commands to
21 and configure these features is by using the I
22
23 This document explains how to use the Intel Sp
24 control Intel(R) SST features. This document g
25 how these commands change the power and perfor
26 test. Using this tool as an example, customers
27 implemented in the tool in their production so
28
29 intel-speed-select configuration tool
30 ======================================
31
32 Most Linux distribution packages may include t
33 it can be built by downloading the Linux kerne
34 downloaded, the tool can be built without buil
35
36 From the kernel tree, run the following comman
37
38 # cd tools/power/x86/intel-speed-select/
39 # make
40 # make install
41
42 Getting Help
43 ------------
44
45 To get help with the tool, execute the command
46
47 # intel-speed-select --help
48
49 The top-level help describes arguments and fea
50 multi-level help structure in the tool. For ex
51
52 # intel-speed-select perf-profile --help
53
54 To get help on a command, another level of hel
55
56 # intel-speed-select perf-profile info --help
57
58 Summary of platform capability
59 ------------------------------
60 To check the current platform and driver capab
61
62 #intel-speed-select --info
63
64 For example on a test system::
65
66 # intel-speed-select --info
67 Intel(R) Speed Select Technology
68 Executing on CPU model: X
69 Platform: API version : 1
70 Platform: Driver version : 1
71 Platform: mbox supported : 1
72 Platform: mmio supported : 1
73 Intel(R) SST-PP (feature perf-profile) is sup
74 TDP level change control is unlocked, max lev
75 Intel(R) SST-TF (feature turbo-freq) is suppo
76 Intel(R) SST-BF (feature base-freq) is not su
77 Intel(R) SST-CP (feature core-power) is suppo
78
79 Intel(R) Speed Select Technology - Performance
80 ----------------------------------------------
81
82 This feature allows configuration of a server
83 performance requirements. This helps users dur
84 to choose a specific server configuration stat
85 Technology - Performance Profile (Intel(R) SST
86 that allows multiple optimized performance pro
87 defines a set of CPUs that need to be online a
88 guaranteed base frequency. Once the user issue
89 performance profile and meet CPU online/offlin
90 a change in the base frequency dynamically. Th
91 "perf-profile" when using the Intel Speed Sele
92
93 Number or performance levels
94 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
95
96 There can be multiple performance profiles on
97 profiles, execute the command below::
98
99 # intel-speed-select perf-profile get-config-
100 Intel(R) Speed Select Technology
101 Executing on CPU model: X
102 package-0
103 die-0
104 cpu-0
105 get-config-levels:4
106 package-1
107 die-0
108 cpu-14
109 get-config-levels:4
110
111 On this system under test, there are 4 perform
112 base performance profile (which is performance
113
114 Lock/Unlock status
115 ~~~~~~~~~~~~~~~~~~
116
117 Even if there are multiple performance profile
118 are locked. If they are locked, users cannot i
119 performance state. It is possible that there i
120 with your system vendor.
121
122 To check if the system is locked, execute the
123
124 # intel-speed-select perf-profile get-lock-st
125 Intel(R) Speed Select Technology
126 Executing on CPU model: X
127 package-0
128 die-0
129 cpu-0
130 get-lock-status:0
131 package-1
132 die-0
133 cpu-14
134 get-lock-status:0
135
136 In this case, lock status is 0, which means th
137
138 Properties of a performance level
139 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
140
141 To get properties of a specific performance le
142
143 # intel-speed-select perf-profile info -l 0
144 Intel(R) Speed Select Technology
145 Executing on CPU model: X
146 package-0
147 die-0
148 cpu-0
149 perf-profile-level-0
150 cpu-count:28
151 enable-cpu-mask:000003ff,f0003fff
152 enable-cpu-list:0,1,2,3,4,5,6,7,8,9,10
153 thermal-design-power-ratio:26
154 base-frequency(MHz):2600
155 speed-select-turbo-freq:disabled
156 speed-select-base-freq:disabled
157 ...
158 ...
159
160 Here -l option is used to specify a performanc
161
162 If the option -l is omitted, then this command
163 the performance levels. The above command is p
164 performance level 0.
165
166 For this performance profile, the list of CPUs
167 "enable-cpu-mask/enable-cpu-list" at the max c
168 condition is met, then base frequency of 2600
169 understand more, execute "intel-speed-select p
170 level 4::
171
172 # intel-speed-select perf-profile info -l 4
173 Intel(R) Speed Select Technology
174 Executing on CPU model: X
175 package-0
176 die-0
177 cpu-0
178 perf-profile-level-4
179 cpu-count:28
180 enable-cpu-mask:000000fa,f0000faf
181 enable-cpu-list:0,1,2,3,5,7,8,9,10,11,
182 thermal-design-power-ratio:28
183 base-frequency(MHz):2800
184 speed-select-turbo-freq:disabled
185 speed-select-base-freq:unsupported
186 ...
187 ...
188
189 There are fewer CPUs in the "enable-cpu-mask/e
190 the user only keeps these CPUs online and the
191 frequency is increased to 2.8 GHz compared to
192
193 Get current performance level
194 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
195
196 To get the current performance level, execute:
197
198 # intel-speed-select perf-profile get-config-
199 Intel(R) Speed Select Technology
200 Executing on CPU model: X
201 package-0
202 die-0
203 cpu-0
204 get-config-current_level:0
205
206 First verify that the base_frequency displayed
207
208 # cat /sys/devices/system/cpu/cpu0/cpufreq/ba
209 2600000
210
211 This matches the base-frequency (MHz) field va
212 "perf-profile info" command for performance le
213 KHz).
214
215 To check if the average frequency is equal to
216 workload, disable turbo::
217
218 # echo 1 > /sys/devices/system/cpu/intel_pstat
219
220 Then runs a busy workload on all CPUs, for exa
221
222 #stress -c 64
223
224 To verify the base frequency, run turbostat::
225
226 #turbostat -c 0-13 --show Package,Core,CPU,Bz
227
228 Package Core CPU Bzy_MHz
229 - - 2600
230 0 0 0 2600
231 0 1 1 2600
232 0 2 2 2600
233 0 3 3 2600
234 0 4 4 2600
235 . . . .
236
237
238 Changing performance level
239 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
240
241 To the change the performance level to 4, exec
242
243 # intel-speed-select -d perf-profile set-conf
244 Intel(R) Speed Select Technology
245 Executing on CPU model: X
246 package-0
247 die-0
248 cpu-0
249 perf-profile
250 set_tdp_level:success
251
252 In the command above, "-o" is optional. If it
253 offline CPUs which are not present in the enab
254 level.
255
256 Now if the base_frequency is checked::
257
258 #cat /sys/devices/system/cpu/cpu0/cpufreq/bas
259 2800000
260
261 Which shows that the base frequency now increa
262 level 0 to 2800 MHz at performance level 4. As
263 use fewer CPUs, can see a boost of 200 MHz com
264
265 Changing performance level via BMC Interface
266 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
267
268 It is possible to change SST-PP level using ou
269 remote management console, through BMC "Basebo
270 interface). This mode is supported from the Sa
271 generation. The kernel and tool change to supp
272 kernel version 5.18. To enable this feature, k
273 "CONFIG_INTEL_HFI_THERMAL" is required. The mi
274 is "v1.12" to support this feature, which is p
275
276 To support such configuration, this tool can b
277 a command line option --oob::
278
279 # intel-speed-select --oob
280 Intel(R) Speed Select Technology
281 Executing on CPU model:143[0x8f]
282 OOB mode is enabled and will run as daemon
283
284 In this mode the tool will online/offline CPUs
285 level.
286
287 Check presence of other Intel(R) SST features
288 ---------------------------------------------
289
290 Each of the performance profiles also specifie
291 other two Intel(R) SST features (Intel(R) Spee
292 (Intel(R) SST-BF) and Intel(R) Speed Select Te
293 SST-TF)).
294
295 For example, from the output of "perf-profile
296 4:
297
298 For level 0::
299 speed-select-turbo-freq:disabled
300 speed-select-base-freq:disabled
301
302 For level 4::
303 speed-select-turbo-freq:disabled
304 speed-select-base-freq:unsupported
305
306 Given these results, the "speed-select-base-fr
307 changed from "disabled" to "unsupported" compa
308
309 This means that at performance level 4, the "s
310 not supported. However, at performance level 0
311 currently "disabled", meaning the user has not
312 "speed-select-turbo-freq" (Intel(R) SST-TF) is
313 levels, but currently not activated by the use
314
315 The Intel(R) SST-BF and the Intel(R) SST-TF fe
316 technology called Intel(R) Speed Select Techno
317 The platform firmware enables this feature whe
318 is supported on a platform.
319
320 Intel(R) Speed Select Technology Core Power (I
321 ----------------------------------------------
322
323 Intel(R) Speed Select Technology Core Power (I
324 allows users to define per core priority. This
325 power among cores when there is a power constr
326 class of service (CLOS) configuration.
327
328 The user can configure up to 4 class of servic
329 configuration allows definitions of parameters
330 can be limited and power is distributed. Each
331 service and hence an associated priority. The
332 at per CPU level.
333
334 Enable CLOS based prioritization
335 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
336
337 To use CLOS based prioritization feature, firm
338 and use a priority type. There is a default pe
339 can be changed with optional command line para
340
341 To enable and check the options, execute::
342
343 # intel-speed-select core-power enable --help
344 Intel(R) Speed Select Technology
345 Executing on CPU model: X
346 Enable core-power for a package/die
347 Clos Enable: Specify priority type wit
348 0: Proportional, 1: Ordered
349
350 There are two types of priority types:
351
352 - Ordered
353
354 Priority for ordered throttling is defined bas
355 CLOS group. Where CLOS0 gets highest priority
356
357 Priority order is:
358 CLOS0 > CLOS1 > CLOS2 > CLOS3.
359
360 - Proportional
361
362 When proportional priority is used, there is a
363 frequency_weight, which can be specified per C
364 proportional priority is to provide each core
365 distribute all remaining (excess/deficit) budg
366 weight. This proportional priority can be conf
367 command.
368
369 To enable with the platform default priority t
370
371 # intel-speed-select core-power enable
372 Intel(R) Speed Select Technology
373 Executing on CPU model: X
374 package-0
375 die-0
376 cpu-0
377 core-power
378 enable:success
379 package-1
380 die-0
381 cpu-6
382 core-power
383 enable:success
384
385 The scope of this enable is per package or die
386 multiple dies. To check if CLOS is enabled and
387 info" command can be used. For example to chec
388 on CPU 0, execute::
389
390 # intel-speed-select -c 0 core-power info
391 Intel(R) Speed Select Technology
392 Executing on CPU model: X
393 package-0
394 die-0
395 cpu-0
396 core-power
397 support-status:supported
398 enable-status:enabled
399 clos-enable-status:enabled
400 priority-type:proportional
401 package-1
402 die-0
403 cpu-24
404 core-power
405 support-status:supported
406 enable-status:enabled
407 clos-enable-status:enabled
408 priority-type:proportional
409
410 Configuring CLOS groups
411 ~~~~~~~~~~~~~~~~~~~~~~~
412
413 Each CLOS group has its own attributes includi
414 desired. These parameters can be configured wi
415 Defaults will be used if user skips setting a
416 mandatory. To check core-power config options,
417
418 # intel-speed-select core-power config --help
419 Intel(R) Speed Select Technology
420 Executing on CPU model: X
421 Set core-power configuration for one of the f
422 Specify targeted clos id with [--clos|
423 Specify clos Proportional Priority [--
424 Specify clos min in MHz with [--min|-n
425 Specify clos max in MHz with [--max|-m
426
427 For example::
428
429 # intel-speed-select core-power config -c 0
430 Intel(R) Speed Select Technology
431 Executing on CPU model: X
432 clos epp is not specified, default: 0
433 clos frequency weight is not specified, defau
434 clos min is not specified, default: 0 MHz
435 clos max is not specified, default: 25500 MHz
436 clos desired is not specified, default: 0
437 package-0
438 die-0
439 cpu-0
440 core-power
441 config:success
442 package-1
443 die-0
444 cpu-6
445 core-power
446 config:success
447
448 The user has the option to change defaults. Fo
449 "min" and set the base frequency to always get
450
451 Get the current CLOS configuration
452 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
453
454 To check the current configuration, "core-powe
455 example, to get the configuration of CLOS 0::
456
457 # intel-speed-select core-power get-config -c
458 Intel(R) Speed Select Technology
459 Executing on CPU model: X
460 package-0
461 die-0
462 cpu-0
463 core-power
464 clos:0
465 epp:0
466 clos-proportional-priority:0
467 clos-min:0 MHz
468 clos-max:Max Turbo frequency
469 clos-desired:0 MHz
470 package-1
471 die-0
472 cpu-24
473 core-power
474 clos:0
475 epp:0
476 clos-proportional-priority:0
477 clos-min:0 MHz
478 clos-max:Max Turbo frequency
479 clos-desired:0 MHz
480
481 Associating a CPU with a CLOS group
482 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
483
484 To associate a CPU to a CLOS group "core-power
485
486 # intel-speed-select core-power assoc --help
487 Intel(R) Speed Select Technology
488 Executing on CPU model: X
489 Associate a clos id to a CPU
490 Specify targeted clos id with [--clos|
491
492
493 For example to associate CPU 10 to CLOS group
494
495 # intel-speed-select -c 10 core-power assoc -
496 Intel(R) Speed Select Technology
497 Executing on CPU model: X
498 package-0
499 die-0
500 cpu-10
501 core-power
502 assoc:success
503
504 Once a CPU is associated, its sibling CPUs are
505 Once associated, avoid changing Linux "cpufreq
506 limits.
507
508 To check the existing association for a CPU, "
509 be used. For example, to get association of CP
510
511 # intel-speed-select -c 10 core-power get-ass
512 Intel(R) Speed Select Technology
513 Executing on CPU model: X
514 package-1
515 die-0
516 cpu-10
517 get-assoc
518 clos:3
519
520 This shows that CPU 10 is part of a CLOS group
521
522
523 Disable CLOS based prioritization
524 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
525
526 To disable, execute::
527
528 # intel-speed-select core-power disable
529
530 Some features like Intel(R) SST-TF can only be
531 is enabled. For this reason, disabling while I
532 Intel(R) SST-TF to fail. This will cause the "
533 if Intel(R) SST-TF is already enabled. In turn
534 feature must be disabled first.
535
536 Intel(R) Speed Select Technology - Base Freque
537 ----------------------------------------------
538
539 The Intel(R) Speed Select Technology - Base Fr
540 the user control base frequency. If some criti
541 constant high guaranteed performance, then thi
542 the thread at higher base frequency on specifi
543 CPUs) at the cost of lower base frequency (low
544 This feature does not require offline of the l
545
546 The support of Intel(R) SST-BF depends on the
547 Performance Profile (Intel(R) SST-PP) performa
548 possible that only certain performance levels
549 possible that only base performance level (lev
550 SST-BF. Consequently, first select the desired
551 feature.
552
553 In the system under test here, Intel(R) SST-BF
554 performance level 0, but currently disabled. F
555
556 # intel-speed-select -c 0 perf-profile info -
557 Intel(R) Speed Select Technology
558 Executing on CPU model: X
559 package-0
560 die-0
561 cpu-0
562 perf-profile-level-0
563 ...
564
565 speed-select-base-freq:disabled
566 ...
567
568 Before enabling Intel(R) SST-BF and measuring
569 performance, execute some workload and measure
570 performance to compare against.
571
572 Here the user wants more guaranteed performanc
573 that turbo is disabled. To disable turbo, exec
574
575 #echo 1 > /sys/devices/system/cpu/intel_pstate
576
577 Based on the output of the "intel-speed-select
578 frequency of guaranteed frequency 2600 MHz.
579
580
581 Measure baseline performance for comparison
582 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
583
584 To compare, pick a multi-threaded workload whe
585 separate CPUs. "Hackbench pipe" test is a good
586 performance using Intel(R) SST-BF.
587
588 Below, the workload is measuring average sched
589 number means better performance::
590
591 # taskset -c 3,4 perf bench -r 100 sched pipe
592 # Running 'sched/pipe' benchmark:
593 # Executed 1000000 pipe operations between tw
594 Total time: 6.102 [sec]
595 6.102445 usecs/op
596 163868 ops/sec
597
598 While running the above test, if we take turbo
599 2 of the CPUs are busy and reaching max. frequ
600 frequency as the turbo is disabled). The turbo
601
602 #turbostat -c 0-13 --show Package,Core,CPU,Bz
603 Package Core CPU Bzy_MHz
604 0 0 0 1000
605 0 1 1 1005
606 0 2 2 1000
607 0 3 3 2600
608 0 4 4 2600
609 0 5 5 1000
610 0 6 6 1000
611 0 7 7 1005
612 0 8 8 1005
613 0 9 9 1000
614 0 10 10 1000
615 0 11 11 995
616 0 12 12 1000
617 0 13 13 1000
618
619 From the above turbostat output, both CPU 3 an
620 full guaranteed frequency of 2600 MHz.
621
622 Intel(R) SST-BF Capabilities
623 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
624
625 To get capabilities of Intel(R) SST-BF for the
626 execute::
627
628 # intel-speed-select base-freq info -l 0
629 Intel(R) Speed Select Technology
630 Executing on CPU model: X
631 package-0
632 die-0
633 cpu-0
634 speed-select-base-freq
635 high-priority-base-frequency(MHz):3000
636 high-priority-cpu-mask:00000216,000021
637 high-priority-cpu-list:5,6,8,13,33,34,
638 low-priority-base-frequency(MHz):2400
639 tjunction-temperature(C):125
640 thermal-design-power(W):205
641
642 The above capabilities show that there are som
643 offer base frequency of 3000 MHz compared to t
644 performance levels. Nevertheless, these CPUs a
645 via high-priority-cpu-list/high-priority-cpu-m
646 feature is selected, the low priorities CPUs (
647 high-priority-cpu-list) can only offer up to 2
648 clipping of low priority CPUs is acceptable, t
649 SST-BF feature particularly for the above "sch
650 CPUs are used, they can be scheduled on high p
651 400 MHz.
652
653 Enable Intel(R) SST-BF
654 ~~~~~~~~~~~~~~~~~~~~~~
655
656 To enable Intel(R) SST-BF feature, execute::
657
658 # intel-speed-select base-freq enable -a
659 Intel(R) Speed Select Technology
660 Executing on CPU model: X
661 package-0
662 die-0
663 cpu-0
664 base-freq
665 enable:success
666 package-1
667 die-0
668 cpu-14
669 base-freq
670 enable:success
671
672 In this case, -a option is optional. This not
673 also adjusts the priority of cores using Intel
674 Power (Intel(R) SST-CP) features. This option
675 Intel(R) Speed Select Technology - Performance
676 maximum performance so that the hardware will
677 for each CPU.
678
679 If -a option is not used, then the following s
680 Intel(R) SST-BF:
681
682 - Discover Intel(R) SST-BF and note low and hi
683 - Note the high priority CPU list
684 - Enable CLOS using core-power feature set
685 - Configure CLOS parameters. Use CLOS.min to s
686 - Subscribe desired CPUs to CLOS groups
687
688 With this configuration, if the same workload
689 workload to high priority CPUs (CPU 5 and 6 in
690
691 #taskset -c 5,6 perf bench -r 100 sched pipe
692 # Running 'sched/pipe' benchmark:
693 # Executed 1000000 pipe operations between tw
694 Total time: 5.627 [sec]
695 5.627922 usecs/op
696 177685 ops/sec
697
698 This way, by enabling Intel(R) SST-BF, the per
699 improved (latency reduced) by 7.79%. From the
700 observed that the high priority CPUs reached 3
701 The turbostat output::
702
703 #turbostat -c 0-13 --show Package,Core,CPU,Bz
704 Package Core CPU Bzy_MHz
705 0 0 0 2151
706 0 1 1 2166
707 0 2 2 2175
708 0 3 3 2175
709 0 4 4 2175
710 0 5 5 3000
711 0 6 6 3000
712 0 7 7 2180
713 0 8 8 2662
714 0 9 9 2176
715 0 10 10 2175
716 0 11 11 2176
717 0 12 12 2176
718 0 13 13 2661
719
720 Disable Intel(R) SST-BF
721 ~~~~~~~~~~~~~~~~~~~~~~~
722
723 To disable the Intel(R) SST-BF feature, execut
724
725 # intel-speed-select base-freq disable -a
726
727
728 Intel(R) Speed Select Technology - Turbo Frequ
729 ----------------------------------------------
730
731 This feature enables the ability to set differ
732 to cores based on the priority. By using this
733 configured to get higher turbo frequency by de
734 the cost of lower or no turbo frequency on the
735
736 For this reason, this feature is only useful w
737 CPUs, but the user wants some configurable opt
738 some CPUs.
739
740 The support of Intel(R) Speed Select Technolog
741 depends on the Intel(R) Speed Select Technolog
742 SST-PP) performance level configuration. It is
743 performance level supports Intel(R) SST-TF. It
744 performance level (level = 0) has the support
745 select the desired performance level to enable
746
747 In the system under test here, Intel(R) SST-TF
748 performance level 0, but currently disabled::
749
750 # intel-speed-select -c 0 perf-profile info -
751 Intel(R) Speed Select Technology
752 package-0
753 die-0
754 cpu-0
755 perf-profile-level-0
756 ...
757 ...
758 speed-select-turbo-freq:disabled
759 ...
760 ...
761
762
763 To check if performance can be improved using
764 frequency properties with Intel(R) SST-TF enab
765 capability of this system.
766
767 Get Base turbo capability
768 ~~~~~~~~~~~~~~~~~~~~~~~~~
769
770 To get the base turbo capability of performanc
771
772 # intel-speed-select perf-profile info -l 0
773 Intel(R) Speed Select Technology
774 Executing on CPU model: X
775 package-0
776 die-0
777 cpu-0
778 perf-profile-level-0
779 ...
780 ...
781 turbo-ratio-limits-sse
782 bucket-0
783 core-count:2
784 max-turbo-frequency(MHz):3200
785 bucket-1
786 core-count:4
787 max-turbo-frequency(MHz):3100
788 bucket-2
789 core-count:6
790 max-turbo-frequency(MHz):3100
791 bucket-3
792 core-count:8
793 max-turbo-frequency(MHz):3100
794 bucket-4
795 core-count:10
796 max-turbo-frequency(MHz):3100
797 bucket-5
798 core-count:12
799 max-turbo-frequency(MHz):3100
800 bucket-6
801 core-count:14
802 max-turbo-frequency(MHz):3100
803 bucket-7
804 core-count:16
805 max-turbo-frequency(MHz):3100
806
807 Based on the data above, when all the CPUS are
808 MHz can be achieved. If there is some busy wor
809 and on CPU 12 and 13, execute "hackbench pipe"
810
811 # taskset -c 12,13 perf bench -r 100 sched pi
812 # Running 'sched/pipe' benchmark:
813 # Executed 1000000 pipe operations between tw
814 Total time: 5.705 [sec]
815 5.705488 usecs/op
816 175269 ops/sec
817
818 The turbostat output::
819
820 #turbostat -c 0-13 --show Package,Core,CPU,Bz
821 Package Core CPU Bzy_MHz
822 0 0 0 3000
823 0 1 1 3000
824 0 2 2 3000
825 0 3 3 3000
826 0 4 4 3000
827 0 5 5 3100
828 0 6 6 3100
829 0 7 7 3000
830 0 8 8 3100
831 0 9 9 3000
832 0 10 10 3000
833 0 11 11 3000
834 0 12 12 3100
835 0 13 13 3100
836
837 Based on turbostat output, the performance is
838 MHz. To check if the hackbench performance can
839 13, first check the capability of the Intel(R)
840 level.
841
842 Get Intel(R) SST-TF Capability
843 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
844
845 To get the capability, the "turbo-freq info" c
846
847 # intel-speed-select turbo-freq info -l 0
848 Intel(R) Speed Select Technology
849 Executing on CPU model: X
850 package-0
851 die-0
852 cpu-0
853 speed-select-turbo-freq
854 bucket-0
855 high-priority-cores-count:2
856 high-priority-max-frequency(MHz):3
857 high-priority-max-avx2-frequency(M
858 high-priority-max-avx512-frequency
859 bucket-1
860 high-priority-cores-count:4
861 high-priority-max-frequency(MHz):3
862 high-priority-max-avx2-frequency(M
863 high-priority-max-avx512-frequency
864 bucket-2
865 high-priority-cores-count:6
866 high-priority-max-frequency(MHz):3
867 high-priority-max-avx2-frequency(M
868 high-priority-max-avx512-frequency
869 speed-select-turbo-freq-clip-frequen
870 low-priority-max-frequency(MHz):26
871 low-priority-max-avx2-frequency(MH
872 low-priority-max-avx512-frequency(
873
874 Based on the output above, there is an Intel(R
875 two high priority cores. If only two high prio
876 turbo frequency on those cores can be increase
877 more than the base turbo capability for all co
878
879 In turn, for the hackbench workload, two CPUs
880 rest as low priority. One side effect is that
881 cores will be clipped to a lower frequency of
882
883 Enable Intel(R) SST-TF
884 ~~~~~~~~~~~~~~~~~~~~~~
885
886 To enable Intel(R) SST-TF, execute::
887
888 # intel-speed-select -c 12,13 turbo-freq enab
889 Intel(R) Speed Select Technology
890 Executing on CPU model: X
891 package-0
892 die-0
893 cpu-12
894 turbo-freq
895 enable:success
896 package-0
897 die-0
898 cpu-13
899 turbo-freq
900 enable:success
901 package--1
902 die-0
903 cpu-63
904 turbo-freq --auto
905 enable:success
906
907 In this case, the option "-a" is optional. If
908 feature and also sets the CPUs to high and low
909 Select Technology Core Power (Intel(R) SST-CP)
910 with "-c" arguments are marked as high priorit
911
912 If -a option is not used, then the following s
913 Intel(R) SST-TF:
914
915 - Discover Intel(R) SST-TF and note buckets of
916
917 - Enable CLOS using core-power feature set - C
918
919 - Subscribe desired CPUs to CLOS groups making
920
921 If the same hackbench workload is executed, sc
922 priority CPUs::
923
924 #taskset -c 12,13 perf bench -r 100 sched pip
925 # Running 'sched/pipe' benchmark:
926 # Executed 1000000 pipe operations between tw
927 Total time: 5.510 [sec]
928 5.510165 usecs/op
929 180826 ops/sec
930
931 This improved performance by around 3.3% impro
932 turbostat output will show that the CPU 12 and
933 The turbostat output::
934
935 #turbostat -c 0-13 --show Package,Core,CPU,Bz
936 Package Core CPU Bzy_MHz
937 ...
938 0 12 12 3200
939 0 13 13 3200
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