On 7 November 2013 12:32, Catalin Marinas <[email protected]> wrote:
> Hi Vincent,
>
> (for whatever reason, the text is wrapped and results hard to read)
Yes, i have just seen that. It looks like gmail has wrapped the lines.
I have added the results which should not be wrapped, at the end of this email
>
>
> On Thu, Nov 07, 2013 at 10:54:30AM +0000, Vincent Guittot wrote:
>> During the Energy-aware scheduling mini-summit, we spoke about benches
>> that should be used to evaluate the modifications of the scheduler.
>> I’d like to propose a bench that uses cyclictest to measure the wake
>> up latency and the power consumption. The goal of this bench is to
>> exercise the scheduler with various sleeping period and get the
>> average wakeup latency. The range of the sleeping period must cover
>> all residency times of the idle state table of the platform. I have
>> run such tests on a tc2 platform with the packing tasks patchset.
>> I have use the following command:
>> #cyclictest -t <number of cores> -q -e 10000000 -i <500-12000> -d 150 -l 2000
>
> cyclictest could be a good starting point but we need to improve it to
> allow threads of different loads, possibly starting multiple processes
> (can be done with a script), randomly varying load threads. These
> parameters should be loaded from a file so that we can have multiple
> configurations (per SoC and per use-case). But the big risk is that we
> try to optimise the scheduler for something which is not realistic.
The goal of this simple bench is to measure the wake up latency and the
reachable value of the scheduler on a platform but not to emulate a "real" use
case. In the same way than sched-pipe tests a specific behavior of the
scheduler, this bench tests the wake up latency of a system.
Starting multi processes and adding some loads can also be useful but the
target will be a bit different from wake up latency. I have one concern with
randomness because it prevents from having repeatable and comparable tests and
results.
I agree that we have to test "real" use cases but it doesn't prevent from
testing the limit of a characteristic on a system
>
>
> We are working on describing some basic scenarios (plain English for
> now) and one of them could be video playing with threads for audio and
> video decoding with random change in the workload.
>
> So I think the first step should be a set of tools/scripts to analyse
> the scheduler behaviour, both in terms of latency and power, and these
> can use perf sched. We can then run some real life scenarios (e.g.
> Android video playback) and build a benchmark that matches such
> behaviour as close as possible. We can probably use (or improve) perf
> sched replay to also simulate such workload (we may need additional
> features like thread dependencies).
>
>> The figures below give the average wakeup latency and power
>> consumption for default scheduler behavior, packing tasks at cluster
>> level and packing tasks at core level. We can see both wakeup latency
>> and power consumption variation. The detailed result is not a simple
>> single value which makes comparison not so easy but the average of all
>> measurements should give us a usable “score”.
>
> How did you assess the power/energy?
I have use the embedded joule meter of the tc2.
>
> Thanks.
>
> --
> Catalin
| Default average results | Cluster Packing
average results | Core Packing average results
| Latency stddev A7 energy A15 energy | Latency stddev
A7 energy A15 energy | Latency stddev A7 energy A15 energy
| (us) (J) (J) | (us)
(J) (J) | (us) (J) (J)
| 879 794890 2364175 | 416
879688 12750 | 189 897452 30052
Cyclictest | Default | Packing at Cluster
level | Packing at Core level
Interval | Latency stddev A7 energy A15 energy | Latency stddev
A7 energy A15 energy | Latency stddev A7 energy A15 energy
(us) | (us) (J) (J) | (us)
(J) (J) | (us) (J) (J)
500 24 1 1147477 2479576 21 1
1136768 11693 22 1 1126062 30138
700 22 1 1136084 3058419 21 0
1125280 11761 21 1 1109950 23503
900 22 1 1136017 3036768 21 1
1112542 12017 20 0 1101089 23733
1100 24 1 1132964 2506132 21 0
1109039 12248 21 1 1091832 23621
1300 24 1 1123896 2488459 21 0
1099308 12015 21 1 1086301 23264
1500 24 1 1120842 2488272 21 0
1099811 12685 20 0 1083658 22499
1700 41 38 1117166 3042091 21 0
1090920 12393 21 1 1080387 23015
1900 119 182 1120552 2737555 21 0
1087900 11900 21 1 1078711 23177
2100 167 195 1122425 3210655 22 2
1090420 11900 20 1 1077985 22639
2300 152 156 1119854 2497773 43 22
1087278 11921 21 1 1075943 26282
2500 182 163 1120818 2365870 63 29
1089169 11551 21 0 1073717 24290
2700 439 202 1058952 3058516 107 41
1077955 12122 21 0 1070951 23126
2900 570 268 1028238 3099162 148 30
1067562 13287 24 1 1064200 24260
3100 751 137 946512 3158095 178 30
1059395 12236 29 1 1058887 23225
3300 696 203 964822 3042524 206 28
1041194 13934 36 1 1056656 23941
3500 728 191 959398 3006066 235 36
1028150 13387 44 3 1045841 23873
3700 844 138 921780 3033189 245 31
1019065 14582 62 6 1034466 22501
3900 815 172 925600 2862994 273 33
1001974 12091 80 9 1014650 24444
4100 870 179 897616 2940444 279 35
996226 12014 88 11 1030588 25461
4300 979 119 846912 2996911 306 36
980075 12641 100 12 1035173 24832
4500 891 168 863631 2760879 336 45
955072 12016 126 12 993256 23929
4700 943 110 836333 2796629 351 39
942390 12902 125 15 996548 24637
4900 997 118 800205 2743317 391 49
917067 12868 134 23 1011089 25266
5100 1050 114 789152 2693104 408 53
903123 12033 196 22 894294 25142
5300 1052 111 769544 2668315 425 54
895006 12264 171 19 933356 25873
5500 1002 179 794222 2554432 430 45
886025 12007 171 18 938921 24382
5700 1002 180 786714 2441228 436 46
878043 12258 172 14 944908 30291
5900 1117 90 742883 2554813 471 53
864134 12471 170 12 957811 25119
6100 1166 92 734510 2566381 479 68
854384 12579 190 16 926807 25544
6300 1132 123 738812 2447974 488 57
849740 12968 216 10 882940 26546
6500 1123 150 743870 2323338 495 52
836256 12472 210 20 896639 25149
6700 1173 139 724691 2330720 522 70
822678 12949 269 27 800938 28653
6900 1054 112 725451 2953919 522 69
822682 12184 261 26 785269 28199
7100 1098 174 731504 2255090 502 87
820909 13072 216 15 870777 25336
7300 1244 156 702596 2317562 531 88
808677 12770 247 18 813081 28126
7500 1181 143 694538 2226994 545 90
796698 12368 226 14 862177 26597
7700 1189 147 681836 2183167 555 87
799215 12499 250 17 797699 26342
7900 1082 149 694010 1926757 555 90
791777 13137 243 20 824061 26772
8100 1068 145 678222 2791019 552 80
785043 13071 266 16 781563 26579
8300 1102 135 690978 1851892 582 136
781035 13067 267 18 782060 26683
8500 1190 191 653566 2068057 574 127
777348 13139 262 21 800524 27086
8700 1172 185 666525 2031543 602 104
778754 13364 228 13 884802 25340
8900 1024 179 685123 1689661 594 98
768617 13753 266 20 801557 26075
9100 1077 166 658295 1756367 615 101
759656 13297 308 19 739619 25677
9300 1211 203 618593 2055230 606 111
753652 13231 319 23 743849 26041
9500 1163 189 627123 1794459 615 125
751993 13174 264 19 865898 25795
9700 1240 202 589520 1983417 649 157
738596 13473 326 71 742113 25528
9900 1188 207 612908 1830208 635 125
725890 14240 299 40 770069 24714
10100 1168 219 596998 1781611 647 132
718260 13834 245 35 905581 24854
10300 1083 222 615543 1506529 641 130
700636 13108 401 24 643222 26497
10500 1183 210 573875 1753476 648 169
708408 12756 392 30 636559 28712
10700 1217 234 526025 2014191 648 165
696542 13092 374 26 675566 28555
10900 1161 179 594406 1722260 647 194
698681 13715 344 45 682158 26681
11100 1185 209 578309 1919206 670 166
724562 13408 339 50 743402 28010
11300 1144 185 609694 1791436 671 136
712555 12769 307 36 762260 26575
11500 1070 188 617941 1470628 650 151
723367 12596 353 21 659704 28015
11700 1205 199 570787 1801593 673 168
706260 12568 347 12 689414 29196
11900 1216 174 563915 1761745 686 135
698164 12840 361 10 663126 27517
12100 1155 218 568867 1596189 677 159
705873 12759 309 14 774833 290747
12300 1236 187 543536 1738447 705 177
705564 13028 330 21 745009 28134
12500 1176 202 545135 1651420 696 148
697624 13280 339 20 724057 26461
Vincent
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