Source RK-KF-YF-491 V1.2.0 reports measurements for different RT Linux implementations. Increasing real-time requirements may exceed standard Linux capabilities; PREEMPT_RT patches or Xenomai can improve them. All vendor configurations, commands, logs and durations are retained; these are not ArmSoM measurements. The preface lists RK3568 kernel-4.19, RK3562/RK3588 kernel-5.10 and RK3576/RK3506 kernel-6.1, but the RK3568 test table says kernel-5.10. This source inconsistency remains unresolved. Verify each ArmSoM board SoC, SDK/BSP, RT patches, BL31, clocks and load conditions; these results do not guarantee a hard real-time bound.
ArmSoM Docs · Rockchip Linux kernel
1. Introduction to Real-Time Linux
Standard Linux aims to provide a complete, stable open-source operating system, shorten average response time, improve throughput and optimize overall functionality and average performance. It therefore does not provide hard real-time behavior. Linux-based hard real-time solutions fall into two categories. Direct kernel modification makes relatively small changes rather than extensively redesigning Linux and, under the GPL, turns it into a fully preemptible real-time system. Its disadvantage is that kernel changes cannot easily guarantee that unpredictable activities of non-real-time processes will not interfere with real-time execution. RT-patch (Real Preemption Patch) represents this approach. The dual-kernel approach adds a real-time kernel alongside Linux in kernel space and schedules standard Linux as an ordinary process on it. It can provide hard real-time behavior and readily implement new scheduling policies. Common examples are RT-Linux, RTAI (Real-Time Application Interface) and Xenomai; the dual-kernel approach offers better real-time behavior.
2. Real-time performance tests
2.1 RK3568
| Configuration | Description |
|---|---|
| CPU | 4xA55,1314 MHz(PVTPLL@0.9V@len=0x43) |
| CACHE | L1-32K,L2-0K,L3-512K |
| DDR | DDR4,1560M |
| OS | BUILDROOT,kernel-5.10 |
| BL31 | rk3568_bl31_rt_v1.03.elf(optimize RT latency) |
2.1.1 No-load test
2.1.1.1 PREEMPT_RT Patch
rk3568_t:/ # cyclictest -c 0 -m -a -t 4 -p 99
Apolicy: fifo: loadavg: 0.59 0.56 0.98 2/245 2084
T: 0 ( 1976) P:99 I:1000 C:84680446 Min: 0 Act: 0 Avg: 0 Max: 21
T: 1 ( 1977) P:99 I:1500 C:56453626 Min: 0 Act: 0 Avg: 0 Max: 17
T: 2 ( 1978) P:99 I:2000 C:42340216 Min: 0 Act: 0 Avg: 0 Max: 22
T: 3 ( 1979) P:99 I:2500 C:33872169 Min: 0 Act: 1 Avg: 1 Max: 18
Source test duration: 24 hours.
2.1.1.2 Xenomai Cobalt Mode
rk3568_t:/ # /data/cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.29 0.18 0.12 1/1107 4216
T: 0 ( 4021) P:99 I:1000 C:12501264 Min: 1 Act: 8 Avg: 7 Max: 68
T: 1 ( 4022) P:99 I:1500 C:8334176 Min: 2 Act: 8 Avg: 7 Max: 70
T: 2 ( 4023) P:99 I:2000 C:6250631 Min: 2 Act: 9 Avg: 8 Max: 66
T: 3 ( 4024) P:99 I:2500 C:5000505 Min: 2 Act: 6 Avg: 7 Max: 58
Source test duration: 3 hours.
2.1.2 Stress test1
stress-ng -c 4 –io 2 –vm 1 –vm-bytes 4M –timeout 1000000s
2.1.2.1 PREEMPT_RT Patch
rk3568_t:/ # cyclictest -c 0 -m -a -t 4 -p 99
Apolicy: fifo: loadavg: 10.72 10.57 10.54 10/264 3892
T: 0 ( 2023) P:99 I:1000 C:76581100 Min: 0 Act: 2 Avg: 3 Max: 74
T: 1 ( 2024) P:99 I:1500 C:51054043 Min: 0 Act: 2 Avg: 3 Max: 64
T: 2 ( 2025) P:99 I:2000 C:38290514 Min: 0 Act: 4 Avg: 4 Max: 44
T: 3 ( 2026) P:99 I:2500 C:30632399 Min: 0 Act: 2 Avg: 4 Max: 61
Source test duration: 24 hours.
2.1.2.2 Xenomai Cobalt Mode
rk3568_t:/ # /data/cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 7.65 7.80 7.75 8/1118 3998
T: 0 ( 3492) P:99 I:1000 C:21069118 Min: 2 Act: 4 Avg: 13 Max: 85
T: 1 ( 3493) P:99 I:1500 C:14046070 Min: 2 Act: 13 Avg: 15 Max: 76
T: 2 ( 3494) P:99 I:2000 C:10534550 Min: 2 Act: 6 Avg: 16 Max: 70
T: 3 ( 3495) P:99 I:2500 C:8427637 Min: 2 Act: 15 Avg: 15 Max: 96
Source test duration: 5 hours.
2.1.3 Stress test2
stress-ng -c 4 –io 2 –vm 1 –vm-bytes 4M –timeout 1000000s + Fishing Joy game
2.1.3.1 PREEMPT_RT Patch
rk3568_t:/ # cyclictest -c 0 -m -a -t 4 -p 99
policy: fifo: loadavg: 11.92 12.59 12.59 9/1196 3372
T: 0 ( 1389) P:99 I:1000 C:252044459 Min: 0 Act: 6 Avg: 4 Max: 101
T: 1 ( 1390) P:99 I:1500 C:168029630 Min: 0 Act: 3 Avg: 4 Max: 93
T: 2 ( 1391) P:99 I:2000 C:126022214 Min: 0 Act: 1 Avg: 4 Max: 121
T: 3 ( 1392) P:99 I:2500 C:100817765 Min: 0 Act: 6 Avg: 4 Max: 104
Source test duration: 24 hours.
2.1.3.2 Xenomai Cobalt Mode
rk3568_t:/ # /data/cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 10.21 10.06 9.99 10/1193 3177
T: 0 ( 2062) P:99 I:1000 C:41956558 Min: 2 Act: 34 Avg: 20 Max: 112
T: 1 ( 2063) P:99 I:1500 C:27971036 Min: 2 Act: 29 Avg: 20 Max: 128
T: 2 ( 2064) P:99 I:2000 C:20978270 Min: 2 Act: 30 Avg: 18 Max: 82
T: 3 ( 2065) P:99 I:2500 C:16782616 Min: 2 Act: 28 Avg: 18 Max: 105
Source test duration: 12 hours.
2.2 RK3562
| Configuration | Description |
|---|---|
| CPU | 4xA53,2016MHz |
| CACHE | L1-32K,L2-512K |
| DDR | LP4X,1320M |
| OS | BUILDROOT,kernel-5.10 |
2.2.1 No-load test
2.2.1.1 PREEMPT_RT Patch
root@rk3562-buildroot:/# cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 1.00 1.26 1.31 1/202 1344
T: 0 ( 1152) P:99 I:1000 C:51905271 Min: 4 Act: 6 Avg: 6 Max: 46
T: 1 ( 1153) P:99 I:1500 C:34603508 Min: 4 Act: 6 Avg: 6 Max: 55
T: 2 ( 1154) P:99 I:2000 C:25952627 Min: 4 Act: 6 Avg: 6 Max: 28
T: 3 ( 1155) P:99 I:2500 C:20762098 Min: 4 Act: 6 Avg: 6 Max: 55
Source test duration: 14 hours.
2.2.1.2 Xenomai Cobalt Mode
root@rk3562-buildroot:/# cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.02 0.02 0.00 1/152 2459
T: 0 ( 2377) P:99 I:1000 C:14773911 Min: 2 Act: 4 Avg: 4 Max: 31
T: 1 ( 2378) P:99 I:1500 C:9849274 Min: 2 Act: 4 Avg: 4 Max: 28
T: 2 ( 2379) P:99 I:2000 C:7386955 Min: 2 Act: 4 Avg: 4 Max: 18
T: 3 ( 2380) P:99 I:2500 C:5909564 Min: 2 Act: 4 Avg: 4 Max: 32
Source test duration: 4 hours.
2.2.2 Stress test
stress -c 4 –io 2 –vm 1 –vm-bytes 256M –timeout 1000000s
2.2.2.1 PREEMPT_RT Patch
root@rk3562-buildroot:/# cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 9.42 8.33 8.61 9/220 1477
T: 0 ( 1472) P:99 I:1000 C:7971377 Min: 4 Act: 8 Avg: 10 Max: 69
T: 1 ( 1473) P:99 I:1500 C:5314247 Min: 5 Act: 16 Avg: 12 Max: 72
T: 2 ( 1474) P:99 I:2000 C:3985679 Min: 5 Act: 10 Avg: 10 Max: 63
T: 3 ( 1475) P:99 I:2500 C:3188543 Min: 5 Act: 12 Avg: 12 Max: 76
Source test duration: 2 hours.
2.2.2.2 Xenomai Cobalt Mode
root@rk3562-buildroot:/# cyclictest -c 0 -m -n -t 4 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 7.93 7.92 7.92 9/165 2370
T: 0 ( 2266) P:99 I:1000 C:6493284 Min: 2 Act: 11 Avg: 9 Max: 69
T: 1 ( 2267) P:99 I:1500 C:4328849 Min: 2 Act: 12 Avg: 10 Max: 72
T: 2 ( 2268) P:99 I:2000 C:3246637 Min: 2 Act: 11 Avg: 9 Max: 40
T: 3 ( 2269) P:99 I:2500 C:2597305 Min: 2 Act: 13 Avg: 9 Max: 73
Source test duration: 2 hours.
2.3 RK3588
| Configuration | Description |
|---|---|
| CPU | 4xA76(big),2.2GHz,4xA55(little),1.8GHz |
| CACHE | A76:L1-64K,L2-512K A55:L1-32K,L2-128K |
| DDR | LP4X,2112M |
| OS | BUILDROOT,kernel-5.10 |
2.3.1 No-load test
2.3.1.1 PREEMPT_RT Patch
root@rk3588:/# cyclictest -c 0 -m -t 8 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 2.71 3.24 3.29 1/322 3955
T: 0 ( 3406) P:99 I:1000 C:6766462 Min: 3 Act: 4 Avg: 4 Max: 11
T: 1 ( 3407) P:99 I:1500 C:4510976 Min: 4 Act: 4 Avg: 4 Max: 13
T: 2 ( 3408) P:99 I:2000 C:3383228 Min: 4 Act: 4 Avg: 4 Max: 13
T: 3 ( 3409) P:99 I:2500 C:2706579 Min: 4 Act: 4 Avg: 4 Max: 13
T: 4 ( 3410) P:99 I:3000 C:2255481 Min: 1 Act: 1 Avg: 1 Max: 8
T: 5 ( 3411) P:99 I:3500 C:1933267 Min: 1 Act: 1 Avg: 1 Max: 7
T: 6 ( 3412) P:99 I:4000 C:1691609 Min: 1 Act: 1 Avg: 1 Max: 8
T: 7 ( 3413) P:99 I:4500 C:1503652 Min: 1 Act: 1 Avg: 1 Max: 8
Source test duration: 2 hours.
2.3.1.2 Xenomai Cobalt Mode
root@rk3588:/# cyclictest -c 0 -m -n -t 8 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.63 0.60 0.55 1/206 1336
T: 0 ( 1163) P:99 I:1000 C:43237018 Min: 1 Act: 2 Avg: 2 Max: 6
T: 1 ( 1164) P:99 I:1500 C:28824678 Min: 1 Act: 2 Avg: 2 Max: 6
T: 2 ( 1165) P:99 I:2000 C:21618508 Min: 1 Act: 2 Avg: 2 Max: 6
T: 3 ( 1166) P:99 I:2500 C:17294807 Min: 1 Act: 2 Avg: 2 Max: 6
T: 4 ( 1167) P:99 I:3000 C:14412339 Min: 1 Act: 2 Avg: 2 Max: 6
T: 5 ( 1168) P:99 I:3500 C:12353433 Min: 1 Act: 2 Avg: 2 Max: 6
T: 6 ( 1169) P:99 I:4000 C:10809254 Min: 1 Act: 2 Avg: 2 Max: 6
T: 7 ( 1170) P:99 I:4500 C:9608226 Min: 1 Act: 2 Avg: 2 Max: 6
Source test duration: 12 hours.
2.3.2 Stress test
stress-ng -c 8 –io 2 –vm 1 –vm-bytes 1024M –timeout 1000000s
2.3.2.1 PREEMPT_RT Patch
root@rk3588:/# cyclictest -c 0 -m -t 8 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 15.20 15.28 15.29 11/345 10678
T: 0 ( 6379) P:99 I:1000 C:6473077 Min: 3 Act: 13 Avg: 7 Max: 28
T: 1 ( 6380) P:99 I:1500 C:4315388 Min: 4 Act: 7 Avg: 7 Max: 24
T: 2 ( 6381) P:99 I:2000 C:3236536 Min: 3 Act: 4 Avg: 6 Max: 24
T: 3 ( 6382) P:99 I:2500 C:2589231 Min: 4 Act: 8 Avg: 7 Max: 30
T: 4 ( 6383) P:99 I:3000 C:2157683 Min: 1 Act: 1 Avg: 2 Max: 16
T: 5 ( 6384) P:99 I:3500 C:1849443 Min: 1 Act: 2 Avg: 2 Max: 15
T: 6 ( 6385) P:99 I:4000 C:1618261 Min: 1 Act: 2 Avg: 2 Max: 16
T: 7 ( 6386) P:99 I:4500 C:1438455 Min: 1 Act: 2 Avg: 2 Max: 15
Source test duration: 2 hours.
2.3.2.2 Xenomai Cobalt Mode
root@rk3588:/# cyclictest -c 0 -m -n -t 8 -p 99
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 12.82 12.81 12.81 11/225 1490
T: 0 ( 1179) P:99 I:1000 C:12797171 Min: 1 Act: 4 Avg: 4 Max: 19
T: 1 ( 1180) P:99 I:1500 C:8531447 Min: 1 Act: 4 Avg: 3 Max: 16
T: 2 ( 1181) P:99 I:2000 C:6398585 Min: 1 Act: 4 Avg: 4 Max: 25
T: 3 ( 1182) P:99 I:2500 C:5118868 Min: 1 Act: 3 Avg: 5 Max: 28
T: 4 ( 1183) P:99 I:3000 C:4265723 Min: 1 Act: 5 Avg: 4 Max: 17
T: 5 ( 1184) P:99 I:3500 C:3656334 Min: 1 Act: 4 Avg: 5 Max: 18
T: 6 ( 1185) P:99 I:4000 C:3199292 Min: 2 Act: 4 Avg: 5 Max: 17
T: 7 ( 1186) P:99 I:4500 C:2843815 Min: 1 Act: 5 Avg: 5 Max: 19
Source test duration: 4 hours.
2.4 RK3576
| Configuration | Description |
|---|---|
| CPU | 4xA72(big):2.3GHz,4xA53(little):2.2GHz |
| CACHE | A72:L1-I-48K,L1-D-32K,L2-1M A53:L1-I-32K,L1-D-32K,L2-512K |
| DDR | LP4X,2112M |
| OS | BUILDROOT,kernel-6.1 |
2.4.1 No-load test
2.4.1.1 PREEMPT_RT Patch
root@rk3576-buildroot:/# cyclictest -c0 -m -t -p99 -D8H
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 3.50 3.32 3.17 1/309 3491
T: 0 ( 2675) P:99 I:1000 C:28799996 Min: 2 Act: 3 Avg: 3 Max: 34
T: 1 ( 2676) P:99 I:1500 C:19199994 Min: 2 Act: 3 Avg: 3 Max: 25
T: 2 ( 2677) P:99 I:2000 C:14399993 Min: 2 Act: 3 Avg: 3 Max: 27
T: 3 ( 2678) P:99 I:2500 C:11519993 Min: 2 Act: 3 Avg: 3 Max: 28
T: 4 ( 2679) P:99 I:3000 C:9599993 Min: 2 Act: 2 Avg: 2 Max: 17
T: 5 ( 2680) P:99 I:3500 C:8228564 Min: 2 Act: 2 Avg: 2 Max: 19
T: 6 ( 2681) P:99 I:4000 C:7199993 Min: 2 Act: 2 Avg: 2 Max: 16
T: 7 ( 2682) P:99 I:4500 C:6399993 Min: 2 Act: 2 Avg: 2 Max: 16
Source test duration: 8 hours.
2.4.1.2 Xenomai Cobalt Mode
root@rk3576:/# ./usr/demo/cyclictest -c 0 -m -n -t 8 -p 99 -D 2H
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.54 0.54 0.54 1/207 1104
T: 0 ( 1557) P:99 I:1000 C:7199995 Min: 1 Act: 2 Avg: 2 Max: 12
T: 1 ( 1558) P:99 I:1500 C:4799996 Min: 1 Act: 2 Avg: 2 Max: 8
T: 2 ( 1559) P:99 I:2000 C:3599997 Min: 1 Act: 2 Avg: 2 Max: 14
T: 3 ( 1560) P:99 I:2500 C:2879998 Min: 1 Act: 2 Avg: 2 Max: 9
T: 4 ( 1561) P:99 I:3000 C:2399998 Min: 1 Act: 2 Avg: 2 Max: 13
T: 5 ( 1562) P:99 I:3500 C:2057141 Min: 1 Act: 2 Avg: 2 Max: 9
T: 6 ( 1563) P:99 I:4000 C:1799998 Min: 1 Act: 2 Avg: 2 Max: 7
T: 7 ( 1564) P:99 I:4500 C:1599998 Min: 1 Act: 2 Avg: 2 Max: 8
Source test duration: 2 hours.
2.4.2 Stress test
stress-ng -c8 –io 8 –cpu-load 100 -vm 4 –vm-bytes 512M –timeout 10000000s
2.4.2.1 PREEMPT_RT Patch
root@rk3576-buildroot:/# cyclictest -c0 -m -t -p99 -D8H
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 24.41 23.87 23.55 17/341 2533
T: 0 ( 1425) P:99 I:1000 C:28799993 Min: 3 Act: 6 Avg: 9 Max: 44
T: 1 ( 1426) P:99 I:1500 C:19199994 Min: 3 Act: 7 Avg: 9 Max: 36
T: 2 ( 1427) P:99 I:2000 C:14399992 Min: 3 Act: 7 Avg: 8 Max: 35
T: 3 ( 1428) P:99 I:2500 C:11519992 Min: 3 Act: 11 Avg: 10 Max: 39
T: 4 ( 1429) P:99 I:3000 C:9599985 Min: 2 Act: 10 Avg: 8 Max: 41
T: 5 ( 1430) P:99 I:3500 C:8228558 Min: 2 Act: 12 Avg: 7 Max: 35
T: 6 ( 1431) P:99 I:4000 C:7199986 Min: 2 Act: 8 Avg: 9 Max: 48
T: 7 ( 1432) P:99 I:4500 C:6399988 Min: 2 Act: 6 Avg: 7 Max: 38
Source test duration: 8 hours.
2.4.2.2 Xenomai Cobalt Mode
root@rk3576:/# ./usr/demo/cyclictest -c0 -m -n -t -p99 -D 2H
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 21.61 21.60 21.64 20/241 1759
T: 0 ( 1653) P:99 I:1000 C:7199993 Min: 2 Act: 7 Avg: 7 Max: 43
T: 1 ( 1654) P:99 I:1500 C:4799991 Min: 2 Act: 11 Avg: 6 Max: 40
T: 2 ( 1655) P:99 I:2000 C:3599991 Min: 2 Act: 5 Avg: 6 Max: 43
T: 3 ( 1656) P:99 I:2500 C:2879986 Min: 2 Act: 16 Avg: 6 Max: 39
T: 4 ( 1657) P:99 I:3000 C:2399988 Min: 2 Act: 7 Avg: 7 Max: 42
T: 5 ( 1658) P:99 I:3500 C:2057132 Min: 2 Act: 12 Avg: 6 Max: 45
T: 6 ( 1659) P:99 I:4000 C:1799991 Min: 2 Act: 7 Avg: 8 Max: 44
T: 7 ( 1660) P:99 I:4500 C:1599991 Min: 2 Act: 16 Avg: 8 Max: 47
Source test duration: 2 hours.
2.5 RK3506
| Configuration | Description |
|---|---|
| CPU | 3xA7,1512MHz |
| CACHE | L1-16K,L2-128K |
| DDR | DDR3,800M |
| OS | BUILDROOT,kernel-6.1 |
2.5.1 No-load test
2.5.1.1 PREEMPT_RT Patch
root@rk3506-buildroot:/# cyclictest -m -a -p 99 -t 3 -i 1000 -D 2h
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 1.72 1.60 1.48 2/127 4000
T: 0 ( 502) P:99 I:1000 C:7199993 Min: 0 Act: 0 Avg: 1 Max: 14
T: 1 ( 503) P:99 I:1500 C:4799988 Min: 0 Act: 1 Avg: 1 Max: 19
T: 2 ( 504) P:99 I:2000 C:3599985 Min: 0 Act: 2 Avg: 1 Max: 26
Source test duration: 2 hours.
2.5.1.2 Xenomai Cobalt Mode
root@rk3506-buildroot:/# cyclictest -m -a -p 99 -t 3 -i 1000 -D 2h
WARN: stat /dev/cpu_dma_latency failed: No such file or directory
policy: fifo: loadavg: 0.56 0.31 0.21 1/95 2088
T: 0 ( 2356) P:99 I:1000 C:7199998 Min: 4 Act: 4 Avg: 7 Max: 46
T: 1 ( 2357) P:99 I:1500 C:4799998 Min: 4 Act: 12 Avg: 7 Max: 46
T: 2 ( 2358) P:99 I:2000 C:3599997 Min: 3 Act: 5 Avg: 9 Max: 55
Source test duration: 2 hours.
2.5.2 Stress test
stress-ng -c 3 –io 2 –vm 1 –vm-bytes 4M –timeout 1000000s
2.5.2.1 PREEMPT_RT Patch
root@rk3506-buildroot:/# cyclictest -m -a -p 99 -t 3 -i 1000 -D 2h
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 8.49 7.88 7.76 7/137 1083
T: 0 ( 1537) P:99 I:1000 C:7199996 Min: 0 Act: 5 Avg: 4 Max: 71
T: 1 ( 1538) P:99 I:1500 C:4799976 Min: 0 Act: 5 Avg: 4 Max: 115
T: 2 ( 1540) P:99 I:2000 C:3599957 Min: 0 Act: 4 Avg: 4 Max: 129
Source test duration: 2 hours.
2.5.2.2 Xenomai Cobalt Mode
root@rk3506-buildroot:/# cyclictest -m -a -p 99 -t 3 -i 1000 -D 2h
WARN: stat /dev/cpu_dma_latency failed: No such file or directory
policy: fifo: loadavg: 6.87 6.82 6.72 7/104 1531
T: 0 ( 1919) P:99 I:1000 C:7199991 Min: 4 Act: 20 Avg: 26 Max: 124
T: 1 ( 1920) P:99 I:1500 C:4799993 Min: 4 Act: 21 Avg: 28 Max: 155
T: 2 ( 1921) P:99 I:2000 C:3599987 Min: 5 Act: 16 Avg: 28 Max: 133
Source test duration: 2 hours.
2.5.3 Isolated-core test
Isolate CPU1 and apply load on the other two cores: stress-ng -c 3 –io 2 –vm 1 –vm-bytes 4M –timeout 1000000s
2.5.3.1 PREEMPT_RT Patch
root@rk3506-buildroot:/# cyclictest -m -a 1 -p 99 -t 1 -i 1000 --mainaffinity=0 -D 2h
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 7.19 7.17 7.22 7/137 648
T: 0 ( 1117) P:99 I:1000 C:7199996 Min: 0 Act: 2 Avg: 3 Max: 62
Source test duration: 2 hours.
2.5.3.2 Xenomai Cobalt Mode
root@rk3506-buildroot:/# cyclictest -m -a 1 -p 99 -t 1 -i 1000 -D 2h
WARN: stat /dev/cpu_dma_latency failed: No such file or directory
policy: fifo: loadavg: 6.53 6.52 6.57 8/101 1115
T: 0 ( 1503) P:99 I:1000 C:7199992 Min: 4 Act: 15 Avg: 16 Max: 68
Source test duration: 2 hours.