This change has been tested and shows improvement in latencies with cyclictest, even with an untuned system. Jammy 5.15: 1066 (PREEMPT_DEBUG enabled): 17:18:55 INFO | START rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721755135 localtime=Jul 23 17:18:55 17:18:55 DEBUG| Persistent state client._record_indent now set to 2 17:18:55 DEBUG| Persistent state client.unexpected_reboot now set to ('rt_tests_cyclictest.rt_tests_cyclictest', 'rt_tests_cyclictest.rt_tests_cyclictest') 17:18:55 WARNI| System python is too old, crash handling disabled 17:18:55 DEBUG| Running '/home/ubuntu/autotest/client/tmp/rt_tests_cyclictest/src/rt-tests/cyclictest -t 10 -m -l 100000 -p 80 -i 200 -d 0 -b 200' 17:18:55 DEBUG| [stdout] # /dev/cpu_dma_latency set to 0us 17:18:55 DEBUG| [stdout] policy: fifo: loadavg: 14.85 3.71 1.35 1/772 3846 17:19:15 DEBUG| [stdout] 17:19:15 DEBUG| [stdout] T: 0 ( 3837) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 22 17:19:15 DEBUG| [stdout] T: 1 ( 3838) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 11 17:19:15 DEBUG| [stdout] T: 2 ( 3839) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 19 17:19:15 DEBUG| [stdout] T: 3 ( 3840) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 22 17:19:15 DEBUG| [stdout] T: 4 ( 3841) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 47 17:19:15 DEBUG| [stdout] T: 5 ( 3842) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 20 17:19:15 DEBUG| [stdout] T: 6 ( 3843) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 8 17:19:15 DEBUG| [stdout] T: 7 ( 3844) P:80 I:200 C: 99995 Min: 2 Act: 2 Avg: 2 Max: 55 17:19:15 DEBUG| [stdout] T: 8 ( 3845) P:80 I:200 C: 99993 Min: 2 Act: 2 Avg: 2 Max: 18 17:19:15 DEBUG| [stdout] T: 9 ( 3846) P:80 I:200 C: 99984 Min: 2 Act: 2 Avg: 2 Max: 15 17:19:15 DEBUG| [stdout] # Thread Ids: 03837 03838 03839 03840 03841 03842 03843 03844 03845 03846 17:19:15 INFO | GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721755155 localtime=Jul 23 17:19:15 completed successfully 17:19:15 INFO | END GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721755155 localtime=Jul 23 17:19:15 17:19:15 DEBUG| Persistent state client._record_indent now set to 1 17:19:15 DEBUG| Persistent state client.unexpected_reboot deleted 17:19:15 INFO | END GOOD ---- ---- timestamp=1721755155 localtime=Jul 23 17:19:15 17:19:15 DEBUG| Persistent state client._record_indent now set to 0 17:19:15 INFO | Report successfully generated at /home/ubuntu/autotest/client/results/default/job_report.html 1068 (PREEMPT_DEBUG disabled): 12:52:04 INFO | START rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721825524 localtime=Jul 24 12:52:04 12:52:04 DEBUG| Persistent state client._record_indent now set to 2 12:52:04 DEBUG| Persistent state client.unexpected_reboot now set to ('rt_tests_cyclictest.rt_tests_cyclictest', 'rt_tests_cyclictest.rt_tests_cyclictest') 12:52:04 WARNI| System python is too old, crash handling disabled 12:52:04 DEBUG| Running '/home/ubuntu/autotest/client/tmp/rt_tests_cyclictest/src/rt-tests/cyclictest -t 10 -m -l 100000 -p 80 -i 200 -d 0 -b 200' 12:52:04 DEBUG| [stdout] # /dev/cpu_dma_latency set to 0us 12:52:04 DEBUG| [stdout] policy: fifo: loadavg: 16.43 8.21 4.22 1/779 2607 12:52:24 DEBUG| [stdout] 12:52:24 DEBUG| [stdout] T: 0 ( 2598) P:80 I:200 C: 100000 Min: 1 Act: 2 Avg: 1 Max: 12 12:52:24 DEBUG| [stdout] T: 1 ( 2599) P:80 I:200 C: 99998 Min: 1 Act: 2 Avg: 1 Max: 15 12:52:24 DEBUG| [stdout] T: 2 ( 2600) P:80 I:200 C: 99996 Min: 1 Act: 2 Avg: 1 Max: 13 12:52:24 DEBUG| [stdout] T: 3 ( 2601) P:80 I:200 C: 99986 Min: 1 Act: 1 Avg: 1 Max: 11 12:52:24 DEBUG| [stdout] T: 4 ( 2602) P:80 I:200 C: 99984 Min: 1 Act: 2 Avg: 2 Max: 19 12:52:24 DEBUG| [stdout] T: 5 ( 2603) P:80 I:200 C: 99973 Min: 1 Act: 2 Avg: 1 Max: 9 12:52:24 DEBUG| [stdout] T: 6 ( 2604) P:80 I:200 C: 99972 Min: 1 Act: 2 Avg: 2 Max: 13 12:52:24 DEBUG| [stdout] T: 7 ( 2605) P:80 I:200 C: 99961 Min: 1 Act: 2 Avg: 2 Max: 36 12:52:24 DEBUG| [stdout] T: 8 ( 2606) P:80 I:200 C: 99959 Min: 1 Act: 2 Avg: 2 Max: 23 12:52:24 DEBUG| [stdout] T: 9 ( 2607) P:80 I:200 C: 99954 Min: 1 Act: 2 Avg: 2 Max: 19 12:52:24 DEBUG| [stdout] # Thread Ids: 02598 02599 02600 02601 02602 02603 02604 02605 02606 02607 12:52:24 INFO | GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721825544 localtime=Jul 24 12:52:24 completed successfully 12:52:24 INFO | END GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721825544 localtime=Jul 24 12:52:24 12:52:24 DEBUG| Persistent state client._record_indent now set to 1 12:52:24 DEBUG| Persistent state client.unexpected_reboot deleted 12:52:24 INFO | END GOOD ---- ---- timestamp=1721825544 localtime=Jul 24 12:52:24 12:52:24 DEBUG| Persistent state client._record_indent now set to 0 12:52:24 INFO | Report successfully generated at /home/ubuntu/autotest/client/results/default/job_report.html Noble 6.8 1004 (PREEMPT_DEBUG enabled): 14:49:31 INFO | START rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721832571 localtime=Jul 24 14:49:31 14:49:31 DEBUG| Persistent state client._record_indent now set to 2 14:49:31 DEBUG| Persistent state client.unexpected_reboot now set to ('rt_tests_cyclictest.rt_tests_cyclictest', 'rt_tests_cyclictest.rt_tests_cyclictest') 14:49:31 WARNI| System python is too old, crash handling disabled 14:49:31 DEBUG| Running '/home/ubuntu/autotest/client/tmp/rt_tests_cyclictest/src/rt-tests/cyclictest -t 10 -m -l 100000 -p 80 -i 200 -d 0 -b 200' 14:49:32 DEBUG| [stdout] # /dev/cpu_dma_latency set to 0us 14:49:32 DEBUG| [stdout] policy: fifo: loadavg: 1.14 0.53 0.20 1/913 3456 14:49:52 DEBUG| [stdout] 14:49:52 DEBUG| [stdout] T: 0 ( 3447) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 23 14:49:52 DEBUG| [stdout] T: 1 ( 3448) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 23 14:49:52 DEBUG| [stdout] T: 2 ( 3449) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 17 14:49:52 DEBUG| [stdout] T: 3 ( 3450) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 23 14:49:52 DEBUG| [stdout] T: 4 ( 3451) P:80 I:200 C: 100000 Min: 2 Act: 3 Avg: 2 Max: 38 14:49:52 DEBUG| [stdout] T: 5 ( 3452) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 20 14:49:52 DEBUG| [stdout] T: 6 ( 3453) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 93 14:49:52 DEBUG| [stdout] T: 7 ( 3454) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 47 14:49:52 DEBUG| [stdout] T: 8 ( 3455) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 20 14:49:52 DEBUG| [stdout] T: 9 ( 3456) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 61 14:49:52 DEBUG| [stdout] # Thread Ids: 03447 03448 03449 03450 03451 03452 03453 03454 03455 03456 14:49:52 INFO | GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721832592 localtime=Jul 24 14:49:52 completed successfully 14:49:52 INFO | END GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721832592 localtime=Jul 24 14:49:52 14:49:52 DEBUG| Persistent state client._record_indent now set to 1 14:49:52 DEBUG| Persistent state client.unexpected_reboot deleted 14:49:52 INFO | END GOOD ---- ---- timestamp=1721832592 localtime=Jul 24 14:49:52 14:49:52 DEBUG| Persistent state client._record_indent now set to 0 14:49:52 INFO | Report successfully generated at /home/ubuntu/autotest/client/results/default/job_report.html 1006 (PREEMPT_DEBUG disabled): 14:09:38 INFO | START rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721830178 localtime=Jul 24 14:09:38 14:09:38 DEBUG| Persistent state client._record_indent now set to 2 14:09:38 DEBUG| Persistent state client.unexpected_reboot now set to ('rt_tests_cyclictest.rt_tests_cyclictest', 'rt_tests_cyclictest.rt_tests_cyclictest') 14:09:38 WARNI| System python is too old, crash handling disabled 14:09:38 DEBUG| Running '/home/ubuntu/autotest/client/tmp/rt_tests_cyclictest/src/rt-tests/cyclictest -t 10 -m -l 100000 -p 80 -i 200 -d 0 -b 200' 14:09:38 DEBUG| [stdout] # /dev/cpu_dma_latency set to 0us 14:09:38 DEBUG| [stdout] policy: fifo: loadavg: 0.68 0.61 0.28 1/867 3308 14:09:58 DEBUG| [stdout] 14:09:58 DEBUG| [stdout] T: 0 ( 3299) P:80 I:200 C: 100000 Min: 1 Act: 2 Avg: 2 Max: 22 14:09:58 DEBUG| [stdout] T: 1 ( 3300) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 15 14:09:58 DEBUG| [stdout] T: 2 ( 3301) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 25 14:09:58 DEBUG| [stdout] T: 3 ( 3302) P:80 I:200 C: 100000 Min: 1 Act: 2 Avg: 2 Max: 17 14:09:58 DEBUG| [stdout] T: 4 ( 3303) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 12 14:09:58 DEBUG| [stdout] T: 5 ( 3304) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 10 14:09:58 DEBUG| [stdout] T: 6 ( 3305) P:80 I:200 C: 100000 Min: 1 Act: 2 Avg: 2 Max: 19 14:09:58 DEBUG| [stdout] T: 7 ( 3306) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 11 14:09:58 DEBUG| [stdout] T: 8 ( 3307) P:80 I:200 C: 100000 Min: 2 Act: 2 Avg: 2 Max: 8 14:09:58 DEBUG| [stdout] T: 9 ( 3308) P:80 I:200 C: 100000 Min: 1 Act: 1 Avg: 2 Max: 11 14:09:58 DEBUG| [stdout] # Thread Ids: 03299 03300 03301 03302 03303 03304 03305 03306 03307 03308 14:09:58 INFO | GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721830198 localtime=Jul 24 14:09:58 completed successfully 14:09:58 INFO | END GOOD rt_tests_cyclictest.rt_tests_cyclictest rt_tests_cyclictest.rt_tests_cyclictest timestamp=1721830198 localtime=Jul 24 14:09:58 14:09:58 DEBUG| Persistent state client._record_indent now set to 1 14:09:58 DEBUG| Persistent state client.unexpected_reboot deleted 14:09:58 INFO | END GOOD ---- ---- timestamp=1721830198 localtime=Jul 24 14:09:58 14:09:58 DEBUG| Persistent state client._record_indent now set to 0 14:09:58 INFO | Report successfully generated at /home/ubuntu/autotest/client/results/default/job_report.html