I have seen this issue for noble:linux-lowlatency 6.8.0-48.48.3 on openstack:cpu2-ram4-disk20 (arm64). (SRU Cycle: 2024.09.30)
I think this test is flaky. To check if "cpuhotplug_do_spin_loop" it uses "ps psr" command where "r" option lists the currently running processes only. Even if a "cpuhotplug_do_spin_loop" process did migrate to target CPU, this does not mean that it is currently running there (as it can be preempted by availability of other tasks). And for architectures with lower number of cpus (in my case 2), test is likely to fail more. Moreover, test doesn't seem to adjust "spin" tasks' priority (I am not sure about this but it doesn't seem to do anything in this regard prior to running the test either). Test needs to either; - run in isolated environment where OS threads run on a dedicated core. - sleep some time (as done currently) and check if the spin process is migrated by the spin process itself. Here is the log: FO: Test start time: Fri Oct 18 20:06:59 UTC 2024 ND: /opt/ltp/bin/ltp-pan -q -e -S -a 166236 -n 166236 -f /tmp/ltp-9srhcvY2Gx/alltests -l /dev/null -C /dev/null -T /dev/null OG File: /dev/null ED COMMAND File: /dev/null NF COMMAND File: /dev/null ng tests....... me: cpuhotplug03 te: Fri Oct 18 20:06:59 UTC 2024 sc: Do tasks get scheduled to a newly on-lined CPU? 08 CPU is 1 ER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND ot 166323 12.8 0.0 2380 1408 ? R 20:06 0:00 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop ot 166324 12.8 0.0 2380 1408 ? R 20:06 0:00 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop ot 166325 12.8 0.0 2380 1408 ? R 20:06 0:00 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop ot 166326 12.8 0.0 2380 1408 ? R 20:06 0:00 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop ot 166331 0.0 0.0 6680 1920 ? S 20:06 0:00 grep cpuhotplug_do_spin_loop 03 1 TINFO: Onlining CPU 1 0 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop 0 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop 0 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop 0 /bin/sh /opt/ltp/testcases/bin/cpuhotplug_do_spin_loop 03 1 TFAIL: No cpuhotplug_do_spin_loop processes found on CPU1 FO: ltp-pan reported some tests FAIL TP Version: 20230929-874-gba610da01 FO: Test end time: Fri Oct 18 20:07:01 UTC 2024 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1931390 Title: cpuhotplug03 in cpuhotplug from ubuntu_ltp failed after successful CPU1 offline To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/1931390/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
