** Tags added: 6.8 sru-s20240708 -- You received this bug notification because you are a member of Canonical Platform QA Team, which is subscribed to ubuntu-kernel-tests. https://bugs.launchpad.net/bugs/2073526
Title: timers:posix_timers in ubuntu_kernel_selftests fails on Noble Status in ubuntu-kernel-tests: New Bug description: The timers:posix_timers selftests are failing consistently in multiple cloud kernels (including noble:linux-azure and jammy:linux-azure-6.8, jammy:linux-aws-6.8) running on small instances: DEBUG| Running 'make run_tests -C timers TEST_PROGS=posix_timers TEST_GEN_PROGS='' TEST_CUSTOM_PROGS=''' DEBUG| [stdout] make: Entering directory '/home/azure/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/timers' DEBUG| [stdout] TAP version 13 DEBUG| [stdout] 1..1 DEBUG| [stdout] # timeout set to 0 DEBUG| [stdout] # selftests: timers: posix_timers DEBUG| [stdout] # TAP version 13 DEBUG| [stdout] # 1..6 DEBUG| [stdout] # # Testing posix timers. False negative may happen on CPU execution DEBUG| [stdout] # # based timers if other threads run on the CPU... DEBUG| [stdout] # Diff too high: 3904813..not ok 1 ITIMER_VIRTUAL DEBUG| [stdout] # Diff too high: 4025856..not ok 2 ITIMER_PROF DEBUG| [stdout] # ok 3 ITIMER_REAL DEBUG| [stdout] # ok 4 timer_create() per thread DEBUG| [stdout] # ok 5 timer_create() per process DEBUG| [stdout] # ok 6 check signal distribution DEBUG| [stdout] # # Totals: pass:4 fail:2 xfail:0 xpass:0 skip:0 error:0 This has been spotted before (LP: #1851805, LP: #1849095), but I believe the tests were flaky due to jitter (they fail if the diff value > 2500000us); this time the tests seem to fail consistently on 6.8 kernels with the diff value being always close to 4000000us (seems too high to be due to jitter). I verified they fail consistently (after several runs) on noble:linux-azure running on a Standard_A2_v2 Azure instance, while passing consistently on jammy:linux-azure on the same instance flavor. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/2073526/+subscriptions -- Mailing list: https://launchpad.net/~canonical-ubuntu-qa Post to : canonical-ubuntu-qa@lists.launchpad.net Unsubscribe : https://launchpad.net/~canonical-ubuntu-qa More help : https://help.launchpad.net/ListHelp
