------- Comment From [email protected] 2026-10-07 14:02 EDT------- Verification performed on b46lp08:
- Machine: IBM Type 9175 (z17), LPAR - OS: Ubuntu 24.04.5 LTS (Noble), s390x - Kernel tested: 6.8.0-147-generic (from noble-proposed) - Previous kernel: 6.8.0-146-generic (noble-updates) - Bug: LP#2165732 / LTC BZ#222376 - Upstream fix: 337bd95507a16063687cfc286ea90de5cca48c37 "s390/cpumf: Install CPU hotplug handler" Test method: Reproduced the scenario from the bug description on a real LPAR (systemd-detect-virt: none). CPU hotplug add was triggered during an active perf stat session: echo 0 > /sys/devices/system/cpu/cpu1/online perf stat -e cycles -i -- stress-ng -t 10s --matrix 1 & sleep 1 echo 1 > /sys/devices/system/cpu/cpu1/online wait Result: PASS The kernel did not panic. perf stat completed cleanly with exit code 0. No oops, no BUG, no call trace in dmesg. cpu1 came back online without issue. perf reported valid counter data: 108,712,706 cycles 10.023970280 seconds time elapsed Verified (multiple times). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2165732 Title: [UBUNTU 24.04] kernel: CPU hotplug unsupported by CPUMF To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/2165732/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
