If CPU_UP_PREPARE fails the perf hotplug code calls perf_event_exit_cpu(), which is a pointless exercise. The cpu is not online, so the smp function calls return -ENXIO. So the result is a list walk to call noops. Remove it. Signed-off-by: Thomas Gleixner --- kernel/events/core.c | 1 - 1 file changed, 1 deletion(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9286,7 +9286,6 @@ perf_cpu_notify(struct notifier_block *s perf_event_init_cpu(cpu); break; - case CPU_UP_CANCELED: case CPU_DOWN_PREPARE: perf_event_exit_cpu(cpu); break;