Migrating tasks to offline CPUs is a pretty big fail, warn about it. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/core.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1173,6 +1173,10 @@ void set_task_cpu(struct task_struct *p, WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || lockdep_is_held(&task_rq(p)->lock))); #endif + /* + * Clearly, migrating tasks to offline CPUs is a fairly daft thing. + */ + WARN_ON_ONCE(!cpu_online(new_cpu)); #endif trace_sched_migrate_task(p, new_cpu);