On 03/14, Peter Zijlstra wrote: > > Do we want a WARN_ON_ONCE(atomic_read(&tsk->usage)); in free_task()? > Because in the above scenario we're freeing it with references on.
Not sure, in this case copy_process() should decrement tsk->usage before free_task(), note the atomic_set(&tsk->usage, 2) in dup_task_struct(). Perhaps we should just add WARN_ON(tsk->usage != 2) into copy_process() right before free_task() ? On the other hand, WARN_ON(atomic_read(&tsk->usage)) looks pointless, the only caller is put_task_struct(). Oleg.
