On 12/02, Oleg Nesterov wrote: > > The lockless while_each_thread() is racy and broken, almost > every user can loop forever. > ... > Another problem with while_each_thread() is that it is very easy > to use it wrongly, and oom_kill.c is the good example.
Forgot to mention, it is not necessarily safe even under task list lock if it is used wrongly. Again, oom_kill.c is the good example, oom_kill_process() does read_lock(&tasklist_lock) but it doesn't verify that p is still alive. The new for_each_thread() is much simpler in this respect, it only needs the stable task_struct. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
