Re: [RFC 5/7] mm: introduce external memory hinting API

[Oleg Nesterov]

On 05/27, Minchan Kim wrote:
>
> > another problem is that pid_task(pid) can return a zombie leader, in this case
> > mm_access() will fail while it shouldn't.
>
> I'm sorry. I didn't notice that. However, I couldn't understand your point.
> Why do you think mm_access shouldn't fail even though pid_task returns
> a zombie leader?

The leader can exit (call sys_exit(), not sys_exit_group()), this won't affect
other threads. In this case the process is still alive even if the leader thread
is zombie. That is why we have find_lock_task_mm().

Oleg.