handle_exit_race && PF_EXITING

[Thomas Gleixner]

On Wed, 6 Nov 2019, Oleg Nesterov wrote:
> 
> I think that (with or without this fix) handle_exit_race() logic needs
> cleanups, there is no reason for get_futex_value_locked(), we can drop
> ->pi_lock right after we see PF_EXITPIDONE. Lets discuss this later.

Which still is in atomic because the hash bucket lock is held, ergo
get_futex_value_locked() needs to stay for now.

So the only thing we could do is to reduce the pi_lock held section a bit.

Thanks,

	tglx