Re: [PATCH v3 07/13] futex: Throughput-optimized (TP) futexes

[Thomas Gleixner]

On Fri, 30 Sep 2016, Waiman Long wrote:
> +	WRITE_ONCE(state->owner, current);
> +	preempt_disable();
> +	for (;;) {
> +		ret = futex_trylock(uaddr, vpid, &uval, true);

Did you actually read what I said? You CANNOT access userspace in a preempt
disabled region without disabling pagefaults and handle the resulting
wreckage yourself.

End of review.

       tglx