Re: [patch 58/63] futex: Prevent requeue_pi() lock nesting issue on RT

From: Thomas Gleixner
Date: Mon Aug 02 2021 - 10:36:01 EST


On Mon, Aug 02 2021 at 15:10, Peter Zijlstra wrote:

> On Mon, Aug 02, 2021 at 02:56:09PM +0200, Peter Zijlstra wrote:
>> static inline int futex_requeue_pi_wakeup_sync(struct futex_q *q)
>> {
>> + int old, new;
>>
>> + old = atomic_read_acquire(&q->requeue_state);
>> + do {
>> /* Is requeue done already? */
>> + if (old >= Q_REQUEUE_PI_DONE)
>> break;
>
> I think that can be: return old; for slightly simpler code.

Yes.