Re: [ANNOUNCE] v5.14-rc4-rt4

[Sebastian Andrzej Siewior]

On 2021-08-04 12:17:04 [-0400], Steven Rostedt wrote:
> Perhaps in this situation, we could open code it to:
> 
>   	if (stall_hash != -1U) {
> 		raw_spin_unlock(&wqe->lock);
> 
> 		/* On RT the spin_lock_irq() does not disable interrupts */
> 		if (IS_ENABLED(CONFIG_PREEMPT_RT))
> 			local_irq_enable();

no preemption happens here with NEED_RESCHED set.

>  		io_wait_on_hash(wqe, stall_hash);
> 
> 		if (IS_ENABLED(CONFIG_PREEMPT_RT))
> 			local_irq_disable();
> 		raw_spin_lock(&wqe->lock);
>  	}
> 
> Note, I haven't looked at the rest of the code to know the ripple
> effect of this, but I'm just suggesting the idea.
> 

Sebastian