Re: [RFC][PATCH v2 08/10] smp,irq_work: Use the new irq_work API

[Christoph Hellwig]

On Tue, Aug 18, 2020 at 12:51:10PM +0200, Peter Zijlstra wrote:
>  	if (blk_mq_complete_need_ipi(rq)) {
> -		INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
> -		smp_call_function_single_async(rq->mq_ctx->cpu, &rq->csd);
> +		rq->work = IRQ_WORK_INIT_HARD(__blk_mq_complete_request_remote);
> +		irq_work_queue_remote_static(rq->mq_ctx->cpu, &rq->work);

So given the caller synchronization / use once semantics does it even
make sense to split the init vs call part here?  What about:

		irq_work_queue_remote_static(&rq->work, rq->mq_ctx->cpu,
					    __blk_mq_complete_request_remote);

instead?  And btw, I'm not sure what the "static" stand for.  Maybe
irq_work_queue_remote_once?