On Mon, Oct 02, 2017 at 07:19:56AM -0700, Christoph Hellwig wrote:
> Can you move this to the beginning of your series, just after
> the other edits to blk_mq_sched_dispatch_requests?
OK.
>
> > +static void blk_mq_do_dispatch_sched(struct request_queue *q,
> > + struct elevator_queue *e,
> > + struct blk_mq_hw_ctx *hctx)
>
> No need to pass anything but the hctx here, the other two can
> be trivially derived from it.
OK.
>
> > +{
> > + LIST_HEAD(rq_list);
> > +
> > + do {
> > + struct request *rq;
> > +
> > + rq = e->type->ops.mq.dispatch_request(hctx);
>
> how about shortening this to:
>
> struct request *rq = e->type->ops.mq.dispatch_request(hctx);
OK
>
> > void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
> > {
> > struct request_queue *q = hctx->queue;
> > @@ -136,16 +152,8 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
> > * on the dispatch list or we were able to dispatch from the
> > * dispatch list.
> > */
> > - if (do_sched_dispatch && has_sched_dispatch) {
> > - do {
> > - struct request *rq;
> > -
> > - rq = e->type->ops.mq.dispatch_request(hctx);
> > - if (!rq)
> > - break;
> > - list_add(&rq->queuelist, &rq_list);
> > - } while (blk_mq_dispatch_rq_list(q, &rq_list));
> > - }
> > + if (do_sched_dispatch && has_sched_dispatch)
> > + blk_mq_do_dispatch_sched(q, e, hctx);
> > }
>
> Please use this new helper to simplify the logic. E.g.:
>
> if (!list_empty(&rq_list)) {
> blk_mq_sched_mark_restart_hctx(hctx);
> if (blk_mq_dispatch_rq_list(q, &rq_list) && has_sched_dispatch)
> blk_mq_do_dispatch_sched(hctx);
> } else if (has_sched_dispatch) {
> blk_mq_do_dispatch_sched(hctx);
> } else {
> blk_mq_flush_busy_ctxs(hctx, &rq_list);
> blk_mq_dispatch_rq_list(q, &rq_list);
> }
OK
--
Ming
