Re: [PATCH V5 5/7] blk-mq-sched: move actual dispatching into one helper
From: Christoph Hellwig <hch@infradead.org>
Date: 2017-10-02 14:20:01
Also in:
dm-devel, linux-scsi, lkml
Can you move this to the beginning of your series, just after the other edits to blk_mq_sched_dispatch_requests?
+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.
+{
+ 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);
quoted hunk ↗ jump to hunk
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);
}