Commit 445874e8 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

blk-mq: pass hctx to blk_mq_dispatch_rq_list 



All requests in the 'list' of blk_mq_dispatch_rq_list belong to same
hctx, so it is better to pass hctx instead of request queue, because
blk-mq's dispatch target is hctx instead of request queue.

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Tested-by: default avatarBaolin Wang <baolin.wang7@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 65c76369

block/blk-mq-sched.c

+6 −8
Original line number Diff line number Diff line
@@ -96,10 +96,9 @@ static int blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) 
	struct elevator_queue *e = q->elevator;

	LIST_HEAD(rq_list);

	int ret = 0;



	do {

	struct request *rq;



	do {

		if (e->type->ops.has_work && !e->type->ops.has_work(hctx))

			break;
@@ -131,7 +130,7 @@ static int blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) 
		 * in blk_mq_dispatch_rq_list().

		 */

		list_add(&rq->queuelist, &rq_list);

	} while (blk_mq_dispatch_rq_list(q, &rq_list, true));

	} while (blk_mq_dispatch_rq_list(rq->mq_hctx, &rq_list, true));



	return ret;

}
@@ -161,10 +160,9 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) 
	LIST_HEAD(rq_list);

	struct blk_mq_ctx *ctx = READ_ONCE(hctx->dispatch_from);

	int ret = 0;



	do {

	struct request *rq;



	do {

		if (!list_empty_careful(&hctx->dispatch)) {

			ret = -EAGAIN;

			break;
@@ -200,7 +198,7 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) 
		/* round robin for fair dispatch */

		ctx = blk_mq_next_ctx(hctx, rq->mq_ctx);



	} while (blk_mq_dispatch_rq_list(q, &rq_list, true));

	} while (blk_mq_dispatch_rq_list(rq->mq_hctx, &rq_list, true));



	WRITE_ONCE(hctx->dispatch_from, ctx);

	return ret;
@@ -240,7 +238,7 @@ static int __blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) 
	 */

	if (!list_empty(&rq_list)) {

		blk_mq_sched_mark_restart_hctx(hctx);

		if (blk_mq_dispatch_rq_list(q, &rq_list, false)) {

		if (blk_mq_dispatch_rq_list(hctx, &rq_list, false)) {

			if (has_sched_dispatch)

				ret = blk_mq_do_dispatch_sched(hctx);

			else
@@ -253,7 +251,7 @@ static int __blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) 
		ret = blk_mq_do_dispatch_ctx(hctx);

	} else {

		blk_mq_flush_busy_ctxs(hctx, &rq_list);

		blk_mq_dispatch_rq_list(q, &rq_list, false);

		blk_mq_dispatch_rq_list(hctx, &rq_list, false);

	}



	return ret;

block/blk-mq.c

+3 −3
Original line number Diff line number Diff line
@@ -1258,10 +1258,10 @@ static void blk_mq_handle_zone_resource(struct request *rq, 
/*

 * Returns true if we did some work AND can potentially do more.

 */

bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,

bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,

			     bool got_budget)

{

	struct blk_mq_hw_ctx *hctx;

	struct request_queue *q = hctx->queue;

	struct request *rq, *nxt;

	bool no_tag = false;

	int errors, queued;
@@ -1283,7 +1283,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, 


		rq = list_first_entry(list, struct request, queuelist);



		hctx = rq->mq_hctx;

		WARN_ON_ONCE(hctx != rq->mq_hctx);

		if (!got_budget && !blk_mq_get_dispatch_budget(q)) {

			blk_mq_put_driver_tag(rq);

			no_budget_avail = true;

block/blk-mq.h

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct blk_mq_ctx { 
void blk_mq_exit_queue(struct request_queue *q);

int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);

void blk_mq_wake_waiters(struct request_queue *q);

bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);

bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *, bool);

void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,

				bool kick_requeue_list);

void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);