Commit 2394395c authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-mq: don't run the hw_queue from blk_mq_request_bypass_insert 



blk_mq_request_bypass_insert takes a bool parameter to control how to run
the queue at the end of the function.  Move the blk_mq_run_hw_queue call
to the callers that want it instead.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-16-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f0dbe6e8

block/blk-flush.c

+3 −1
Original line number Diff line number Diff line
@@ -389,6 +389,7 @@ void blk_insert_flush(struct request *rq) 
	unsigned long fflags = q->queue_flags;	/* may change, cache */

	unsigned int policy = blk_flush_policy(fflags, rq);

	struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx);

	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;



	/*

	 * @policy now records what operations need to be done.  Adjust
@@ -425,7 +426,8 @@ void blk_insert_flush(struct request *rq) 
	 */

	if ((policy & REQ_FSEQ_DATA) &&

	    !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {

		blk_mq_request_bypass_insert(rq, false, true);

		blk_mq_request_bypass_insert(rq, false);

		blk_mq_run_hw_queue(hctx, false);

		return;

	}

block/blk-mq.c

+11 −13
Original line number Diff line number Diff line
@@ -1442,7 +1442,7 @@ static void blk_mq_requeue_work(struct work_struct *work) 
		if (rq->rq_flags & RQF_DONTPREP) {

			rq->rq_flags &= ~RQF_SOFTBARRIER;

			list_del_init(&rq->queuelist);

			blk_mq_request_bypass_insert(rq, false, false);

			blk_mq_request_bypass_insert(rq, false);

		} else if (rq->rq_flags & RQF_SOFTBARRIER) {

			rq->rq_flags &= ~RQF_SOFTBARRIER;

			list_del_init(&rq->queuelist);
@@ -2457,13 +2457,11 @@ static void blk_mq_run_work_fn(struct work_struct *work) 
 * blk_mq_request_bypass_insert - Insert a request at dispatch list.

 * @rq: Pointer to request to be inserted.

 * @at_head: true if the request should be inserted at the head of the list.

 * @run_queue: If we should run the hardware queue after inserting the request.

 *

 * Should only be used carefully, when the caller knows we want to

 * bypass a potential IO scheduler on the target device.

 */

void blk_mq_request_bypass_insert(struct request *rq, bool at_head,

				  bool run_queue)

void blk_mq_request_bypass_insert(struct request *rq, bool at_head)

{

	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
@@ -2473,9 +2471,6 @@ void blk_mq_request_bypass_insert(struct request *rq, bool at_head, 
	else

		list_add_tail(&rq->queuelist, &hctx->dispatch);

	spin_unlock(&hctx->lock);



	if (run_queue)

		blk_mq_run_hw_queue(hctx, false);

}



static void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx,
@@ -2530,7 +2525,7 @@ static void blk_mq_insert_request(struct request *rq, bool at_head) 
		 * and it is added to the scheduler queue, there is no chance to

		 * dispatch it given we prioritize requests in hctx->dispatch.

		 */

		blk_mq_request_bypass_insert(rq, at_head, false);

		blk_mq_request_bypass_insert(rq, at_head);

	} else if (rq->rq_flags & RQF_FLUSH_SEQ) {

		/*

		 * Firstly normal IO request is inserted to scheduler queue or
@@ -2553,7 +2548,7 @@ static void blk_mq_insert_request(struct request *rq, bool at_head) 
		 * Simply queue flush rq to the front of hctx->dispatch so that

		 * intensive flush workloads can benefit in case of NCQ HW.

		 */

		blk_mq_request_bypass_insert(rq, true, false);

		blk_mq_request_bypass_insert(rq, true);

	} else if (q->elevator) {

		LIST_HEAD(list);
@@ -2673,7 +2668,8 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, 
		break;

	case BLK_STS_RESOURCE:

	case BLK_STS_DEV_RESOURCE:

		blk_mq_request_bypass_insert(rq, false, true);

		blk_mq_request_bypass_insert(rq, false);

		blk_mq_run_hw_queue(hctx, false);

		break;

	default:

		blk_mq_end_request(rq, ret);
@@ -2720,7 +2716,8 @@ static void blk_mq_plug_issue_direct(struct blk_plug *plug) 
			break;

		case BLK_STS_RESOURCE:

		case BLK_STS_DEV_RESOURCE:

			blk_mq_request_bypass_insert(rq, false, true);

			blk_mq_request_bypass_insert(rq, false);

			blk_mq_run_hw_queue(hctx, false);

			goto out;

		default:

			blk_mq_end_request(rq, ret);
@@ -2838,8 +2835,9 @@ static void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 
			break;

		case BLK_STS_RESOURCE:

		case BLK_STS_DEV_RESOURCE:

			blk_mq_request_bypass_insert(rq, false,

						     list_empty(list));

			blk_mq_request_bypass_insert(rq, false);

			if (list_empty(list))

				blk_mq_run_hw_queue(hctx, false);

			goto out;

		default:

			blk_mq_end_request(rq, ret);

block/blk-mq.h

+1 −2
Original line number Diff line number Diff line
@@ -65,8 +65,7 @@ void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set, 
/*

 * Internal helpers for request insertion into sw queues

 */

void blk_mq_request_bypass_insert(struct request *rq, bool at_head,

				  bool run_queue);

void blk_mq_request_bypass_insert(struct request *rq, bool at_head);



/*

 * CPU -> queue mappings