Commit 8ccdf4a3 authored by Jianchao Wang's avatar Jianchao Wang Committed by Jens Axboe
Browse files

blk-mq: save queue mapping result into ctx directly 



Currently, the queue mapping result is saved in a two-dimensional
array. In the hot path, to get a hctx, we need do following:

  q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]]

This isn't very efficient. We could save the queue mapping result into
ctx directly with different hctx type, like,

  ctx->hctxs[type]

Signed-off-by: default avatarJianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 058fdecc

block/blk-mq-sched.c

+1 −1
Original line number Diff line number Diff line
@@ -321,7 +321,7 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) 
{

	struct elevator_queue *e = q->elevator;

	struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);

	struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx->cpu);

	struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx);

	bool ret = false;

	enum hctx_type type;

block/blk-mq-tag.c

+1 −1
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) 


		data->ctx = blk_mq_get_ctx(data->q);

		data->hctx = blk_mq_map_queue(data->q, data->cmd_flags,

						data->ctx->cpu);

						data->ctx);

		tags = blk_mq_tags_from_data(data);

		if (data->flags & BLK_MQ_REQ_RESERVED)

			bt = &tags->breserved_tags;

block/blk-mq.c

+2 −2
Original line number Diff line number Diff line
@@ -364,7 +364,7 @@ static struct request *blk_mq_get_request(struct request_queue *q, 
	}

	if (likely(!data->hctx))

		data->hctx = blk_mq_map_queue(q, data->cmd_flags,

						data->ctx->cpu);

						data->ctx);

	if (data->cmd_flags & REQ_NOWAIT)

		data->flags |= BLK_MQ_REQ_NOWAIT;
@@ -2435,7 +2435,7 @@ static void blk_mq_map_swqueue(struct request_queue *q) 
				continue;



			hctx = blk_mq_map_queue_type(q, j, i);



			ctx->hctxs[j] = hctx;

			/*

			 * If the CPU is already set in the mask, then we've

			 * mapped this one already. This can happen if

block/blk-mq.h

+4 −3
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ struct blk_mq_ctx { 


	unsigned int		cpu;

	unsigned short		index_hw[HCTX_MAX_TYPES];

	struct blk_mq_hw_ctx 	*hctxs[HCTX_MAX_TYPES];



	/* incremented at dispatch time */

	unsigned long		rq_dispatched[2];
@@ -97,11 +98,11 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue * 
 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue

 * @q: request queue

 * @flags: request command flags

 * @cpu: CPU

 * @cpu: cpu ctx

 */

static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,

						     unsigned int flags,

						     unsigned int cpu)

						     struct blk_mq_ctx *ctx)

{

	enum hctx_type type = HCTX_TYPE_DEFAULT;
@@ -116,7 +117,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, 
		 q->tag_set->map[HCTX_TYPE_READ].nr_queues)

		type = HCTX_TYPE_READ;

	

	return blk_mq_map_queue_type(q, type, cpu);

	return ctx->hctxs[type];

}



/*

block/blk.h

+1 −1
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ extern struct ida blk_queue_ida; 
static inline struct blk_flush_queue *

blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)

{

	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx->cpu)->fq;

	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;

}



static inline void __blk_get_queue(struct request_queue *q)

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