Commit bdd17e75 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-mq: only allocate a single mq_map per tag_set 



The mapping is identical for all queues in a tag_set, so stop wasting
memory for building multiple.  Note that for now I've kept the mq_map
pointer in the request_queue, but we'll need to investigate if we can
remove it without suffering too much from the additional pointer chasing.
The same would apply to the mq_ops pointer as well.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 4e68a011

block/blk-mq.c

+14 −8
Original line number Diff line number Diff line
@@ -1973,7 +1973,6 @@ void blk_mq_release(struct request_queue *q) 
		kfree(hctx);

	}



	kfree(q->mq_map);

	q->mq_map = NULL;



	kfree(q->queue_hw_ctx);
@@ -2072,9 +2071,7 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, 
	if (!q->queue_hw_ctx)

		goto err_percpu;



	q->mq_map = blk_mq_make_queue_map(set);

	if (!q->mq_map)

		goto err_map;

	q->mq_map = set->mq_map;



	blk_mq_realloc_hw_ctxs(set, q);

	if (!q->nr_hw_queues)
@@ -2124,8 +2121,6 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, 
	return q;



err_hctxs:

	kfree(q->mq_map);

err_map:

	kfree(q->queue_hw_ctx);

err_percpu:

	free_percpu(q->queue_ctx);
@@ -2347,14 +2342,22 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) 
	if (!set->tags)

		return -ENOMEM;



	set->mq_map = blk_mq_make_queue_map(set);

	if (!set->mq_map)

		goto out_free_tags;



	if (blk_mq_alloc_rq_maps(set))

		goto enomem;

		goto out_free_mq_map;



	mutex_init(&set->tag_list_lock);

	INIT_LIST_HEAD(&set->tag_list);



	return 0;

enomem:



out_free_mq_map:

	kfree(set->mq_map);

	set->mq_map = NULL;

out_free_tags:

	kfree(set->tags);

	set->tags = NULL;

	return -ENOMEM;
@@ -2370,6 +2373,9 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) 
			blk_mq_free_rq_map(set, set->tags[i], i);

	}



	kfree(set->mq_map);

	set->mq_map = NULL;



	kfree(set->tags);

	set->tags = NULL;

}

include/linux/blk-mq.h

+1 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ struct blk_mq_hw_ctx { 
};



struct blk_mq_tag_set {

	unsigned int		*mq_map;

	struct blk_mq_ops	*ops;

	unsigned int		nr_hw_queues;

	unsigned int		queue_depth;	/* max hw supported */

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