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authorChristoph Hellwig <hch@lst.de>2016-09-14 16:18:53 +0200
committerJens Axboe <axboe@fb.com>2016-09-15 08:42:03 -0600
commitbdd17e75cd97c5c39feee409890a91d0396640fe (patch)
treea7b6b01aa305d466e83255caa08670391c294b33
parent4e68a011428af3211facd932b4003b3fa3ef4faa (diff)
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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: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/blk-mq.c22
-rw-r--r--include/linux/blk-mq.h1
2 files changed, 15 insertions, 8 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ffc9d4a3dbbd..c9499f118ef6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -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;
}
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 60ef14cbcd2d..deda16a9bde4 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -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 */