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>
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 60ef14c..deda16a 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -67,6 +67,7 @@
};
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 */