[PATCH 1/3] block: introduce blk_queue_nr_active()

[Ming Lei]

On Mon, Sep 25, 2023 at 12:31:21PM -0400, Ewan D. Milne wrote:
> Returns a count of the total number of active requests
> in a queue.  For non-shared tags (the usual case) this is
> the sum of nr_active from all of the hctxs.

hctx->nr_active is only updated if BLK_MQ_F_TAG_QUEUE_SHARED is true
and blk_mq_is_shared_tags() is false, so hctx->nr_active isn't
available if BLK_MQ_F_TAG_QUEUE_SHARED is false(the usual case?).


Thanks,
Ming