Re: [PATCH 3/3] blk-mq: prealloc tags when increase tagset nr_hw_queues

[Ming Lei]

On Mon, Aug 21, 2023 at 05:56:02PM +0800, chengming.zhou@xxxxxxxxx wrote:
> From: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
> 
> Just like blk_mq_alloc_tag_set(), it's better to prepare all tags before
> using to map to queue ctxs in blk_mq_map_swqueue(), which now have to
> consider empty set->tags[].
> 
> The good point is that we can fallback easily if increasing nr_hw_queues
> fail, instead of just mapping to hctx[0] when fail in blk_mq_map_swqueue().
> 
> And the fallback path already has tags free & clean handling, so all
> is good.
> 
> Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>

Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>

-- 
Ming