Re: [PATCH] blk-mq: provider helper for setting up an SQ queue and tag set

Ming Lei
2018-10-16T00:58:53Z

On Mon, Oct 15, 2018 at 09:34:36AM -0600, Jens Axboe wrote:
> This pattern is repeated throughout all the blk-mq conversions.
> Provide a basic helper to get it done.
>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> ---
> block/blk-mq.c | 33 +++++++++++++++++++++++++++++++++
> include/linux/blk-mq.h | 4 ++++
> 2 files changed, 37 insertions(+)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index c2ecd64a2403..dcf10e39995a 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2507,6 +2507,39 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
> }
> EXPORT_SYMBOL(blk_mq_init_queue);
>
> +/*
> + * Helper for setting up a queue with mq ops, given queue depth, and
> + * the passed in mq ops flags.
> + */
> +struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set,
> + const struct blk_mq_ops *ops,
> + unsigned int queue_depth,
> + unsigned int set_flags)
> +{
> + struct request_queue *q;
> + int ret;
> +
> + memset(set, 0, sizeof(*set));
> + set->ops = ops;
> + set->nr_hw_queues = 1;
> + set->queue_depth = queue_depth;
> + set->numa_node = NUMA_NO_NODE;
> + set->flags = set_flags;
> +
> + ret = blk_mq_alloc_tag_set(set);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + q = blk_mq_init_queue(set);
> + if (IS_ERR(q)) {
> + blk_mq_free_tag_set(set);
> + return q;
> + }
> +
> + return q;
> +}
> +EXPORT_SYMBOL(blk_mq_init_sq_queue);
> +
> static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set)
> {
> int hw_ctx_size = sizeof(struct blk_mq_hw_ctx);
> diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
> index 1da59c16f637..2286dc12c6bc 100644
> --- a/include/linux/blk-mq.h
> +++ b/include/linux/blk-mq.h
> @@ -203,6 +203,10 @@ enum {
> struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
> struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
> struct request_queue *q);
> +struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set,
> + const struct blk_mq_ops *ops,
> + unsigned int queue_depth,
> + unsigned int set_flags);
> int blk_mq_register_dev(struct device *, struct request_queue *);
> void blk_mq_unregister_dev(struct device *, struct request_queue *);
>
> --
> 2.17.1
>
> --
> Jens Axboe
>

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

--
Ming