[PATCH 2/3] nvme: add polling options for loop target
Sagi Grimberg
sagi at grimberg.me
Wed Mar 22 00:44:54 PDT 2023
On 3/22/23 02:23, Keith Busch wrote:
> From: Keith Busch <kbusch at kernel.org>
>
> This is for mostly for testing purposes.
>
> Signed-off-by: Keith Busch <kbusch at kernel.org>
> ---
> drivers/nvme/target/loop.c | 63 +++++++++++++++++++++++++++++++++++---
> 1 file changed, 58 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
> index f2d24b2d992f8..0587ead60b09e 100644
> --- a/drivers/nvme/target/loop.c
> +++ b/drivers/nvme/target/loop.c
> @@ -22,6 +22,7 @@ struct nvme_loop_iod {
> struct nvmet_req req;
> struct nvme_loop_queue *queue;
> struct work_struct work;
> + struct work_struct poll;
> struct sg_table sg_table;
> struct scatterlist first_sgl[];
> };
> @@ -37,6 +38,7 @@ struct nvme_loop_ctrl {
> struct nvme_ctrl ctrl;
>
> struct nvmet_port *port;
> + u32 io_queues[HCTX_MAX_TYPES];
> };
>
> static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
> @@ -76,7 +78,11 @@ static void nvme_loop_complete_rq(struct request *req)
> struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
>
> sg_free_table_chained(&iod->sg_table, NVME_INLINE_SG_CNT);
> - nvme_complete_rq(req);
> +
> + if (req->mq_hctx->type != HCTX_TYPE_POLL || !in_interrupt())
> + nvme_complete_rq(req);
> + else
> + queue_work(nvmet_wq, &iod->poll);
> }
>
> static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
> @@ -120,6 +126,15 @@ static void nvme_loop_queue_response(struct nvmet_req *req)
> }
> }
>
> +static void nvme_loop_poll_work(struct work_struct *work)
> +{
> + struct nvme_loop_iod *iod =
> + container_of(work, struct nvme_loop_iod, poll);
> + struct request *req = blk_mq_rq_from_pdu(iod);
> +
> + nvme_complete_rq(req);
> +}
> +
> static void nvme_loop_execute_work(struct work_struct *work)
> {
> struct nvme_loop_iod *iod =
> @@ -170,6 +185,30 @@ static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
> return BLK_STS_OK;
> }
>
> +static bool nvme_loop_poll_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
> +{
> + struct blk_mq_hw_ctx *hctx = data;
> + struct nvme_loop_iod *iod;
> + struct request *rq;
> +
> + rq = blk_mq_tag_to_rq(hctx->tags, bitnr);
> + if (!rq)
> + return true;
> +
> + iod = blk_mq_rq_to_pdu(rq);
> + flush_work(&iod->poll);
If we want to go down this route, I would think that maybe
it'd be better to add .poll to nvmet_req like .execute, that can
actually be wired to bio_poll ? for file it can be wired to fop.iopoll
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