Re: [PATCH 11/13] nvme: switch to use pci_alloc_irq_vectors

[Sagi Grimberg]

On 14/09/16 07:18, Christoph Hellwig wrote:
> Use the new helper to automatically select the right interrupt type, as
> well as to use the automatic interupt affinity assignment.

Patch title and the change description are a little short IMO to
describe what is going on here (need the blk-mq side too).

I'd also think it would be better to split this to 2 patches but
really not a must...

> +static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
> +{
> +	struct nvme_dev *dev = set->driver_data;
> +
> +	return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev));
> +}
> +

Question: is using pci_alloc_irq_vectors() obligated for
supplying blk-mq with the device affinity mask?

If I do this completely-untested [1] what will happen?

[1]:
--
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 8d2875b4c56d..76693d406efe 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1518,6 +1518,14 @@ static void nvme_rdma_complete_rq(struct request *rq)
        blk_mq_end_request(rq, error);
 }

+static int nvme_rdma_map_queues(struct blk_mq_tag_set *set)
+{
+       struct nvme_rdma_ctrl *ctrl = set->driver_data;
+       struct device *dev = ctrl->device->dev.dma_device;
+
+       return blk_mq_pci_map_queues(set, to_pci_dev(dev));
+}
+
 static struct blk_mq_ops nvme_rdma_mq_ops = {
        .queue_rq       = nvme_rdma_queue_rq,
        .complete       = nvme_rdma_complete_rq,
@@ -1528,6 +1536,7 @@ static struct blk_mq_ops nvme_rdma_mq_ops = {
        .init_hctx      = nvme_rdma_init_hctx,
        .poll           = nvme_rdma_poll,
        .timeout        = nvme_rdma_timeout,
+       .map_queues     = nvme_rdma_map_queues,
 };

 static struct blk_mq_ops nvme_rdma_admin_mq_ops = {
--