[PATCH 5/5] nvme-rdma: support read/write queue separation

[Sagi Grimberg]

Signed-off-by: Sagi Grimberg <s...@grimberg.me>
---
 drivers/nvme/host/rdma.c | 39 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 5057d5ab5aaa..cfe823a491f2 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -645,6 +645,8 @@ static int nvme_rdma_alloc_io_queues(struct nvme_rdma_ctrl 
*ctrl)
        nr_io_queues = min_t(unsigned int, nr_io_queues,
                                ibdev->num_comp_vectors);
 
+       nr_io_queues += min(opts->nr_write_queues, num_online_cpus());
+
        ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
        if (ret)
                return ret;
@@ -714,6 +716,7 @@ static struct blk_mq_tag_set *nvme_rdma_alloc_tagset(struct 
nvme_ctrl *nctrl,
                set->driver_data = ctrl;
                set->nr_hw_queues = nctrl->queue_count - 1;
                set->timeout = NVME_IO_TIMEOUT;
+               set->nr_maps = 2 /* default + read */;
        }
 
        ret = blk_mq_alloc_tag_set(set);
@@ -1750,8 +1753,37 @@ static void nvme_rdma_complete_rq(struct request *rq)
 static int nvme_rdma_map_queues(struct blk_mq_tag_set *set)
 {
        struct nvme_rdma_ctrl *ctrl = set->driver_data;
+       struct blk_mq_queue_map *map;
+       int offset = 0;
+
+       if (ctrl->ctrl.opts->nr_write_queues) {
+               /* separate read/write queues */
+               map = &set->map[HCTX_TYPE_DEFAULT];
+               map->queue_offset = offset;
+               map->nr_queues = ctrl->ctrl.opts->nr_write_queues;
+               blk_mq_rdma_map_queues(map, ctrl->device->dev, 0);
+               offset += map->nr_queues;
+
+               map = &set->map[HCTX_TYPE_READ];
+               map->nr_queues = ctrl->ctrl.opts->nr_io_queues;
+               map->queue_offset = offset;
+               blk_mq_rdma_map_queues(map, ctrl->device->dev, offset);
+               offset += map->nr_queues;
 
-       return blk_mq_rdma_map_queues(&set->map[0], ctrl->device->dev, 0);
+       } else {
+               /* mixed read/write queues */
+               map = &set->map[HCTX_TYPE_DEFAULT];
+               map->queue_offset = 0;
+               map->nr_queues = ctrl->ctrl.opts->nr_io_queues;
+               blk_mq_rdma_map_queues(map, ctrl->device->dev, 0);
+
+               map = &set->map[HCTX_TYPE_READ];
+               map->queue_offset = 0;
+               map->nr_queues = ctrl->ctrl.opts->nr_io_queues;
+               blk_mq_rdma_map_queues(map, ctrl->device->dev, 0);
+       }
+
+       return 0;
 }
 
 static const struct blk_mq_ops nvme_rdma_mq_ops = {
@@ -1906,7 +1938,7 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct 
device *dev,
        INIT_WORK(&ctrl->err_work, nvme_rdma_error_recovery_work);
        INIT_WORK(&ctrl->ctrl.reset_work, nvme_rdma_reset_ctrl_work);
 
-       ctrl->ctrl.queue_count = opts->nr_io_queues + 1; /* +1 for admin queue 
*/
+       ctrl->ctrl.queue_count = opts->nr_io_queues + opts->nr_write_queues + 1;
        ctrl->ctrl.sqsize = opts->queue_size - 1;
        ctrl->ctrl.kato = opts->kato;
 
@@ -1957,7 +1989,8 @@ static struct nvmf_transport_ops nvme_rdma_transport = {
        .module         = THIS_MODULE,
        .required_opts  = NVMF_OPT_TRADDR,
        .allowed_opts   = NVMF_OPT_TRSVCID | NVMF_OPT_RECONNECT_DELAY |
-                         NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO,
+                         NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO |
+                         NVMF_OPT_NR_IO_QUEUES,
        .create_ctrl    = nvme_rdma_create_ctrl,
 };
 
-- 
2.17.1