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* [PATCH v2 1/2] nvme-rdma: fix queue mapping when queue count is limited
@ 2019-05-29  5:49 Sagi Grimberg
  2019-05-29  5:49 ` [PATCH v2 2/2] nvme-tcp: " Sagi Grimberg
                   ` (3 more replies)
  0 siblings, 4 replies; 11+ messages in thread
From: Sagi Grimberg @ 2019-05-29  5:49 UTC (permalink / raw)


When the controller supports less queues than requested, we
should make sure that queue mapping does the right thing and
not assume that all queues are available. This fixes a crash
when the controller supports less queues than requested.

The rules are:
1. if no write/poll queues are requested, we assign the available queues
   to the default queue map. The default and read queue maps share the
   existing queues.
2. if write queues are requested:
  - first make sure that read queue map gets the requested
    nr_io_queues count
  - then grant the default queue map the minimum between the requested
    nr_write_queues and the remaining queues. If there are no available
    queues to dedicate to the default queue map, fallback to (1) and
    share all the queues in the existing queue map.
3. if poll queues are requested:
  - map the remaining queues to the poll queue map.

Also, provide a log indication on how we constructed the different
queue maps.

Reported-by: Harris, James R <james.r.harris at intel.com>
Cc: <stable at vger.kernel.org> # v5.0+
Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
---
Changes from v1:
- keep the num_comp_vectors upper limit on number of io queues
- keep the queue sets sizes in local variables for readability

 drivers/nvme/host/rdma.c | 99 +++++++++++++++++++++++++---------------
 1 file changed, 61 insertions(+), 38 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index f383146e7d0f..26709a2ab593 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -641,34 +641,16 @@ static int nvme_rdma_alloc_io_queues(struct nvme_rdma_ctrl *ctrl)
 {
 	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 	struct ib_device *ibdev = ctrl->device->dev;
-	unsigned int nr_io_queues;
+	unsigned int nr_io_queues, nr_default_queues;
+	unsigned int nr_read_queues, nr_poll_queues;
 	int i, ret;
 
-	nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
-
-	/*
-	 * we map queues according to the device irq vectors for
-	 * optimal locality so we don't need more queues than
-	 * completion vectors.
-	 */
-	nr_io_queues = min_t(unsigned int, nr_io_queues,
-				ibdev->num_comp_vectors);
-
-	if (opts->nr_write_queues) {
-		ctrl->io_queues[HCTX_TYPE_DEFAULT] =
-				min(opts->nr_write_queues, nr_io_queues);
-		nr_io_queues += ctrl->io_queues[HCTX_TYPE_DEFAULT];
-	} else {
-		ctrl->io_queues[HCTX_TYPE_DEFAULT] = nr_io_queues;
-	}
-
-	ctrl->io_queues[HCTX_TYPE_READ] = nr_io_queues;
-
-	if (opts->nr_poll_queues) {
-		ctrl->io_queues[HCTX_TYPE_POLL] =
-			min(opts->nr_poll_queues, num_online_cpus());
-		nr_io_queues += ctrl->io_queues[HCTX_TYPE_POLL];
-	}
+	nr_read_queues = min_t(unsigned int, ibdev->num_comp_vectors,
+				min(opts->nr_io_queues, num_online_cpus()));
+	nr_default_queues =  min_t(unsigned int, ibdev->num_comp_vectors,
+				min(opts->nr_write_queues, num_online_cpus()));
+	nr_poll_queues = min(opts->nr_poll_queues, num_online_cpus());
+	nr_io_queues = nr_read_queues + nr_default_queues + nr_poll_queues;
 
 	ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
 	if (ret)
@@ -681,6 +663,34 @@ static int nvme_rdma_alloc_io_queues(struct nvme_rdma_ctrl *ctrl)
 	dev_info(ctrl->ctrl.device,
 		"creating %d I/O queues.\n", nr_io_queues);
 
+	if (opts->nr_write_queues && nr_read_queues < nr_io_queues) {
+		/*
+		 * separate read/write queues
+		 * hand out dedicated default queues only after we have
+		 * sufficient read queues.
+		 */
+		ctrl->io_queues[HCTX_TYPE_READ] = nr_read_queues;
+		nr_io_queues -= ctrl->io_queues[HCTX_TYPE_READ];
+		ctrl->io_queues[HCTX_TYPE_DEFAULT] =
+			min(nr_default_queues, nr_io_queues);
+		nr_io_queues -= ctrl->io_queues[HCTX_TYPE_DEFAULT];
+	} else {
+		/*
+		 * shared read/write queues
+		 * either no write queues were requested, or we don't have
+		 * sufficient queue count to have dedicated default queues.
+		 */
+		ctrl->io_queues[HCTX_TYPE_DEFAULT] =
+			min(nr_read_queues, nr_io_queues);
+		nr_io_queues -= ctrl->io_queues[HCTX_TYPE_DEFAULT];
+	}
+
+	if (opts->nr_poll_queues && nr_io_queues) {
+		/* map dedicated poll queues only if we have queues left */
+		ctrl->io_queues[HCTX_TYPE_POLL] =
+			min(nr_poll_queues, nr_io_queues);
+	}
+
 	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
 		ret = nvme_rdma_alloc_queue(ctrl, i,
 				ctrl->ctrl.sqsize + 1);
@@ -1763,17 +1773,24 @@ 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 nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 
-	set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
-	set->map[HCTX_TYPE_DEFAULT].nr_queues =
-			ctrl->io_queues[HCTX_TYPE_DEFAULT];
-	set->map[HCTX_TYPE_READ].nr_queues = ctrl->io_queues[HCTX_TYPE_READ];
-	if (ctrl->ctrl.opts->nr_write_queues) {
+	if (opts->nr_write_queues && ctrl->io_queues[HCTX_TYPE_READ]) {
 		/* separate read/write queues */
+		set->map[HCTX_TYPE_DEFAULT].nr_queues =
+			ctrl->io_queues[HCTX_TYPE_DEFAULT];
+		set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
+		set->map[HCTX_TYPE_READ].nr_queues =
+			ctrl->io_queues[HCTX_TYPE_READ];
 		set->map[HCTX_TYPE_READ].queue_offset =
-				ctrl->io_queues[HCTX_TYPE_DEFAULT];
+			ctrl->io_queues[HCTX_TYPE_DEFAULT];
 	} else {
-		/* mixed read/write queues */
+		/* shared read/write queues */
+		set->map[HCTX_TYPE_DEFAULT].nr_queues =
+			ctrl->io_queues[HCTX_TYPE_DEFAULT];
+		set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
+		set->map[HCTX_TYPE_READ].nr_queues =
+			ctrl->io_queues[HCTX_TYPE_DEFAULT];
 		set->map[HCTX_TYPE_READ].queue_offset = 0;
 	}
 	blk_mq_rdma_map_queues(&set->map[HCTX_TYPE_DEFAULT],
@@ -1781,16 +1798,22 @@ static int nvme_rdma_map_queues(struct blk_mq_tag_set *set)
 	blk_mq_rdma_map_queues(&set->map[HCTX_TYPE_READ],
 			ctrl->device->dev, 0);
 
-	if (ctrl->ctrl.opts->nr_poll_queues) {
+	if (opts->nr_poll_queues && ctrl->io_queues[HCTX_TYPE_POLL]) {
+		/* map dedicated poll queues only if we have queues left */
 		set->map[HCTX_TYPE_POLL].nr_queues =
 				ctrl->io_queues[HCTX_TYPE_POLL];
 		set->map[HCTX_TYPE_POLL].queue_offset =
-				ctrl->io_queues[HCTX_TYPE_DEFAULT];
-		if (ctrl->ctrl.opts->nr_write_queues)
-			set->map[HCTX_TYPE_POLL].queue_offset +=
-				ctrl->io_queues[HCTX_TYPE_READ];
+			ctrl->io_queues[HCTX_TYPE_DEFAULT] +
+			ctrl->io_queues[HCTX_TYPE_READ];
 		blk_mq_map_queues(&set->map[HCTX_TYPE_POLL]);
 	}
+
+	dev_info(ctrl->ctrl.device,
+		"mapped %d/%d/%d default/read/poll queues.\n",
+		ctrl->io_queues[HCTX_TYPE_DEFAULT],
+		ctrl->io_queues[HCTX_TYPE_READ],
+		ctrl->io_queues[HCTX_TYPE_POLL]);
+
 	return 0;
 }
 
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2019-06-01  8:59 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-05-29  5:49 [PATCH v2 1/2] nvme-rdma: fix queue mapping when queue count is limited Sagi Grimberg
2019-05-29  5:49 ` [PATCH v2 2/2] nvme-tcp: " Sagi Grimberg
2019-05-29 15:55   ` Harris, James R
2019-06-01  8:58   ` Christoph Hellwig
2019-05-29 15:50 ` [PATCH v2 1/2] nvme-rdma: " Max Gurtovoy
2019-05-29 17:58   ` Sagi Grimberg
2019-05-29 20:27     ` Sagi Grimberg
2019-05-29 22:22     ` Max Gurtovoy
2019-05-29 22:41       ` Sagi Grimberg
2019-05-29 15:55 ` Harris, James R
2019-06-01  8:59 ` Christoph Hellwig

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