Set the poll queue flag to enable polling, given that the multipath node just dispatches the bios to a lower queue. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- drivers/nvme/host/multipath.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 516fe977606d..e95b93655d06 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -446,6 +446,15 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) goto out; blk_queue_flag_set(QUEUE_FLAG_NONROT, q); blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q); + /* + * This assumes all controllers that refer to a namespace either + * support poll queues or not. That is not a strict guarantee, + * but if the assumption is wrong the effect is only suboptimal + * performance but not correctness problem. + */ + if (ctrl->tagset->nr_maps > HCTX_TYPE_POLL && + ctrl->tagset->map[HCTX_TYPE_POLL].nr_queues) + blk_queue_flag_set(QUEUE_FLAG_POLL, q);
If one controller does not support polling and the other does, won't the block layer fail to map a queue for REQ_POLLED requests? Maybe clear in the else case here?
