[PATCH 16/16] nvme-multipath: enable polled I/O
From: Christoph Hellwig <hch@lst.de>
Date: 2021-06-15 13:16:14
Also in:
linux-fsdevel, linux-nvme
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
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@lst.de> Tested-by: Mark Wunderlich <redacted> --- 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 f77b774699de..48ea649d6c24 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c@@ -450,6 +450,15 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) blk_queue_flag_set(QUEUE_FLAG_NONROT, head->disk->queue); blk_queue_flag_set(QUEUE_FLAG_NOWAIT, head->disk->queue); + /* + * 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, head->disk->queue); /* set to a default value of 512 until the disk is validated */ blk_queue_logical_block_size(head->disk->queue, 512);
--
2.30.2