Commit 1bd293fc authored by Kundan Kumar's avatar Kundan Kumar Committed by Keith Busch
Browse files

nvme: adjust multiples of NVME_CTRL_PAGE_SIZE in offset 



bio_vec start offset may be relatively large particularly when large
folio gets added to the bio. A bigger offset will result in avoiding the
single-segment mapping optimization and end up using expensive
mempool_alloc further.

Rather than using absolute value, adjust bv_offset by
NVME_CTRL_PAGE_SIZE while checking if segment can be fitted into one/two
PRP entries.

Suggested-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKundan Kumar <kundan.kumar@samsung.com>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 64e3d02b

drivers/nvme/host/pci.c

+2 −1
Original line number Diff line number Diff line
@@ -778,7 +778,8 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, 
		struct bio_vec bv = req_bvec(req);



		if (!is_pci_p2pdma_page(bv.bv_page)) {

			if (bv.bv_offset + bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2)

			if ((bv.bv_offset & (NVME_CTRL_PAGE_SIZE - 1)) +

			     bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2)

				return nvme_setup_prp_simple(dev, req,

							     &cmnd->rw, &bv);