bio_vec start offset may be relatively large particularly when large
folio was 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: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Kundan Kumar <kundan.kumar@xxxxxxxxxxx>
---
drivers/nvme/host/pci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 8e0bb9692685..c6408871466f 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -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);
--
2.25.1
