iser-target: Avoid using FRMR for single dma entry requests

This patch changes isert_reg_rdma_frwr() to not use FRMR for single
dma entry requests from small I/Os, in order to avoid the associated
memory registration overhead.

Using DMA MR is sufficient here for the single dma entry requests,
and addresses a >= v3.12 performance regression.

Signed-off-by: Vu Pham <[email protected]>
Cc: <[email protected]> # v3.12+
Signed-off-by: Nicholas Bellinger <[email protected]>
1 file changed