Re: [PATCH v2 3/5] net/mlx5: use buffer address for LKEY search

When searching LKEY, if search key is mempool pointer, the 2nd cacheline
has to be accessed and it even requires to check whether a buffer is
indirect per every search. Instead, using address for search key can reduce
cycles taken. And caching the last hit entry is beneficial as well.

Signed-off-by: Yongseok Koh <redacted>
---
 drivers/net/mlx5/mlx5_mr.c   | 17 ++++++++++++++---
 drivers/net/mlx5/mlx5_rxtx.c | 39 +++++++++++++++++++++------------------
 drivers/net/mlx5/mlx5_rxtx.h |  4 +++-
 drivers/net/mlx5/mlx5_txq.c  |  3 +--
 4 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index 0a3638460..287335179 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c

@@ -265,18 +266,28 @@ txq_mp2mr_iter(struct rte_mempool *mp, void *arg)
 	struct txq_mp2mr_mbuf_check_data data = {
 		.ret = 0,
 	};
+	uintptr_t start;
+	uintptr_t end;
 	unsigned int i;
 
 	/* Register mempool only if the first element looks like a mbuf. */
 	if (rte_mempool_obj_iter(mp, txq_mp2mr_mbuf_check, &data) == 0 ||
 			data.ret == -1)
 		return;
+	if (mlx5_check_mempool(mp, &start, &end) != 0) {
+		ERROR("mempool %p: not virtually contiguous",
+		      (void *)mp);
+		return;
+	}
 	for (i = 0; (i != RTE_DIM(txq_ctrl->txq.mp2mr)); ++i) {
-		if (unlikely(txq_ctrl->txq.mp2mr[i].mp == NULL)) {
+		struct ibv_mr *mr = txq_ctrl->txq.mp2mr[i].mr;
+
+		if (unlikely(mr == NULL)) {
 			/* Unknown MP, add a new MR for it. */
 			break;
 		}
-		if (txq_ctrl->txq.mp2mr[i].mp == mp)
+		if (start >= (uintptr_t)mr->addr &&
+		    end <= (uintptr_t)mr->addr + mr->length)
 			return;
 	}
 	txq_mp2mr_reg(&txq_ctrl->txq, mp, i);