[dpdk-dev,1/5] net/mlx5: enable inlining data from multiple segments

Message ID 20171227035547.29571-1-yskoh@mellanox.com (mailing list archive)
State Accepted, archived
Delegated to: Ferruh Yigit
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation fail apply patch file failure

Commit Message

Yongseok Koh Dec. 27, 2017, 3:55 a.m. UTC
  mlx5_tx_burst() doesn't inline data from the 2nd segment. If there's still
enough room in the descriptor after inlining the 1st segment, further
inlining from the 2nd segment would be beneficial to save PCIe bandwidth.

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 44 +++++++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 19 deletions(-)
  

Comments

Shahaf Shuler Dec. 27, 2017, 6:06 a.m. UTC | #1
Wednesday, December 27, 2017 5:56 AM, Yongseok Koh:
> 
> mlx5_tx_burst() doesn't inline data from the 2nd segment. If there's still
> enough room in the descriptor after inlining the 1st segment, further inlining
> from the 2nd segment would be beneficial to save PCIe bandwidth.
> 
> Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5_rxtx.c | 44 +++++++++++++++++++++++++-----------
> --------
>  1 file changed, 25 insertions(+), 19 deletions(-)
> 

Series applied to next-net-mlx, thanks.
  

Patch

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 28c0ad8ab..1e0f5dc52 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -390,7 +390,7 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		if (max_elts < segs_n)
 			break;
 		max_elts -= segs_n;
-		--segs_n;
+		sg = --segs_n;
 		if (unlikely(--max_wqe == 0))
 			break;
 		wqe = (volatile struct mlx5_wqe_v *)
@@ -516,7 +516,7 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		}
 		/* Inline if enough room. */
 		if (max_inline || tso) {
-			uint32_t inl;
+			uint32_t inl = 0;
 			uintptr_t end = (uintptr_t)
 				(((uintptr_t)txq->wqes) +
 				 (1 << txq->wqe_n) * MLX5_WQE_SIZE);
@@ -524,12 +524,14 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 						   RTE_CACHE_LINE_SIZE -
 						   (pkt_inline_sz - 2) -
 						   !!tso * sizeof(inl);
-			uintptr_t addr_end = (addr + inline_room) &
-					     ~(RTE_CACHE_LINE_SIZE - 1);
-			unsigned int copy_b = (addr_end > addr) ?
-				RTE_MIN((addr_end - addr), length) :
-				0;
-
+			uintptr_t addr_end;
+			unsigned int copy_b;
+
+pkt_inline:
+			addr_end = RTE_ALIGN_FLOOR(addr + inline_room,
+						   RTE_CACHE_LINE_SIZE);
+			copy_b = (addr_end > addr) ?
+				 RTE_MIN((addr_end - addr), length) : 0;
 			if (copy_b && ((end - (uintptr_t)raw) > copy_b)) {
 				/*
 				 * One Dseg remains in the current WQE.  To
@@ -541,7 +543,7 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 				if (unlikely(max_wqe < n))
 					break;
 				max_wqe -= n;
-				if (tso) {
+				if (tso && !inl) {
 					inl = rte_cpu_to_be_32(copy_b |
 							       MLX5_INLINE_SEG);
 					rte_memcpy((void *)raw,
@@ -576,11 +578,18 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			} else if (!segs_n) {
 				goto next_pkt;
 			} else {
-				/* dseg will be advance as part of next_seg */
-				dseg = (volatile rte_v128u32_t *)
-					((uintptr_t)wqe +
-					 ((ds - 1) * MLX5_WQE_DWORD_SIZE));
-				goto next_seg;
+				raw += copy_b;
+				inline_room -= copy_b;
+				--segs_n;
+				buf = buf->next;
+				assert(buf);
+				addr = rte_pktmbuf_mtod(buf, uintptr_t);
+				length = DATA_LEN(buf);
+#ifdef MLX5_PMD_SOFT_COUNTERS
+				total_length += length;
+#endif
+				(*txq->elts)[++elts_head & elts_m] = buf;
+				goto pkt_inline;
 			}
 		} else {
 			/*
@@ -639,12 +648,8 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			addr >> 32,
 		};
 		(*txq->elts)[++elts_head & elts_m] = buf;
-		++sg;
-		/* Advance counter only if all segs are successfully posted. */
-		if (sg < segs_n)
+		if (--segs_n)
 			goto next_seg;
-		else
-			j += sg;
 next_pkt:
 		if (ds > MLX5_DSEG_MAX) {
 			txq->stats.oerrors++;
@@ -653,6 +658,7 @@  mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		++elts_head;
 		++pkts;
 		++i;
+		j += sg;
 		/* Initialize known and common part of the WQE structure. */
 		if (tso) {
 			wqe->ctrl = (rte_v128u32_t){