[dpdk-dev] [PATCH 14/14] net/dpaa2: prefetch the parse results from next fd

Hemant Agrawal hemant.agrawal at nxp.com
Fri Dec 8 06:21:27 CET 2017


From: Nipun Gupta <nipun.gupta at nxp.com>

As there were less number of cpu cycles in between when we access
the parse results and when we prefetch them, this patch modifies
the prefetch of the next parse result.

Signed-off-by: Nipun Gupta <nipun.gupta at nxp.com>
---
 drivers/net/dpaa2/dpaa2_rxtx.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dpaa2/dpaa2_rxtx.c b/drivers/net/dpaa2/dpaa2_rxtx.c
index e8edc67..9b66bd3 100644
--- a/drivers/net/dpaa2/dpaa2_rxtx.c
+++ b/drivers/net/dpaa2/dpaa2_rxtx.c
@@ -526,7 +526,7 @@ dpaa2_dev_prefetch_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	int ret, num_rx = 0;
 	uint8_t is_last = 0, status;
 	struct qbman_swp *swp;
-	const struct qbman_fd *fd[DPAA2_DQRR_RING_SIZE];
+	const struct qbman_fd *fd[DPAA2_DQRR_RING_SIZE], *next_fd;
 	struct qbman_pull_desc pulldesc;
 	struct queue_storage_info_t *q_storage = dpaa2_q->q_storage;
 	struct rte_eth_dev *dev = dpaa2_q->dev;
@@ -569,6 +569,7 @@ dpaa2_dev_prefetch_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		set_swp_active_dqs(DPAA2_PER_LCORE_DPIO->index, dq_storage);
 	}
 	dq_storage = q_storage->active_dqs;
+	rte_prefetch0((void *)((uint64_t)(dq_storage + 1)));
 	/* Check if the previous issued command is completed.
 	 * Also seems like the SWP is shared between the Ethernet Driver
 	 * and the SEC driver.
@@ -583,7 +584,7 @@ dpaa2_dev_prefetch_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		 */
 		while (!qbman_check_new_result(dq_storage))
 			;
-		rte_prefetch0((void *)((uint64_t)(dq_storage + 1)));
+		rte_prefetch0((void *)((uint64_t)(dq_storage + 2)));
 		/* Check whether Last Pull command is Expired and
 		 * setting Condition for Loop termination
 		 */
@@ -596,8 +597,9 @@ dpaa2_dev_prefetch_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		}
 		fd[num_rx] = qbman_result_DQ_fd(dq_storage);
 
+		next_fd = qbman_result_DQ_fd(dq_storage + 1);
 		/* Prefetch Annotation address for the parse results */
-		rte_prefetch0((void *)((uint64_t)DPAA2_GET_FD_ADDR(fd[num_rx])
+		rte_prefetch0((void *)((uint64_t)DPAA2_GET_FD_ADDR(next_fd)
 				+ DPAA2_FD_PTA_SIZE + 16));
 
 		if (unlikely(DPAA2_FD_GET_FORMAT(fd[num_rx]) == qbman_fd_sg))
-- 
2.7.4



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