[dpdk-dev] [PATCH v1] app/testpmd: optimized MAC swap by using neon intrinsics
Ruifeng Wang
ruifeng.wang at arm.com
Mon Mar 11 09:14:25 CET 2019
Improved MAC swap performance for ARM platform.
The improvement was achieved by using neon intrinsics
to save CPU cycles and doing swap for four packets
at a time.
The optimization had 15% - 20% throughput boost
in testpmd MAC swap mode.
Signed-off-by: Ruifeng Wang <ruifeng.wang at arm.com>
Reviewed-by: Gavin Hu <gavin.hu at arm.com>
Reviewed-by: Phil Yang <phil.yang at arm.com>
---
app/test-pmd/macswap.c | 4 +-
app/test-pmd/macswap_neon.h | 93 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 96 insertions(+), 1 deletion(-)
create mode 100644 app/test-pmd/macswap_neon.h
diff --git a/app/test-pmd/macswap.c b/app/test-pmd/macswap.c
index cbb41b7..71af916 100644
--- a/app/test-pmd/macswap.c
+++ b/app/test-pmd/macswap.c
@@ -66,8 +66,10 @@
#include <rte_flow.h>
#include "testpmd.h"
-#ifdef RTE_ARCH_X86
+#if defined(RTE_ARCH_X86)
#include "macswap_sse.h"
+#elif defined(RTE_MACHINE_CPUFLAG_NEON)
+#include "macswap_neon.h"
#else
#include "macswap.h"
#endif
diff --git a/app/test-pmd/macswap_neon.h b/app/test-pmd/macswap_neon.h
new file mode 100644
index 0000000..bad1b9b
--- /dev/null
+++ b/app/test-pmd/macswap_neon.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2019 Arm Limited
+ */
+
+#ifndef _MACSWAP_NEON_H_
+#define _MACSWAP_NEON_H_
+
+#include "macswap_common.h"
+#include "rte_vect.h"
+
+static inline void
+do_macswap(struct rte_mbuf *pkts[], uint16_t nb,
+ struct rte_port *txp)
+{
+ struct ether_hdr *eth_hdr[4];
+ struct rte_mbuf *mb[4];
+ uint64_t ol_flags;
+ int i;
+ int r;
+ uint8x16_t v0, v1, v2, v3;
+ /**
+ * Index map be used to shuffle the 16 bytes.
+ * byte 0-5 will be swapped with byte 6-11.
+ * byte 12-15 will keep unchanged.
+ */
+ uint8x16_t idx_map = {6, 7, 8, 9, 10, 11, 0, 1, 2, 3, 4, 5,
+ 12, 13, 14, 15};
+
+ ol_flags = ol_flags_init(txp->dev_conf.txmode.offloads);
+ vlan_qinq_set(pkts, nb, ol_flags,
+ txp->tx_vlan_id, txp->tx_vlan_id_outer);
+
+ i = 0;
+ r = nb;
+
+ while (r >= 4) {
+ if (r >= 8) {
+ rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 4], void *));
+ rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 5], void *));
+ rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 6], void *));
+ rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 7], void *));
+ }
+
+ mb[0] = pkts[i++];
+ eth_hdr[0] = rte_pktmbuf_mtod(mb[0], struct ether_hdr *);
+
+ mb[1] = pkts[i++];
+ eth_hdr[1] = rte_pktmbuf_mtod(mb[1], struct ether_hdr *);
+
+ mb[2] = pkts[i++];
+ eth_hdr[2] = rte_pktmbuf_mtod(mb[2], struct ether_hdr *);
+
+ mb[3] = pkts[i++];
+ eth_hdr[3] = rte_pktmbuf_mtod(mb[3], struct ether_hdr *);
+
+ v0 = vld1q_u8((uint8_t const *)eth_hdr[0]);
+ v1 = vld1q_u8((uint8_t const *)eth_hdr[1]);
+ v2 = vld1q_u8((uint8_t const *)eth_hdr[2]);
+ v3 = vld1q_u8((uint8_t const *)eth_hdr[3]);
+
+ v0 = vqtbl1q_u8(v0, idx_map);
+ v1 = vqtbl1q_u8(v1, idx_map);
+ v2 = vqtbl1q_u8(v2, idx_map);
+ v3 = vqtbl1q_u8(v3, idx_map);
+
+ vst1q_u8((uint8_t *)eth_hdr[0], v0);
+ vst1q_u8((uint8_t *)eth_hdr[1], v1);
+ vst1q_u8((uint8_t *)eth_hdr[2], v2);
+ vst1q_u8((uint8_t *)eth_hdr[3], v3);
+
+ mbuf_field_set(mb[0], ol_flags);
+ mbuf_field_set(mb[1], ol_flags);
+ mbuf_field_set(mb[2], ol_flags);
+ mbuf_field_set(mb[3], ol_flags);
+ r -= 4;
+ }
+
+ for ( ; i < nb; i++) {
+ if (i < nb - 1)
+ rte_prefetch0(rte_pktmbuf_mtod(pkts[i+1], void *));
+ mb[0] = pkts[i];
+ eth_hdr[0] = rte_pktmbuf_mtod(mb[0], struct ether_hdr *);
+
+ /* Swap dest and src mac addresses. */
+ v0 = vld1q_u8((uint8_t const *)eth_hdr[0]);
+ v0 = vqtbl1q_u8(v0, idx_map);
+ vst1q_u8((uint8_t *)eth_hdr[0], v0);
+
+ mbuf_field_set(mb[0], ol_flags);
+ }
+}
+
+#endif /* _MACSWAP_NEON_H_ */
--
2.7.4
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