[dpdk-dev] [PATCH v3 4/4] app/testpmd: use per-core variable in flowgen

[Zhihong Wang]

Use per-core variable for flow indexing to solve cache contention in
multi-core scenarios.

Signed-off-by: Zhihong Wang <wangzhihong....@bytedance.com>
---
 app/test-pmd/flowgen.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/app/test-pmd/flowgen.c b/app/test-pmd/flowgen.c
index 229794ee9c..fc9dae4ab3 100644
--- a/app/test-pmd/flowgen.c
+++ b/app/test-pmd/flowgen.c
@@ -51,6 +51,8 @@ static struct rte_ether_addr cfg_ether_src =
 static struct rte_ether_addr cfg_ether_dst =
        {{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x01 }};
 
+RTE_DEFINE_PER_LCORE(int, _next_flow);
+
 #define IP_DEFTTL  64   /* from RFC 1340. */
 
 /*
@@ -80,7 +82,6 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
        uint32_t retry;
        uint64_t tx_offloads;
        uint64_t start_tsc = 0;
-       static int next_flow = 0;
 
        get_start_cycles(&start_tsc);
 
@@ -136,7 +137,7 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
                        ip_hdr->packet_id       = 0;
                        ip_hdr->src_addr        = rte_cpu_to_be_32(cfg_ip_src);
                        ip_hdr->dst_addr        = rte_cpu_to_be_32(cfg_ip_dst +
-                                                                  next_flow);
+                                       RTE_PER_LCORE(_next_flow));
                        ip_hdr->total_length    = RTE_CPU_TO_BE_16(pkt_size -
                                                                   
sizeof(*eth_hdr));
                        ip_hdr->hdr_checksum    = rte_ipv4_cksum(ip_hdr);
@@ -163,7 +164,8 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
                }
                pkts_burst[nb_pkt] = pkt;
 
-               next_flow = (next_flow + 1) % cfg_n_flows;
+               RTE_PER_LCORE(_next_flow) = (RTE_PER_LCORE(_next_flow) + 1) %
+                               cfg_n_flows;
        }
 
        nb_tx = rte_eth_tx_burst(fs->tx_port, fs->tx_queue, pkts_burst, nb_pkt);
@@ -183,9 +185,9 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
        inc_tx_burst_stats(fs, nb_tx);
        if (unlikely(nb_tx < nb_pkt)) {
                /* Back out the flow counter. */
-               next_flow -= (nb_pkt - nb_tx);
-               while (next_flow < 0)
-                       next_flow += cfg_n_flows;
+               RTE_PER_LCORE(_next_flow) -= (nb_pkt - nb_tx);
+               while (RTE_PER_LCORE(_next_flow) < 0)
+                       RTE_PER_LCORE(_next_flow) += cfg_n_flows;
 
                fs->fwd_dropped += nb_pkt - nb_tx;
                do {
-- 
2.11.0