[PATCH] examples/l3fwd: add option to set RX burst size

[Jie Hai <haijie1@huawei.com>]

Now the Rx burst size is fixed to MAX_PKT_BURST (32). This
parameter needs to be modified in some performance optimization
scenarios. So an option '--burst' is added to set the burst size
explicitly. The default value is DEFAULT_PKT_BURST (32) and maximum
value is MAX_PKT_BURST (512).

Signed-off-by: Jie Hai <haijie1@huawei.com>
---
 examples/l3fwd/l3fwd.h     |  5 +++-
 examples/l3fwd/l3fwd_acl.c |  2 +-
 examples/l3fwd/l3fwd_em.c  |  2 +-
 examples/l3fwd/l3fwd_fib.c |  2 +-
 examples/l3fwd/l3fwd_lpm.c |  2 +-
 examples/l3fwd/main.c      | 58 ++++++++++++++++++++++++++++++++++++--
 6 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/examples/l3fwd/l3fwd.h b/examples/l3fwd/l3fwd.h
index 93ce652d02b7..3ebee6301295 100644
--- a/examples/l3fwd/l3fwd.h
+++ b/examples/l3fwd/l3fwd.h
@@ -23,7 +23,8 @@
 #define RX_DESC_DEFAULT 1024
 #define TX_DESC_DEFAULT 1024
 
-#define MAX_PKT_BURST     32
+#define DEFAULT_PKT_BURST 32
+#define MAX_PKT_BURST 512
 #define BURST_TX_DRAIN_US 100 /* TX drain every ~100us */
 
 #define MEMPOOL_CACHE_SIZE 256
@@ -115,6 +116,8 @@ extern struct acl_algorithms acl_alg[];
 
 extern uint32_t max_pkt_len;
 
+extern uint32_t nb_pkt_per_burst;
+
 /* Send burst of packets on an output interface */
 static inline int
 send_burst(struct lcore_conf *qconf, uint16_t n, uint16_t port)
diff --git a/examples/l3fwd/l3fwd_acl.c b/examples/l3fwd/l3fwd_acl.c
index b635011ef708..ccb9946837ed 100644
--- a/examples/l3fwd/l3fwd_acl.c
+++ b/examples/l3fwd/l3fwd_acl.c
@@ -1119,7 +1119,7 @@ acl_main_loop(__rte_unused void *dummy)
 			portid = qconf->rx_queue_list[i].port_id;
 			queueid = qconf->rx_queue_list[i].queue_id;
 			nb_rx = rte_eth_rx_burst(portid, queueid,
-				pkts_burst, MAX_PKT_BURST);
+				pkts_burst, nb_pkt_per_burst);
 
 			if (nb_rx > 0) {
 				acl_process_pkts(pkts_burst, hops, nb_rx,
diff --git a/examples/l3fwd/l3fwd_em.c b/examples/l3fwd/l3fwd_em.c
index 31a7e05e39d0..da9c45e3a482 100644
--- a/examples/l3fwd/l3fwd_em.c
+++ b/examples/l3fwd/l3fwd_em.c
@@ -644,7 +644,7 @@ em_main_loop(__rte_unused void *dummy)
 			portid = qconf->rx_queue_list[i].port_id;
 			queueid = qconf->rx_queue_list[i].queue_id;
 			nb_rx = rte_eth_rx_burst(portid, queueid, pkts_burst,
-				MAX_PKT_BURST);
+				nb_pkt_per_burst);
 			if (nb_rx == 0)
 				continue;
 
diff --git a/examples/l3fwd/l3fwd_fib.c b/examples/l3fwd/l3fwd_fib.c
index f38b19af3f57..aa81b12fe7dc 100644
--- a/examples/l3fwd/l3fwd_fib.c
+++ b/examples/l3fwd/l3fwd_fib.c
@@ -239,7 +239,7 @@ fib_main_loop(__rte_unused void *dummy)
 			portid = qconf->rx_queue_list[i].port_id;
 			queueid = qconf->rx_queue_list[i].queue_id;
 			nb_rx = rte_eth_rx_burst(portid, queueid, pkts_burst,
-					MAX_PKT_BURST);
+					nb_pkt_per_burst);
 			if (nb_rx == 0)
 				continue;
 
diff --git a/examples/l3fwd/l3fwd_lpm.c b/examples/l3fwd/l3fwd_lpm.c
index e8fd95aae9ce..048c02491378 100644
--- a/examples/l3fwd/l3fwd_lpm.c
+++ b/examples/l3fwd/l3fwd_lpm.c
@@ -205,7 +205,7 @@ lpm_main_loop(__rte_unused void *dummy)
 			portid = qconf->rx_queue_list[i].port_id;
 			queueid = qconf->rx_queue_list[i].queue_id;
 			nb_rx = rte_eth_rx_burst(portid, queueid, pkts_burst,
-				MAX_PKT_BURST);
+				nb_pkt_per_burst);
 			if (nb_rx == 0)
 				continue;
 
diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 01b763e5ba11..ba0a7f7088f0 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -55,6 +55,7 @@
 
 uint16_t nb_rxd = RX_DESC_DEFAULT;
 uint16_t nb_txd = TX_DESC_DEFAULT;
+uint32_t nb_pkt_per_burst = DEFAULT_PKT_BURST;
 
 /**< Ports set in promiscuous mode off by default. */
 static int promiscuous_on;
@@ -395,6 +396,7 @@ print_usage(const char *prgname)
 		" --config (port,queue,lcore)[,(port,queue,lcore)]"
 		" [--rx-queue-size NPKTS]"
 		" [--tx-queue-size NPKTS]"
+		" [--burst NPKTS]"
 		" [--eth-dest=X,MM:MM:MM:MM:MM:MM]"
 		" [--max-pkt-len PKTLEN]"
 		" [--no-numa]"
@@ -420,6 +422,8 @@ print_usage(const char *prgname)
 		"            Default: %d\n"
 		"  --tx-queue-size NPKTS: Tx queue size in decimal\n"
 		"            Default: %d\n"
+		"  --burst NPKTS: Burst size in decimal\n"
+		"            Default: %d\n"
 		"  --eth-dest=X,MM:MM:MM:MM:MM:MM: Ethernet destination for port X\n"
 		"  --max-pkt-len PKTLEN: maximum packet length in decimal (64-9600)\n"
 		"  --no-numa: Disable numa awareness\n"
@@ -449,7 +453,7 @@ print_usage(const char *prgname)
 		"                    another is route entry at while line leads with character '%c'.\n"
 		"  --rule_ipv6=FILE: Specify the ipv6 rules entries file.\n"
 		"  --alg: ACL classify method to use, one of: %s.\n\n",
-		prgname, RX_DESC_DEFAULT, TX_DESC_DEFAULT,
+		prgname, RX_DESC_DEFAULT, TX_DESC_DEFAULT, DEFAULT_PKT_BURST,
 		ACL_LEAD_CHAR, ROUTE_LEAD_CHAR, alg);
 }
 
@@ -667,6 +671,49 @@ parse_lookup(const char *optarg)
 	return 0;
 }
 
+static void
+parse_pkt_burst(const char *optarg)
+{
+	struct rte_eth_dev_info dev_info;
+	uint16_t burst_size;
+	uint16_t pkt_burst;
+	char *end = NULL;
+	int ret;
+
+	/* parse decimal string */
+	pkt_burst = strtoul(optarg, &end, 10);
+	if ((optarg[0] == '\0') || (end == NULL) || (*end != '\0'))
+		return;
+
+	if (pkt_burst > MAX_PKT_BURST) {
+		RTE_LOG(INFO, L3FWD, "User provided burst must be <= %d. Using default value %d\n",
+			MAX_PKT_BURST, nb_pkt_per_burst);
+		return;
+	} else if (pkt_burst > 0) {
+		nb_pkt_per_burst = pkt_burst;
+		return;
+	}
+
+	/* If user gives a value of zero, query the PMD for its recommended Rx burst size. */
+	ret = rte_eth_dev_info_get(0, &dev_info);
+	if (ret != 0)
+		return;
+	burst_size = dev_info.default_rxportconf.burst_size;
+	if (burst_size == 0) {
+		RTE_LOG(INFO, L3FWD, "PMD does not recommend a burst size. Using default value %d. "
+			"User provided value must be in [1, %d]\n",
+			nb_pkt_per_burst, MAX_PKT_BURST);
+		return;
+	} else if (burst_size > MAX_PKT_BURST) {
+		RTE_LOG(INFO, L3FWD, "PMD recommended burst size %d exceeds maximum value %d. "
+			"Using default value %d\n",
+			burst_size, MAX_PKT_BURST, nb_pkt_per_burst);
+		return;
+	}
+	nb_pkt_per_burst = burst_size;
+	RTE_LOG(INFO, L3FWD, "Using PMD-provided burst value %d\n", burst_size);
+}
+
 #define MAX_JUMBO_PKT_LEN  9600
 
 static const char short_options[] =
@@ -698,6 +745,7 @@ static const char short_options[] =
 #define CMD_LINE_OPT_RULE_IPV4 "rule_ipv4"
 #define CMD_LINE_OPT_RULE_IPV6 "rule_ipv6"
 #define CMD_LINE_OPT_ALG "alg"
+#define CMD_LINE_OPT_PKT_BURST "burst"
 
 enum {
 	/* long options mapped to a short option */
@@ -726,7 +774,8 @@ enum {
 	CMD_LINE_OPT_LOOKUP_NUM,
 	CMD_LINE_OPT_ENABLE_VECTOR_NUM,
 	CMD_LINE_OPT_VECTOR_SIZE_NUM,
-	CMD_LINE_OPT_VECTOR_TMO_NS_NUM
+	CMD_LINE_OPT_VECTOR_TMO_NS_NUM,
+	CMD_LINE_OPTPKT_BURST_NUM
 };
 
 static const struct option lgopts[] = {
@@ -753,6 +802,7 @@ static const struct option lgopts[] = {
 	{CMD_LINE_OPT_RULE_IPV4,   1, 0, CMD_LINE_OPT_RULE_IPV4_NUM},
 	{CMD_LINE_OPT_RULE_IPV6,   1, 0, CMD_LINE_OPT_RULE_IPV6_NUM},
 	{CMD_LINE_OPT_ALG,   1, 0, CMD_LINE_OPT_ALG_NUM},
+	{CMD_LINE_OPT_PKT_BURST,   1, 0, CMD_LINE_OPTPKT_BURST_NUM},
 	{NULL, 0, 0, 0}
 };
 
@@ -841,6 +891,10 @@ parse_args(int argc, char **argv)
 			parse_queue_size(optarg, &nb_txd, 0);
 			break;
 
+		case CMD_LINE_OPTPKT_BURST_NUM:
+			parse_pkt_burst(optarg);
+			break;
+
 		case CMD_LINE_OPT_ETH_DEST_NUM:
 			parse_eth_dest(optarg);
 			break;
-- 
2.22.0