[PATCH] examples/l3fwd: add hard code to collect empty poll and NIC counters

[Feifei Wang <feifei.wang2@arm.com>]

This patch is to collect empty poll of 'rte_eth_rx_burst' functions in
dpdk l3fwd application. Empty poll means Rx burst function receives no
pkts in one loop.

Furthermore, we also add 'nic_xstats_display' API to show NIC counters.

Usage:
With this patch, no special settings, just run l3fwd, and when you
stoping l3fwd, thread will print the info above.

Note:
This patch has just a slight impact on performance and can be ignored.

dpdk version:23.03

Suggested-by: Lijian Zhang <lijian.zhang@arm.com>
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
---
 examples/l3fwd/l3fwd.h     | 68 ++++++++++++++++++++++++++++++++++++++
 examples/l3fwd/l3fwd_lpm.c | 26 +++++++++++++--
 examples/l3fwd/main.c      | 22 ++++++++++++
 3 files changed, 114 insertions(+), 2 deletions(-)

diff --git a/examples/l3fwd/l3fwd.h b/examples/l3fwd/l3fwd.h
index b55855c932..2b3fca62f3 100644
--- a/examples/l3fwd/l3fwd.h
+++ b/examples/l3fwd/l3fwd.h
@@ -56,6 +56,17 @@
 #define L3FWD_HASH_ENTRIES		(1024*1024*1)
 #endif
 
+struct lcore_stats {
+    uint32_t nb_rx_pkts[16];
+    uint32_t num_loop[16];
+    uint32_t none_loop[16];
+    uint32_t no_full_loop[16];
+    float  none_loop_per[16];
+    float no_full_loop_per[16];
+} __rte_cache_aligned;
+
+extern struct lcore_stats stats[RTE_MAX_LCORE];
+
 struct parm_cfg {
 	const char *rule_ipv4_name;
 	const char *rule_ipv6_name;
@@ -115,6 +126,63 @@ extern struct acl_algorithms acl_alg[];
 
 extern uint32_t max_pkt_len;
 
+static inline void
+nic_xstats_display(uint32_t port_id)
+{
+        struct rte_eth_xstat *xstats;
+        int cnt_xstats, idx_xstat;
+        struct rte_eth_xstat_name *xstats_names;
+
+        printf("###### NIC extended statistics for port %-2d\n", port_id);
+        if (!rte_eth_dev_is_valid_port(port_id)) {
+                fprintf(stderr, "Error: Invalid port number %i\n", port_id);
+                return;
+        }
+
+        /* Get count */
+        cnt_xstats = rte_eth_xstats_get_names(port_id, NULL, 0);
+        if (cnt_xstats  < 0) {
+                fprintf(stderr, "Error: Cannot get count of xstats\n");
+                return;
+        }
+
+        /* Get id-name lookup table */
+        xstats_names = malloc(sizeof(struct rte_eth_xstat_name) * cnt_xstats);
+        if (xstats_names == NULL) {
+                fprintf(stderr, "Cannot allocate memory for xstats lookup\n");
+                return;
+        }
+        if (cnt_xstats != rte_eth_xstats_get_names(
+                        port_id, xstats_names, cnt_xstats)) {
+                fprintf(stderr, "Error: Cannot get xstats lookup\n");
+                free(xstats_names);
+                return;
+        }
+
+        /* Get stats themselves */
+        xstats = malloc(sizeof(struct rte_eth_xstat) * cnt_xstats);
+        if (xstats == NULL) {
+                fprintf(stderr, "Cannot allocate memory for xstats\n");
+                free(xstats_names);
+                return;
+        }
+        if (cnt_xstats != rte_eth_xstats_get(port_id, xstats, cnt_xstats)) {
+                fprintf(stderr, "Error: Unable to get xstats\n");
+                free(xstats_names);
+                free(xstats);
+                return;
+        }
+
+        /* Display xstats */
+        for (idx_xstat = 0; idx_xstat < cnt_xstats; idx_xstat++) {
+                printf("%s: %"PRIu64"\n",
+                        xstats_names[idx_xstat].name,
+                        xstats[idx_xstat].value);
+        }
+        free(xstats_names);
+        free(xstats);
+}
+
 /* 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_lpm.c b/examples/l3fwd/l3fwd_lpm.c
index 4ac1925c84..9e27e954b9 100644
--- a/examples/l3fwd/l3fwd_lpm.c
+++ b/examples/l3fwd/l3fwd_lpm.c
@@ -41,6 +41,8 @@
 static struct rte_lpm *ipv4_l3fwd_lpm_lookup_struct[NB_SOCKETS];
 static struct rte_lpm6 *ipv6_l3fwd_lpm_lookup_struct[NB_SOCKETS];
 
+extern struct lcore_stats stats[RTE_MAX_LCORE];
+
 /* Performing LPM-based lookups. 8< */
 static inline uint16_t
 lpm_get_ipv4_dst_port(const struct rte_ipv4_hdr *ipv4_hdr,
@@ -153,6 +155,7 @@ lpm_main_loop(__rte_unused void *dummy)
 	struct lcore_conf *qconf;
 	const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
 		US_PER_S * BURST_TX_DRAIN_US;
+	bool start_count = 0;
 
 	lcore_id = rte_lcore_id();
 	qconf = &lcore_conf[lcore_id];
@@ -207,8 +210,22 @@ lpm_main_loop(__rte_unused void *dummy)
 			queueid = qconf->rx_queue_list[i].queue_id;
 			nb_rx = rte_eth_rx_burst(portid, queueid, pkts_burst,
 				MAX_PKT_BURST);
-			if (nb_rx == 0)
-				continue;
+			if (start_count == 0) {
+				if (nb_rx != 0)
+					start_count = 1;
+			}
+
+			if (start_count == 1) {
+				stats[lcore_id].nb_rx_pkts[i] += nb_rx;
+				stats[lcore_id].num_loop[i]++;
+				if (nb_rx < MAX_PKT_BURST && nb_rx > 0)
+					stats[lcore_id].no_full_loop[i]++;
+
+				if (nb_rx == 0) {
+					stats[lcore_id].none_loop[i]++;
+					continue;
+				}
+			}
 
 #if defined RTE_ARCH_X86 || defined __ARM_NEON \
 			 || defined RTE_ARCH_PPC_64
@@ -223,6 +240,11 @@ lpm_main_loop(__rte_unused void *dummy)
 		cur_tsc = rte_rdtsc();
 	}
 
+	for (i = 0; i < n_rx_q; ++i) {
+		stats[lcore_id].none_loop_per[i] = (float)stats[lcore_id].none_loop[i]/stats[lcore_id].num_loop[i]*100;
+		stats[lcore_id].no_full_loop_per[i] = (float)stats[lcore_id].no_full_loop[i]/stats[lcore_id].num_loop[i]*100;
+	}
+
 	return 0;
 }
 
diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index a4f061537e..4727215eae 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -53,6 +53,8 @@
 
 #define MAX_LCORE_PARAMS 1024
 
+struct lcore_stats stats[RTE_MAX_LCORE];
+
 uint16_t nb_rxd = RX_DESC_DEFAULT;
 uint16_t nb_txd = TX_DESC_DEFAULT;
 
@@ -1592,6 +1594,26 @@ main(int argc, char **argv)
 	} else {
 		rte_eal_mp_wait_lcore();
 
+		for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
+			if (rte_lcore_is_enabled(lcore_id) == 0)
+				continue;
+			qconf = &lcore_conf[lcore_id];
+			for (queue = 0; queue < qconf->n_rx_queue; ++queue) {
+				printf("\nlcore id:%d\n", lcore_id);
+				printf("queue_id:%d\n",queue);
+				printf("Rx pkt %d\n", stats[lcore_id].nb_rx_pkts[queue]);
+				printf("loop number: %d, 0 pkts loop:%d, <32 pkts loop:%d\n",
+					stats[lcore_id].num_loop[queue], stats[lcore_id].none_loop[queue], stats[lcore_id].no_full_loop[queue]);
+				printf("0 pkts loop percentage:%.2f%%, <32 pkts loop percentage:%.2f%%\n",
+					stats[lcore_id].none_loop_per[queue], stats[lcore_id].no_full_loop_per[queue]);
+				printf("------------------------------------\n\n");
+
+			}
+		}
+
+		nic_xstats_display(0);
+		nic_xstats_display(1);
+
 		RTE_ETH_FOREACH_DEV(portid) {
 			if ((enabled_port_mask & (1 << portid)) == 0)
 				continue;
-- 
2.25.1