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

[Jerin Jacob <jerinjacobk@gmail.com>]

On Thu, May 11, 2023 at 1:55 PM Feifei Wang <feifei.wang2@arm.com> wrote:
>
> 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.

IMO, We should not introduce regression as l3fwd kind of uses as
reference application.
I think, l3fwd should limit to stats exposed by ethdev(i.e directly
from NIC, without performance regression).



>
> 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
>