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

[Jie Hai]

Hi, all maintainers,

Kindly ping for review.

Thanks,
Jie Hai
On 2024/10/12 16:40, Jie Hai wrote:
> 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 at 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;