[PATCH v2] examples/l3fwd: support setting the data size of mbuf

[Chaoyong He]

From: Long Wu <long.wu at corigine.com>

The previous code used a macro as the data size for mbuf
to create the mempool and users cannot modify the size.

Now modify the code to support setting the data size of
mbuf by '--mbuf-size' parameter. If user does not add the
parameter in start command line, the default size is still
'RTE_MBUF_DEFAULT_BUF_SIZE'.

Examples:
dpdk-l3fwd -l 0-3 -- -p 0x03 --mbuf-size=4096

Signed-off-by: Long Wu <long.wu at corigine.com>
Reviewed-by: Chaoyong He <chaoyong.he at corigine.com>
Acked-by: Morten Brørup <mb at smartsharesystems.com>

---
v2:
* Modify some logic following the advices of reviewer.
* Add the 'Acked-by' tag.
---
 doc/guides/sample_app_ug/l3_forward.rst |  2 ++
 examples/l3fwd/main.c                   | 31 ++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/doc/guides/sample_app_ug/l3_forward.rst b/doc/guides/sample_app_ug/l3_forward.rst
index 1cc2c1dd1d..5afbbb242b 100644
--- a/doc/guides/sample_app_ug/l3_forward.rst
+++ b/doc/guides/sample_app_ug/l3_forward.rst
@@ -143,6 +143,8 @@ Where,
 * ``--alg=<val>:`` optional, ACL classify method to use, one of:
   ``scalar|sse|avx2|neon|altivec|avx512x16|avx512x32``
 
+* ``--mbuf-size=N:`` Optional, Set the data size of mbuf to N bytes.
+
 * ``-E:`` Optional, enable exact match,
   legacy flag, please use ``--lookup=em`` instead.
 
diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 01b763e5ba..ed5d0c2608 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -140,6 +140,7 @@ uint32_t max_pkt_len;
 #ifdef RTE_LIB_EVENTDEV
 static struct rte_mempool *vector_pool[RTE_MAX_ETHPORTS];
 #endif
+static uint16_t mbuf_data_size = RTE_MBUF_DEFAULT_DATAROOM;
 static struct rte_mempool *pktmbuf_pool[RTE_MAX_ETHPORTS][NB_SOCKETS];
 static uint8_t lkp_per_socket[NB_SOCKETS];
 
@@ -448,7 +449,8 @@ print_usage(const char *prgname)
 		"                    One is ACL entry at while line leads with character '%c',\n"
 		"                    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",
+		"  --alg: ACL classify method to use, one of: %s.\n"
+		"  --mbuf-size=N: Set the data size of mbuf to N bytes.\n\n",
 		prgname, RX_DESC_DEFAULT, TX_DESC_DEFAULT,
 		ACL_LEAD_CHAR, ROUTE_LEAD_CHAR, alg);
 }
@@ -667,6 +669,22 @@ parse_lookup(const char *optarg)
 	return 0;
 }
 
+static void
+parse_mbuf_data_size(const char *optarg)
+{
+	char *end = NULL;
+
+	mbuf_data_size = strtoul(optarg, &end, 10);
+	if ((optarg[0] == '\0') || (end == NULL) || (*end != '\0'))
+		rte_exit(EXIT_FAILURE, "Invalid mbuf data size: %s\n", optarg);
+
+	if (mbuf_data_size < RTE_ETHER_MIN_LEN ||
+			mbuf_data_size > 0xFFFF - RTE_PKTMBUF_HEADROOM)
+		rte_exit(EXIT_FAILURE,
+				"mbuf-size should be >= %u and <= %u\n",
+				RTE_ETHER_MIN_LEN, 0xFFFF - RTE_PKTMBUF_HEADROOM);
+}
+
 #define MAX_JUMBO_PKT_LEN  9600
 
 static const char short_options[] =
@@ -698,6 +716,7 @@ 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_MBUF_SIZE "mbuf-size"
 
 enum {
 	/* long options mapped to a short option */
@@ -726,7 +745,8 @@ 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_OPT_MBUF_SIZE_NUM,
 };
 
 static const struct option lgopts[] = {
@@ -753,6 +773,7 @@ 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_MBUF_SIZE, 1, 0, CMD_LINE_OPT_MBUF_SIZE_NUM},
 	{NULL, 0, 0, 0}
 };
 
@@ -934,6 +955,9 @@ parse_args(int argc, char **argv)
 		case CMD_LINE_OPT_ALG_NUM:
 			l3fwd_set_alg(optarg);
 			break;
+		case CMD_LINE_OPT_MBUF_SIZE_NUM:
+			parse_mbuf_data_size(optarg);
+			break;
 		default:
 			print_usage(prgname);
 			return -1;
@@ -1034,7 +1058,8 @@ init_mem(uint16_t portid, unsigned int nb_mbuf)
 			pktmbuf_pool[portid][socketid] =
 				rte_pktmbuf_pool_create(s, nb_mbuf,
 					MEMPOOL_CACHE_SIZE, 0,
-					RTE_MBUF_DEFAULT_BUF_SIZE, socketid);
+					mbuf_data_size + RTE_PKTMBUF_HEADROOM,
+					socketid);
 			if (pktmbuf_pool[portid][socketid] == NULL)
 				rte_exit(EXIT_FAILURE,
 					"Cannot init mbuf pool on socket %d\n",
-- 
2.39.1