diff mbox series

[v2] app/testpmd: support multi-process

Message ID 1615430867-29992-1-git-send-email-humin29@huawei.com (mailing list archive)
State Superseded, archived
Headers show
Series [v2] app/testpmd: support multi-process | expand

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Context Check Description
ci/iol-testing fail Testing issues
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-abi-testing success Testing PASS
ci/iol-mellanox-Functional success Functional Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/github-robot fail github build: failed
ci/travis-robot fail travis build: failed
ci/Intel-compilation fail Compilation issues
ci/checkpatch success coding style OK

Commit Message

Min Hu (Connor) March 11, 2021, 2:47 a.m. UTC
From: Lijun Ou <oulijun@huawei.com>

This patch adds multi-process support for testpmd.
The test cmd example as follows:
the primary cmd:
./dpdk-testpmd -a xxx --proc-type=auto -l 0-1 -- -i \
--rxq=4 --txq=4 --num-procs=2 --proc-id=0

the secondary cmd:
./dpdk-testpmd -a xxx --proc-type=auto -l 2-3 -- -i \
--rxq=4 --txq=4 --num-procs=2 --proc-id=1

Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
---
 app/test-pmd/cmdline.c                |  12 ++-
 app/test-pmd/config.c                 |   9 ++-
 app/test-pmd/parameters.c             |  11 +++
 app/test-pmd/testpmd.c                | 138 ++++++++++++++++++++++------------
 app/test-pmd/testpmd.h                |   7 ++
 doc/guides/testpmd_app_ug/run_app.rst |  69 +++++++++++++++++
 6 files changed, 196 insertions(+), 50 deletions(-)

Comments

Ajit Khaparde March 22, 2021, 2:27 a.m. UTC | #1
:::snip::::

> +*   ``--proc-type``
> +       Specify a given process instance as the primary or secondary DPDK instance. ``auto`` set here is ok.
> +
> +*   ``-l CORELIST``
> +       List of cores to run on. the corelist should be different in primary process and secondary process.
> +
> +*   ``--rxq=N``
> +
> +    Set the number of RX queues per port to N, where 1 <= N <= 65535.
> +    The default value is 1. N is the sum of queues used by primary and secondary process.
If RxQ is 1, how will it be shared between the primary and secondary processes?
Should the number of rings be a multiple of the number of processes?

> +
> +*   ``--txq=N``
> +
> +    Set the number of TX queues per port to N, where 1 <= N <= 65535.
> +    The default value is 1. N is the sum of queues used by primary and secondary process.
Same as above. How will a single ring be used across primary and
secondary processes?

> +
> +*   ``--num-procs=N``
> +
> +       The number of processes which will be used.
> +
> +*   ``--proc-id=id``
> +
> +       The id of the current process (id < num-procs). id should be different in primary process and secondary process.
> +
> +Calculation rule for queue:
> +All queues are allocated to different processes based on proc_num and proc_id.
> +Calculation rule for the Testpmd to allocate queues to each process:
> +start(queue start id) = proc_id * nb_q / num_procs;
> +end(queue end id) = start + nb_q / num_procs;
> +
> +For example, if supports 4 txq and rxq
> +the 0~1 for primary process
> +the 2~3 for secondary process
> +
> +Most dev ops is supported in primary and secondary process. While secondary process is not permitted
> +to allocate or release shared memory, so some ops are not supported as follows:
> +``dev_start``
> +``dev_stop``
> +``rx_queue_setup``
> +``tx_queue_setup``
> +``rx_queue_release``
> +``tx_queue_release``
> +
> +RTE_FLOW supported, it applies only on its own process on SW side, but all on HW size.
> +stats supported, stats will not change when one quit and start, As they share the same buffer to store the stats.
> +RSS supported, Primary process and secondary process has separate queues to use, RSS will work in their own queues whether primary and secondary process.
> --
> 2.7.4
>
Min Hu (Connor) March 22, 2021, 6:35 a.m. UTC | #2
在 2021/3/22 10:27, Ajit Khaparde 写道:
> :::snip::::
> 
>> +*   ``--proc-type``
>> +       Specify a given process instance as the primary or secondary DPDK instance. ``auto`` set here is ok.
>> +
>> +*   ``-l CORELIST``
>> +       List of cores to run on. the corelist should be different in primary process and secondary process.
>> +
>> +*   ``--rxq=N``
>> +
>> +    Set the number of RX queues per port to N, where 1 <= N <= 65535.
>> +    The default value is 1. N is the sum of queues used by primary and secondary process.
> If RxQ is 1, how will it be shared between the primary and secondary processes?
Yes, your are right.the range of RxQ(or TxQ) is wrong.
As primary instance and secondary instance should have separate queues, 
and each should occupy at least one queue. So the range of RxQ(or TxQ) 
shoud be no less than two.

> Should the number of rings be a multiple of the number of process  The number of rings had better be a multiple of the number of processes.
  If not, redundant queues will exist after queues are allocated to 
processes. After RSS is enabled, packet loss occurs when traffic is sent 
to all processes at the same time. Some traffic enters redundant queues 
and cannot be forwarded.
  I will fix it in v4.Thanks.

>> +
>> +*   ``--txq=N``
>> +
>> +    Set the number of TX queues per port to N, where 1 <= N <= 65535.
>> +    The default value is 1. N is the sum of queues used by primary and secondary process.
> Same as above. How will a single ring be used across primary and
> secondary processes?
Just same as above, I will fix it in v4.
Thanks.

> 
>> +
>> +*   ``--num-procs=N``
>> +
>> +       The number of processes which will be used.
>> +
>> +*   ``--proc-id=id``
>> +
>> +       The id of the current process (id < num-procs). id should be different in primary process and secondary process.
>> +
>> +Calculation rule for queue:
>> +All queues are allocated to different processes based on proc_num and proc_id.
>> +Calculation rule for the Testpmd to allocate queues to each process:
>> +start(queue start id) = proc_id * nb_q / num_procs;
>> +end(queue end id) = start + nb_q / num_procs;
>> +
>> +For example, if supports 4 txq and rxq
>> +the 0~1 for primary process
>> +the 2~3 for secondary process
>> +
>> +Most dev ops is supported in primary and secondary process. While secondary process is not permitted
>> +to allocate or release shared memory, so some ops are not supported as follows:
>> +``dev_start``
>> +``dev_stop``
>> +``rx_queue_setup``
>> +``tx_queue_setup``
>> +``rx_queue_release``
>> +``tx_queue_release``
>> +
>> +RTE_FLOW supported, it applies only on its own process on SW side, but all on HW size.
>> +stats supported, stats will not change when one quit and start, As they share the same buffer to store the stats.
>> +RSS supported, Primary process and secondary process has separate queues to use, RSS will work in their own queues whether primary and secondary process.
>> --
>> 2.7.4
>>
diff mbox series

Patch

diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 14110eb..287d7a0 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -71,8 +71,6 @@ 
 #include "cmdline_tm.h"
 #include "bpf_cmd.h"
 
-static struct cmdline *testpmd_cl;
-
 static void cmd_reconfig_device_queue(portid_t id, uint8_t dev, uint8_t queue);
 
 /* *** Help command with introduction. *** */
@@ -5351,6 +5349,12 @@  cmd_set_flush_rx_parsed(void *parsed_result,
 		__rte_unused void *data)
 {
 	struct cmd_set_flush_rx *res = parsed_result;
+
+	if (num_procs > 1 && (strcmp(res->mode, "on") == 0)) {
+		printf("multi-process doesn't support to flush rx queues.\n");
+		return;
+	}
+
 	no_flush_rx = (uint8_t)((strcmp(res->mode, "on") == 0) ? 0 : 1);
 }
 
@@ -17227,6 +17231,10 @@  prompt(void)
 		printf("Cannot set exit function for cmdline\n");
 
 	cmdline_interact(testpmd_cl);
+	if (unlikely(f_quit == 1)) {
+		dup2(testpmd_fd_copy, testpmd_cl->s_in);
+		close(testpmd_fd_copy);
+	}
 	if (ret != 0)
 		cmdline_stdin_exit(testpmd_cl);
 }
diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 576d5ac..9edf84a 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -2827,6 +2827,8 @@  rss_fwd_config_setup(void)
 	queueid_t  rxq;
 	queueid_t  nb_q;
 	streamid_t  sm_id;
+	int start;
+	int end;
 
 	nb_q = nb_rxq;
 	if (nb_q > nb_txq)
@@ -2844,7 +2846,10 @@  rss_fwd_config_setup(void)
 	init_fwd_streams();
 
 	setup_fwd_config_of_each_lcore(&cur_fwd_config);
-	rxp = 0; rxq = 0;
+	start = proc_id * nb_q / num_procs;
+	end = start + nb_q / num_procs;
+	rxp = 0;
+	rxq = start;
 	for (sm_id = 0; sm_id < cur_fwd_config.nb_fwd_streams; sm_id++) {
 		struct fwd_stream *fs;
 
@@ -2861,6 +2866,8 @@  rss_fwd_config_setup(void)
 			continue;
 		rxp = 0;
 		rxq++;
+		if (rxq >= end)
+			rxq = start;
 	}
 }
 
diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
index c8acd5d..1a5bf25 100644
--- a/app/test-pmd/parameters.c
+++ b/app/test-pmd/parameters.c
@@ -45,6 +45,8 @@ 
 #include <rte_flow.h>
 
 #include "testpmd.h"
+#define PARAM_PROC_ID "proc-id"
+#define PARAM_NUM_PROCS "num-procs"
 
 static void
 usage(char* progname)
@@ -605,6 +607,8 @@  launch_args_parse(int argc, char** argv)
 		{ "rx-mq-mode",                 1, 0, 0 },
 		{ "record-core-cycles",         0, 0, 0 },
 		{ "record-burst-stats",         0, 0, 0 },
+		{ PARAM_NUM_PROCS,              1, 0, 0 },
+		{ PARAM_PROC_ID,                1, 0, 0 },
 		{ 0, 0, 0, 0 },
 	};
 
@@ -1366,6 +1370,13 @@  launch_args_parse(int argc, char** argv)
 				record_core_cycles = 1;
 			if (!strcmp(lgopts[opt_idx].name, "record-burst-stats"))
 				record_burst_stats = 1;
+
+			if (strncmp(lgopts[opt_idx].name,
+				    PARAM_NUM_PROCS, 8) == 0)
+				num_procs = atoi(optarg);
+			if (strncmp(lgopts[opt_idx].name,
+				    PARAM_PROC_ID, 7) == 0)
+				proc_id = atoi(optarg);
 			break;
 		case 'h':
 			usage(argv[0]);
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 1a57324..bbd45d9 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -63,6 +63,8 @@ 
 
 #include "testpmd.h"
 
+int testpmd_fd_copy = 500; /* the copy of STDIN_FILENO */
+
 #ifndef MAP_HUGETLB
 /* FreeBSD may not have MAP_HUGETLB (in fact, it probably doesn't) */
 #define HUGE_FLAG (0x40000)
@@ -125,6 +127,9 @@  uint8_t port_numa[RTE_MAX_ETHPORTS];
  */
 uint8_t rxring_numa[RTE_MAX_ETHPORTS];
 
+int proc_id;
+unsigned int num_procs = 1;
+
 /*
  * Store specified sockets on which TX ring to be used by ports
  * is allocated.
@@ -982,16 +987,26 @@  mbuf_pool_create(uint16_t mbuf_seg_size, unsigned nb_mbuf,
 			/* wrapper to rte_mempool_create() */
 			TESTPMD_LOG(INFO, "preferred mempool ops selected: %s\n",
 					rte_mbuf_best_mempool_ops());
-			rte_mp = rte_pktmbuf_pool_create(pool_name, nb_mbuf,
-				mb_mempool_cache, 0, mbuf_seg_size, socket_id);
+			if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+				rte_mp = rte_pktmbuf_pool_create(pool_name,
+					 nb_mbuf, mb_mempool_cache, 0,
+					 mbuf_seg_size, socket_id);
+			else
+				rte_mp = rte_mempool_lookup(pool_name);
+
 			break;
 		}
 	case MP_ALLOC_ANON:
 		{
-			rte_mp = rte_mempool_create_empty(pool_name, nb_mbuf,
-				mb_size, (unsigned int) mb_mempool_cache,
-				sizeof(struct rte_pktmbuf_pool_private),
-				socket_id, mempool_flags);
+			if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+				rte_mp = rte_mempool_create_empty(pool_name,
+					nb_mbuf, mb_size,
+					(unsigned int)mb_mempool_cache,
+					sizeof(struct rte_pktmbuf_pool_private),
+					socket_id, mempool_flags);
+			else
+				rte_mp = rte_mempool_lookup(pool_name);
+
 			if (rte_mp == NULL)
 				goto err;
 
@@ -1021,9 +1036,13 @@  mbuf_pool_create(uint16_t mbuf_seg_size, unsigned nb_mbuf,
 
 			TESTPMD_LOG(INFO, "preferred mempool ops selected: %s\n",
 					rte_mbuf_best_mempool_ops());
-			rte_mp = rte_pktmbuf_pool_create(pool_name, nb_mbuf,
-					mb_mempool_cache, 0, mbuf_seg_size,
-					heap_socket);
+			if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+				rte_mp = rte_pktmbuf_pool_create(pool_name,
+					 nb_mbuf, mb_mempool_cache, 0,
+					 mbuf_seg_size, heap_socket);
+			else
+				rte_mp = rte_mempool_lookup(pool_name);
+
 			break;
 		}
 	case MP_ALLOC_XBUF:
@@ -1994,6 +2013,12 @@  flush_fwd_rx_queues(void)
 	uint64_t prev_tsc = 0, diff_tsc, cur_tsc, timer_tsc = 0;
 	uint64_t timer_period;
 
+	if (num_procs > 1) {
+		printf("multi-process not support for flushing fwd rx "
+		       "queues, skip the below lines and return.\n");
+		return;
+	}
+
 	/* convert to number of cycles */
 	timer_period = rte_get_timer_hz(); /* 1 second timeout */
 
@@ -2503,21 +2528,28 @@  start_port(portid_t pid)
 				return -1;
 			}
 			/* configure port */
-			diag = rte_eth_dev_configure(pi, nb_rxq + nb_hairpinq,
+			if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+				diag = rte_eth_dev_configure(pi,
+						     nb_rxq + nb_hairpinq,
 						     nb_txq + nb_hairpinq,
 						     &(port->dev_conf));
-			if (diag != 0) {
-				if (rte_atomic16_cmpset(&(port->port_status),
-				RTE_PORT_HANDLING, RTE_PORT_STOPPED) == 0)
-					printf("Port %d can not be set back "
-							"to stopped\n", pi);
-				printf("Fail to configure port %d\n", pi);
-				/* try to reconfigure port next time */
-				port->need_reconfig = 1;
-				return -1;
+				if (diag != 0) {
+					if (rte_atomic16_cmpset(
+							&(port->port_status),
+							RTE_PORT_HANDLING,
+							RTE_PORT_STOPPED) == 0)
+						printf("Port %d can not be set "
+						       "back to stopped\n", pi);
+					printf("Fail to configure port %d\n",
+						pi);
+					/* try to reconfigure port next time */
+					port->need_reconfig = 1;
+					return -1;
+				}
 			}
 		}
-		if (port->need_reconfig_queues > 0) {
+		if (port->need_reconfig_queues > 0 &&
+		    rte_eal_process_type() == RTE_PROC_PRIMARY) {
 			port->need_reconfig_queues = 0;
 			/* setup tx queues */
 			for (qi = 0; qi < nb_txq; qi++) {
@@ -2618,15 +2650,18 @@  start_port(portid_t pid)
 		cnt_pi++;
 
 		/* start port */
-		if (rte_eth_dev_start(pi) < 0) {
-			printf("Fail to start port %d\n", pi);
+		if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+			diag = rte_eth_dev_start(pi);
+			if (diag < 0) {
+				printf("Fail to start port %d\n", pi);
 
-			/* Fail to setup rx queue, return */
-			if (rte_atomic16_cmpset(&(port->port_status),
-				RTE_PORT_HANDLING, RTE_PORT_STOPPED) == 0)
-				printf("Port %d can not be set back to "
+				/* Fail to setup rx queue, return */
+				if (rte_atomic16_cmpset(&(port->port_status),
+				    RTE_PORT_HANDLING, RTE_PORT_STOPPED) == 0)
+					printf("Port %d can not be set back to "
 							"stopped\n", pi);
-			continue;
+				continue;
+			}
 		}
 
 		if (rte_atomic16_cmpset(&(port->port_status),
@@ -2755,7 +2790,8 @@  stop_port(portid_t pid)
 		if (port->flow_list)
 			port_flow_flush(pi);
 
-		if (rte_eth_dev_stop(pi) != 0)
+		if (rte_eal_process_type() == RTE_PROC_PRIMARY &&
+		    rte_eth_dev_stop(pi) != 0)
 			RTE_LOG(ERR, EAL, "rte_eth_dev_stop failed for port %u\n",
 				pi);
 
@@ -2824,8 +2860,10 @@  close_port(portid_t pid)
 			continue;
 		}
 
-		port_flow_flush(pi);
-		rte_eth_dev_close(pi);
+		if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+			port_flow_flush(pi);
+		if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+			rte_eth_dev_close(pi);
 	}
 
 	remove_invalid_ports();
@@ -3089,7 +3127,7 @@  pmd_test_exit(void)
 		}
 	}
 	for (i = 0 ; i < RTE_DIM(mempools) ; i++) {
-		if (mempools[i])
+		if (rte_eal_process_type() == RTE_PROC_PRIMARY && mempools[i])
 			rte_mempool_free(mempools[i]);
 	}
 
@@ -3611,6 +3649,10 @@  init_port_dcb_config(portid_t pid,
 	int retval;
 	uint16_t i;
 
+	if (num_procs > 1) {
+		printf("The multi-process feature doesn't support dcb.\n");
+		return -ENOTSUP;
+	}
 	rte_port = &ports[pid];
 
 	memset(&port_conf, 0, sizeof(struct rte_eth_conf));
@@ -3709,13 +3751,6 @@  init_port(void)
 }
 
 static void
-force_quit(void)
-{
-	pmd_test_exit();
-	prompt_exit();
-}
-
-static void
 print_stats(void)
 {
 	uint8_t i;
@@ -3746,12 +3781,16 @@  signal_handler(int signum)
 		if (latencystats_enabled != 0)
 			rte_latencystats_uninit();
 #endif
-		force_quit();
 		/* Set flag to indicate the force termination. */
 		f_quit = 1;
-		/* exit with the expected status */
-		signal(signum, SIG_DFL);
-		kill(getpid(), signum);
+		if (interactive == 1) {
+			dup2(testpmd_cl->s_in, testpmd_fd_copy);
+			close(testpmd_cl->s_in);
+		} else {
+			dup2(0, testpmd_fd_copy);
+			close(0);
+		}
+
 	}
 }
 
@@ -3776,10 +3815,6 @@  main(int argc, char** argv)
 		rte_exit(EXIT_FAILURE, "Cannot init EAL: %s\n",
 			 rte_strerror(rte_errno));
 
-	if (rte_eal_process_type() == RTE_PROC_SECONDARY)
-		rte_exit(EXIT_FAILURE,
-			 "Secondary process type not supported.\n");
-
 	ret = register_eth_event_callback();
 	if (ret != 0)
 		rte_exit(EXIT_FAILURE, "Cannot register for ethdev events");
@@ -3875,8 +3910,10 @@  main(int argc, char** argv)
 		}
 	}
 
-	if (!no_device_start && start_port(RTE_PORT_ALL) != 0)
+	if (!no_device_start && start_port(RTE_PORT_ALL) != 0) {
+		pmd_test_exit();
 		rte_exit(EXIT_FAILURE, "Start ports failed\n");
+	}
 
 	/* set all ports to promiscuous mode by default */
 	RTE_ETH_FOREACH_DEV(port_id) {
@@ -3922,6 +3959,8 @@  main(int argc, char** argv)
 		}
 		prompt();
 		pmd_test_exit();
+		if (unlikely(f_quit == 1))
+			prompt_exit();
 	} else
 #endif
 	{
@@ -3957,6 +3996,11 @@  main(int argc, char** argv)
 		printf("Press enter to exit\n");
 		rc = read(0, &c, 1);
 		pmd_test_exit();
+		if (unlikely(f_quit == 1)) {
+			dup2(testpmd_fd_copy, 0);
+			close(testpmd_fd_copy);
+			prompt_exit();
+		}
 		if (rc < 0)
 			return 1;
 	}
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index ce83f31..6d13417 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -13,6 +13,7 @@ 
 #include <rte_gso.h>
 #include <cmdline.h>
 #include <sys/queue.h>
+#include  "cmdline.h"
 
 #define RTE_PORT_ALL            (~(portid_t)0x0)
 
@@ -24,6 +25,10 @@ 
 #define RTE_PORT_CLOSED         (uint16_t)2
 #define RTE_PORT_HANDLING       (uint16_t)3
 
+uint8_t f_quit;
+int testpmd_fd_copy;
+struct cmdline *testpmd_cl;
+
 /*
  * It is used to allocate the memory for hash key.
  * The hash key size is NIC dependent.
@@ -422,6 +427,8 @@  extern uint64_t noisy_lkup_mem_sz;
 extern uint64_t noisy_lkup_num_writes;
 extern uint64_t noisy_lkup_num_reads;
 extern uint64_t noisy_lkup_num_reads_writes;
+extern int proc_id;
+extern unsigned int num_procs;
 
 extern uint8_t dcb_config;
 extern uint8_t dcb_test;
diff --git a/doc/guides/testpmd_app_ug/run_app.rst b/doc/guides/testpmd_app_ug/run_app.rst
index 6745072..7e1b95d 100644
--- a/doc/guides/testpmd_app_ug/run_app.rst
+++ b/doc/guides/testpmd_app_ug/run_app.rst
@@ -536,3 +536,72 @@  The command line options are:
     bit 1 - two hairpin ports paired
     bit 0 - two hairpin ports loop
     The default value is 0. Hairpin will use single port mode and implicit Tx flow mode.
+
+
+Testpmd Support Multi Process Command-line Options
+----------------------------
+
+The following are the command-line options for the testpmd applications(support multi process).
+They must be separated from the EAL options, shown in the previous section, with a ``--`` separator:
+
+.. code-block:: console
+
+	primary process:
+    sudo ./dpdk-testpmd -a xxx --proc-type=auto -l 0-1 -- -i --rxq=4 --txq=4 --num-procs=2 --proc-id=0
+
+	secondary process:
+	sudo ./dpdk-testpmd -a xxx --proc-type=auto -l 2-3 -- -i --rxq=4 --txq=4 --num-procs=2 --proc-id=1
+
+The command line options are:
+
+*   ``-a, --allow``
+
+	Add a device to the allow list. ``xxx`` means device used which should be the same in primary process
+	and secondary process.
+
+*   ``--proc-type``
+	Specify a given process instance as the primary or secondary DPDK instance. ``auto`` set here is ok.
+
+*   ``-l CORELIST``
+	List of cores to run on. the corelist should be different in primary process and secondary process.
+
+*   ``--rxq=N``
+
+    Set the number of RX queues per port to N, where 1 <= N <= 65535.
+    The default value is 1. N is the sum of queues used by primary and secondary process.
+
+*   ``--txq=N``
+
+    Set the number of TX queues per port to N, where 1 <= N <= 65535.
+    The default value is 1. N is the sum of queues used by primary and secondary process.
+
+*   ``--num-procs=N``
+
+	The number of processes which will be used.
+
+*   ``--proc-id=id``
+
+	The id of the current process (id < num-procs). id should be different in primary process and secondary process.
+
+Calculation rule for queue:
+All queues are allocated to different processes based on proc_num and proc_id.
+Calculation rule for the Testpmd to allocate queues to each process:
+start(queue start id) = proc_id * nb_q / num_procs;
+end(queue end id) = start + nb_q / num_procs;
+
+For example, if supports 4 txq and rxq
+the 0~1 for primary process
+the 2~3 for secondary process
+
+Most dev ops is supported in primary and secondary process. While secondary process is not permitted
+to allocate or release shared memory, so some ops are not supported as follows:
+``dev_start``
+``dev_stop``
+``rx_queue_setup``
+``tx_queue_setup``
+``rx_queue_release``
+``tx_queue_release``
+
+RTE_FLOW supported, it applies only on its own process on SW side, but all on HW size.
+stats supported, stats will not change when one quit and start, As they share the same buffer to store the stats.
+RSS supported, Primary process and secondary process has separate queues to use, RSS will work in their own queues whether primary and secondary process.