[PATCH bpf-next 3/4] samples/bpf: xdpsock: add period cycle time to Tx operation

[Ong Boon Leong <boon.leong.ong@intel.com>]

Tx cycle time is in micro-seconds unit. By combining the batch size (-b M)
and Tx cycle time (-T|--tx-cycle N), xdpsock now can transmit batch-size of
packets every N-us periodically.

For example to transmit 1 packet each 1ms cycle time for total of 2000000
packets:

 $ xdpsock -i eth0 -T -N -z -T 1000 -b 1 -C 2000000

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1000           1996872

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1000           1997872

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1000           1998872

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1000           1999872

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 128            2000000

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           0.00
rx                 0              0
tx                 0              2000000

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 samples/bpf/xdpsock_user.c | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 691f442bbb2..61d4063f11a 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -111,6 +111,7 @@ static u32 opt_num_xsks = 1;
 static u32 prog_id;
 static bool opt_busy_poll;
 static bool opt_reduced_cap;
+static unsigned long opt_cycle_time;
 
 struct vlan_ethhdr {
 	unsigned char h_dest[6];
@@ -173,6 +174,8 @@ struct xsk_socket_info {
 	struct xsk_app_stats app_stats;
 	struct xsk_driver_stats drv_stats;
 	u32 outstanding_tx;
+	unsigned long prev_tx_time;
+	unsigned long tx_cycle_time;
 };
 
 static int num_socks;
@@ -972,6 +975,7 @@ static struct option long_options[] = {
 	{"tx-vlan-pri", required_argument, 0, 'K'},
 	{"tx-dmac", required_argument, 0, 'G'},
 	{"tx-smac", required_argument, 0, 'H'},
+	{"tx-cycle", required_argument, 0, 'T'},
 	{"extra-stats", no_argument, 0, 'x'},
 	{"quiet", no_argument, 0, 'Q'},
 	{"app-stats", no_argument, 0, 'a'},
@@ -1017,6 +1021,7 @@ static void usage(const char *prog)
 		"  -K, --tx-vlan-pri=n  Tx VLAN Priority [0-7]. Default: %d (For -V|--tx-vlan)\n"
 		"  -G, --tx-dmac=<MAC>  Dest MAC addr of TX frame in aa:bb:cc:dd:ee:ff format (For -V|--tx-vlan)\n"
 		"  -H, --tx-smac=<MAC>  Src MAC addr of TX frame in aa:bb:cc:dd:ee:ff format (For -V|--tx-vlan)\n"
+		"  -T, --tx-cycle=n     Tx cycle time in micro-seconds (For -t|--txonly).\n"
 		"  -x, --extra-stats	Display extra statistics.\n"
 		"  -Q, --quiet          Do not display any stats.\n"
 		"  -a, --app-stats	Display application (syscall) statistics.\n"
@@ -1039,7 +1044,7 @@ static void parse_command_line(int argc, char **argv)
 	opterr = 0;
 
 	for (;;) {
-		c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:VJ:K:G:H:xQaI:BR",
+		c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:VJ:K:G:H:T:xQaI:BR",
 				long_options, &option_index);
 		if (c == -1)
 			break;
@@ -1145,6 +1150,10 @@ static void parse_command_line(int argc, char **argv)
 				usage(basename(argv[0]));
 			}
 			break;
+		case 'T':
+			opt_cycle_time = atoi(optarg);
+			opt_cycle_time *= 1000;
+			break;
 		case 'x':
 			opt_extra_stats = 1;
 			break;
@@ -1350,16 +1359,25 @@ static void rx_drop_all(void)
 	}
 }
 
-static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size)
+static int tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size)
 {
 	u32 idx;
 	unsigned int i;
 
+	if (xsk->tx_cycle_time) {
+		unsigned long now = get_nsecs();
+
+		if ((now - xsk->prev_tx_time) < xsk->tx_cycle_time)
+			return 0;
+
+		xsk->prev_tx_time = now;
+	}
+
 	while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) <
 				      batch_size) {
 		complete_tx_only(xsk, batch_size);
 		if (benchmark_done)
-			return;
+			return 0;
 	}
 
 	for (i = 0; i < batch_size; i++) {
@@ -1375,6 +1393,8 @@ static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size)
 	*frame_nb += batch_size;
 	*frame_nb %= NUM_FRAMES;
 	complete_tx_only(xsk, batch_size);
+
+	return batch_size;
 }
 
 static inline int get_batch_size(int pkt_cnt)
@@ -1407,6 +1427,7 @@ static void complete_tx_only_all(void)
 static void tx_only_all(void)
 {
 	struct pollfd fds[MAX_SOCKS] = {};
+	unsigned long now = get_nsecs();
 	u32 frame_nb[MAX_SOCKS] = {};
 	int pkt_cnt = 0;
 	int i, ret;
@@ -1414,10 +1435,15 @@ static void tx_only_all(void)
 	for (i = 0; i < num_socks; i++) {
 		fds[0].fd = xsk_socket__fd(xsks[i]->xsk);
 		fds[0].events = POLLOUT;
+		if (opt_cycle_time) {
+			xsks[i]->prev_tx_time = now;
+			xsks[i]->tx_cycle_time = opt_cycle_time;
+		}
 	}
 
 	while ((opt_pkt_count && pkt_cnt < opt_pkt_count) || !opt_pkt_count) {
 		int batch_size = get_batch_size(pkt_cnt);
+		int tx_cnt = 0;
 
 		if (opt_poll) {
 			for (i = 0; i < num_socks; i++)
@@ -1431,9 +1457,9 @@ static void tx_only_all(void)
 		}
 
 		for (i = 0; i < num_socks; i++)
-			tx_only(xsks[i], &frame_nb[i], batch_size);
+			tx_cnt += tx_only(xsks[i], &frame_nb[i], batch_size);
 
-		pkt_cnt += batch_size;
+		pkt_cnt += tx_cnt;
 
 		if (benchmark_done)
 			break;
-- 
2.25.1