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. Cyclic TX operation is not applicable if
--poll mode is used.
To transmit 16 packets every 1ms cycle time for total of 100000 packets
silently:
$ xdpsock -i eth0 -T -N -z -T 1000 -b 16 -C 100000
To print cyclic TX schedule variance stats, use --app-stats|-a:
$ xdpsock -i eth0 -T -N -z -T 1000 -b 16 -C 100000 -a
sock0@eth0:0 txonly xdp-drv
pps pkts 0.00
rx 0 0
tx 0 100000
calls/s count
rx empty polls 0 0
fill fail polls 0 0
copy tx sendtos 0 0
tx wakeup sendtos 0 6254
opt polls 0 0
period min ave max cycle
Cyclic TX 1000000 53507 75334 712642 6250
Signed-off-by: Ong Boon Leong <boon.leong.ong@xxxxxxxxx>
---
samples/bpf/xdpsock_user.c | 85 +++++++++++++++++++++++++++++++++++---
1 file changed, 80 insertions(+), 5 deletions(-)
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index e6e9a20375c..a2a42ec4b0e 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -63,12 +63,19 @@
#define VLAN_VID__DEFAULT 1
#define VLAN_PRI__DEFAULT 0
+#define NSEC_PER_SEC 1000000000UL
+#define NSEC_PER_USEC 1000
+
typedef __u64 u64;
typedef __u32 u32;
typedef __u16 u16;
typedef __u8 u8;
static unsigned long prev_time;
+static long tx_cycle_diff_min;
+static long tx_cycle_diff_max;
+static double tx_cycle_diff_ave;
+static long tx_cycle_cnt;
enum benchmark_type {
BENCH_RXDROP = 0,
@@ -115,6 +122,7 @@ static u32 prog_id;
static bool opt_busy_poll;
static bool opt_reduced_cap;
static clockid_t opt_clock = CLOCK_MONOTONIC;
+static unsigned long opt_tx_cycle_ns;
struct vlan_ethhdr {
unsigned char h_dest[6];
@@ -305,6 +313,15 @@ static void dump_app_stats(long dt)
xsks[i]->app_stats.prev_tx_wakeup_sendtos = xsks[i]->app_stats.tx_wakeup_sendtos;
xsks[i]->app_stats.prev_opt_polls = xsks[i]->app_stats.opt_polls;
}
+
+ if (opt_tx_cycle_ns) {
+ printf("\n%-18s %-10s %-10s %-10s %-10s %-10s\n",
+ "", "period", "min", "ave", "max", "cycle");
+ printf("%-18s %-10lu %-10lu %-10lu %-10lu %-10lu\n",
+ "Cyclic TX", opt_tx_cycle_ns, tx_cycle_diff_min,
+ (long)(tx_cycle_diff_ave / tx_cycle_cnt),
+ tx_cycle_diff_max, tx_cycle_cnt);
+ }
}
static bool get_interrupt_number(void)
@@ -1001,6 +1018,7 @@ 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'},
@@ -1047,6 +1065,7 @@ 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"
@@ -1069,7 +1088,7 @@ static void parse_command_line(int argc, char **argv)
opterr = 0;
for (;;) {
- c = getopt_long(argc, argv, "Frtli:q:pSNn:w:czf:muMd:b:C:s:P:VJ:K:G:H:xQaI:BR",
+ c = getopt_long(argc, argv, "Frtli:q:pSNn:w:czf:muMd:b:C:s:P:VJ:K:G:H:T:xQaI:BR",
long_options, &option_index);
if (c == -1)
break;
@@ -1183,6 +1202,10 @@ static void parse_command_line(int argc, char **argv)
usage(basename(argv[0]));
}
break;
+ case 'T':
+ opt_tx_cycle_ns = atoi(optarg);
+ opt_tx_cycle_ns *= NSEC_PER_USEC;
+ break;
case 'x':
opt_extra_stats = 1;
break;
@@ -1388,7 +1411,7 @@ 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;
@@ -1397,7 +1420,7 @@ static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size)
batch_size) {
complete_tx_only(xsk, batch_size);
if (benchmark_done)
- return;
+ return 0;
}
for (i = 0; i < batch_size; i++) {
@@ -1413,6 +1436,8 @@ 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)
@@ -1446,16 +1471,39 @@ static void tx_only_all(void)
{
struct pollfd fds[MAX_SOCKS] = {};
u32 frame_nb[MAX_SOCKS] = {};
+ unsigned long next_tx_ns = 0;
int pkt_cnt = 0;
int i, ret;
+ if (opt_poll && opt_tx_cycle_ns) {
+ fprintf(stderr,
+ "Error: --poll and --tx-cycles are both set\n");
+ return;
+ }
+
for (i = 0; i < num_socks; i++) {
fds[0].fd = xsk_socket__fd(xsks[i]->xsk);
fds[0].events = POLLOUT;
}
+ if (opt_tx_cycle_ns) {
+ /* Align Tx time to micro-second boundary */
+ next_tx_ns = (get_nsecs() / NSEC_PER_USEC + 1) *
+ NSEC_PER_USEC;
+ next_tx_ns += opt_tx_cycle_ns;
+
+ /* Initialize periodic Tx scheduling variance */
+ tx_cycle_diff_min = 1000000000;
+ tx_cycle_diff_max = 0;
+ tx_cycle_diff_ave = 0.0;
+ }
+
while ((opt_pkt_count && pkt_cnt < opt_pkt_count) || !opt_pkt_count) {
int batch_size = get_batch_size(pkt_cnt);
+ struct timespec next;
+ int tx_cnt = 0;
+ long diff;
+ int err;
if (opt_poll) {
for (i = 0; i < num_socks; i++)
@@ -1468,13 +1516,40 @@ static void tx_only_all(void)
continue;
}
+ if (opt_tx_cycle_ns) {
+ next.tv_sec = next_tx_ns / NSEC_PER_SEC;
+ next.tv_nsec = next_tx_ns % NSEC_PER_SEC;
+ err = clock_nanosleep(opt_clock, TIMER_ABSTIME, &next, NULL);
+ if (err) {
+ if (err != EINTR)
+ fprintf(stderr,
+ "clock_nanosleep failed. Err:%d errno:%d\n",
+ err, errno);
+ break;
+ }
+
+ /* Measure periodic Tx scheduling variance */
+ diff = get_nsecs() - next_tx_ns;
+ if (diff < tx_cycle_diff_min)
+ tx_cycle_diff_min = diff;
+
+ if (diff > tx_cycle_diff_max)
+ tx_cycle_diff_max = diff;
+
+ tx_cycle_diff_ave += (double)diff;
+ tx_cycle_cnt++;
+ }
+
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;
+
+ if (opt_tx_cycle_ns)
+ next_tx_ns += opt_tx_cycle_ns;
}
if (opt_pkt_count)
--
2.25.1
