Commit b35fc148 authored by Björn Töpel's avatar Björn Töpel Committed by Daniel Borkmann
Browse files

samples/bpf: Add busy-poll support to xdpsock 



Add a new option to xdpsock, 'B', for busy-polling. This option will
also set the batching size, 'b' option, to the busy-poll budget.

Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-10-bjorn.topel@gmail.com
parent 284cbc61

samples/bpf/xdpsock_user.c

+33 −7
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ static int opt_timeout = 1000; 
static bool opt_need_wakeup = true;

static u32 opt_num_xsks = 1;

static u32 prog_id;

static bool opt_busy_poll;



struct xsk_ring_stats {

	unsigned long rx_npkts;
@@ -911,6 +912,7 @@ static struct option long_options[] = { 
	{"quiet", no_argument, 0, 'Q'},

	{"app-stats", no_argument, 0, 'a'},

	{"irq-string", no_argument, 0, 'I'},

	{"busy-poll", no_argument, 0, 'B'},

	{0, 0, 0, 0}

};
@@ -949,6 +951,7 @@ static void usage(const char *prog) 
		"  -Q, --quiet          Do not display any stats.\n"

		"  -a, --app-stats	Display application (syscall) statistics.\n"

		"  -I, --irq-string	Display driver interrupt statistics for interface associated with irq-string.\n"

		"  -B, --busy-poll      Busy poll.\n"

		"\n";

	fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,

		opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
@@ -964,7 +967,7 @@ 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:xQaI:",

		c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQaI:B",

				long_options, &option_index);

		if (c == -1)

			break;
@@ -1062,7 +1065,9 @@ static void parse_command_line(int argc, char **argv) 
				fprintf(stderr, "ERROR: Failed to get irqs for %s\n", opt_irq_str);

				usage(basename(argv[0]));

			}



			break;

		case 'B':

			opt_busy_poll = 1;

			break;

		default:

			usage(basename(argv[0]));
@@ -1131,7 +1136,7 @@ static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk) 
		while (ret != rcvd) {

			if (ret < 0)

				exit_with_error(-ret);

			if (xsk_ring_prod__needs_wakeup(&umem->fq)) {

			if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&umem->fq)) {

				xsk->app_stats.fill_fail_polls++;

				recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL,

					 NULL);
@@ -1178,7 +1183,7 @@ static void rx_drop(struct xsk_socket_info *xsk) 


	rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);

	if (!rcvd) {

		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {

		if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {

			xsk->app_stats.rx_empty_polls++;

			recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);

		}
@@ -1189,7 +1194,7 @@ static void rx_drop(struct xsk_socket_info *xsk) 
	while (ret != rcvd) {

		if (ret < 0)

			exit_with_error(-ret);

		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {

		if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {

			xsk->app_stats.fill_fail_polls++;

			recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);

		}
@@ -1341,7 +1346,7 @@ static void l2fwd(struct xsk_socket_info *xsk) 


	rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);

	if (!rcvd) {

		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {

		if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {

			xsk->app_stats.rx_empty_polls++;

			recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);

		}
@@ -1354,7 +1359,7 @@ static void l2fwd(struct xsk_socket_info *xsk) 
		if (ret < 0)

			exit_with_error(-ret);

		complete_tx_l2fwd(xsk);

		if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {

		if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&xsk->tx)) {

			xsk->app_stats.tx_wakeup_sendtos++;

			kick_tx(xsk);

		}
@@ -1459,6 +1464,24 @@ static void enter_xsks_into_map(struct bpf_object *obj) 
	}

}



static void apply_setsockopt(struct xsk_socket_info *xsk)

{

	int sock_opt;



	if (!opt_busy_poll)

		return;



	sock_opt = 1;

	if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_PREFER_BUSY_POLL,

		       (void *)&sock_opt, sizeof(sock_opt)) < 0)

		exit_with_error(errno);



	sock_opt = 20;

	if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_BUSY_POLL,

		       (void *)&sock_opt, sizeof(sock_opt)) < 0)

		exit_with_error(errno);

}



int main(int argc, char **argv)

{

	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
@@ -1500,6 +1523,9 @@ int main(int argc, char **argv) 
	for (i = 0; i < opt_num_xsks; i++)

		xsks[num_socks++] = xsk_configure_socket(umem, rx, tx);



	for (i = 0; i < opt_num_xsks; i++)

		apply_setsockopt(xsks[i]);



	if (opt_bench == BENCH_TXONLY) {

		gen_eth_hdr_data();