On Thu, Nov 19, 2020 at 9:33 AM Björn Töpel <bjorn.topel@xxxxxxxxx> wrote:
>
> From: Björn Töpel <bjorn.topel@xxxxxxxxx>
>
> 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: Björn Töpel <bjorn.topel@xxxxxxxxx>
> ---
> samples/bpf/xdpsock_user.c | 40 +++++++++++++++++++++++++++++++-------
> 1 file changed, 33 insertions(+), 7 deletions(-)
Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
> index 24aa7511c4c8..cb1eaee8a32b 100644
> --- a/samples/bpf/xdpsock_user.c
> +++ b/samples/bpf/xdpsock_user.c
> @@ -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);
> }
> @@ -1177,7 +1182,7 @@ 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);
> }
> @@ -1188,7 +1193,7 @@ 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);
> }
> @@ -1340,7 +1345,7 @@ 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);
> }
> @@ -1353,7 +1358,7 @@ 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);
> }
> @@ -1458,6 +1463,24 @@ 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};
> @@ -1499,6 +1522,9 @@ 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();
>
> --
> 2.27.0
>
