samples: bpf: Count syscalls in xdpsock

Categorise and record syscalls issued in the xdpsock sample app. The
categories recorded are:

  rx_empty_polls:    polls when the rx ring is empty
  fill_fail_polls:   polls when failed to get addr from fill ring
  copy_tx_sendtos:   sendtos issued for tx when copy mode enabled
  tx_wakeup_sendtos: sendtos issued when tx ring needs waking up
  opt_polls:         polls issued since the '-p' flag is set

Print the stats using '-a' on the xdpsock command line.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201002133612.31536-2-ciara.loftus@intel.com

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 4c5022e6479eb21339bb00aa2d62647fa98c4e44..ff119ede4ab19e526d43fcf29dd803165eb8d272 100644 (file)
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -79,6 +79,7 @@ static u16 opt_pkt_size = MIN_PKT_SIZE;
 static u32 opt_pkt_fill_pattern = 0x12345678;
 static bool opt_extra_stats;
 static bool opt_quiet;
+static bool opt_app_stats;
 static int opt_poll;
 static int opt_interval = 1;
 static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
@@ -110,6 +111,19 @@ struct xsk_ring_stats {
        unsigned long prev_tx_empty_npkts;
 };
 
+struct xsk_app_stats {
+       unsigned long rx_empty_polls;
+       unsigned long fill_fail_polls;
+       unsigned long copy_tx_sendtos;
+       unsigned long tx_wakeup_sendtos;
+       unsigned long opt_polls;
+       unsigned long prev_rx_empty_polls;
+       unsigned long prev_fill_fail_polls;
+       unsigned long prev_copy_tx_sendtos;
+       unsigned long prev_tx_wakeup_sendtos;
+       unsigned long prev_opt_polls;
+};
+
 struct xsk_umem_info {
        struct xsk_ring_prod fq;
        struct xsk_ring_cons cq;
@@ -123,6 +137,7 @@ struct xsk_socket_info {
        struct xsk_umem_info *umem;
        struct xsk_socket *xsk;
        struct xsk_ring_stats ring_stats;
+       struct xsk_app_stats app_stats;
        u32 outstanding_tx;
 };
 
@@ -189,6 +204,45 @@ static int xsk_get_xdp_stats(int fd, struct xsk_socket_info *xsk)
        return -EINVAL;
 }
 
+static void dump_app_stats(long dt)
+{
+       int i;
+
+       for (i = 0; i < num_socks && xsks[i]; i++) {
+               char *fmt = "%-18s %'-14.0f %'-14lu\n";
+               double rx_empty_polls_ps, fill_fail_polls_ps, copy_tx_sendtos_ps,
+                               tx_wakeup_sendtos_ps, opt_polls_ps;
+
+               rx_empty_polls_ps = (xsks[i]->app_stats.rx_empty_polls -
+                                       xsks[i]->app_stats.prev_rx_empty_polls) * 1000000000. / dt;
+               fill_fail_polls_ps = (xsks[i]->app_stats.fill_fail_polls -
+                                       xsks[i]->app_stats.prev_fill_fail_polls) * 1000000000. / dt;
+               copy_tx_sendtos_ps = (xsks[i]->app_stats.copy_tx_sendtos -
+                                       xsks[i]->app_stats.prev_copy_tx_sendtos) * 1000000000. / dt;
+               tx_wakeup_sendtos_ps = (xsks[i]->app_stats.tx_wakeup_sendtos -
+                                       xsks[i]->app_stats.prev_tx_wakeup_sendtos)
+                                                                               * 1000000000. / dt;
+               opt_polls_ps = (xsks[i]->app_stats.opt_polls -
+                                       xsks[i]->app_stats.prev_opt_polls) * 1000000000. / dt;
+
+               printf("\n%-18s %-14s %-14s\n", "", "calls/s", "count");
+               printf(fmt, "rx empty polls", rx_empty_polls_ps, xsks[i]->app_stats.rx_empty_polls);
+               printf(fmt, "fill fail polls", fill_fail_polls_ps,
+                                                       xsks[i]->app_stats.fill_fail_polls);
+               printf(fmt, "copy tx sendtos", copy_tx_sendtos_ps,
+                                                       xsks[i]->app_stats.copy_tx_sendtos);
+               printf(fmt, "tx wakeup sendtos", tx_wakeup_sendtos_ps,
+                                                       xsks[i]->app_stats.tx_wakeup_sendtos);
+               printf(fmt, "opt polls", opt_polls_ps, xsks[i]->app_stats.opt_polls);
+
+               xsks[i]->app_stats.prev_rx_empty_polls = xsks[i]->app_stats.rx_empty_polls;
+               xsks[i]->app_stats.prev_fill_fail_polls = xsks[i]->app_stats.fill_fail_polls;
+               xsks[i]->app_stats.prev_copy_tx_sendtos = xsks[i]->app_stats.copy_tx_sendtos;
+               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;
+       }
+}
+
 static void dump_stats(void)
 {
        unsigned long now = get_nsecs();
@@ -198,7 +252,7 @@ static void dump_stats(void)
        prev_time = now;
 
        for (i = 0; i < num_socks && xsks[i]; i++) {
-               char *fmt = "%-15s %'-11.0f %'-11lu\n";
+               char *fmt = "%-18s %'-14.0f %'-14lu\n";
                double rx_pps, tx_pps, dropped_pps, rx_invalid_pps, full_pps, fill_empty_pps,
                        tx_invalid_pps, tx_empty_pps;
 
@@ -211,7 +265,7 @@ static void dump_stats(void)
                print_benchmark(false);
                printf("\n");
 
-               printf("%-15s %-11s %-11s %-11.2f\n", "", "pps", "pkts",
+               printf("%-18s %-14s %-14s %-14.2f\n", "", "pps", "pkts",
                       dt / 1000000000.);
                printf(fmt, "rx", rx_pps, xsks[i]->ring_stats.rx_npkts);
                printf(fmt, "tx", tx_pps, xsks[i]->ring_stats.tx_npkts);
@@ -270,6 +324,9 @@ static void dump_stats(void)
                        }
                }
        }
+
+       if (opt_app_stats)
+               dump_app_stats(dt);
 }
 
 static bool is_benchmark_done(void)
@@ -708,6 +765,17 @@ static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem,
        if (ret)
                exit_with_error(-ret);
 
+       xsk->app_stats.rx_empty_polls = 0;
+       xsk->app_stats.fill_fail_polls = 0;
+       xsk->app_stats.copy_tx_sendtos = 0;
+       xsk->app_stats.tx_wakeup_sendtos = 0;
+       xsk->app_stats.opt_polls = 0;
+       xsk->app_stats.prev_rx_empty_polls = 0;
+       xsk->app_stats.prev_fill_fail_polls = 0;
+       xsk->app_stats.prev_copy_tx_sendtos = 0;
+       xsk->app_stats.prev_tx_wakeup_sendtos = 0;
+       xsk->app_stats.prev_opt_polls = 0;
+
        return xsk;
 }
 
@@ -735,6 +803,7 @@ static struct option long_options[] = {
        {"tx-pkt-pattern", required_argument, 0, 'P'},
        {"extra-stats", no_argument, 0, 'x'},
        {"quiet", no_argument, 0, 'Q'},
+       {"app-stats", no_argument, 0, 'a'},
        {0, 0, 0, 0}
 };
 
@@ -771,6 +840,7 @@ static void usage(const char *prog)
                "  -P, --tx-pkt-pattern=nPacket fill pattern. Default: 0x%x\n"
                "  -x, --extra-stats    Display extra statistics.\n"
                "  -Q, --quiet          Do not display any stats.\n"
+               "  -a, --app-stats      Display application (syscall) statistics.\n"
                "\n";
        fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,
                opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
@@ -786,7 +856,7 @@ 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:xQ",
+               c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQa",
                                long_options, &option_index);
                if (c == -1)
                        break;
@@ -873,6 +943,9 @@ static void parse_command_line(int argc, char **argv)
                case 'Q':
                        opt_quiet = 1;
                        break;
+               case 'a':
+                       opt_app_stats = 1;
+                       break;
                default:
                        usage(basename(argv[0]));
                }
@@ -923,8 +996,10 @@ static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
         * is driven by the NAPI loop. So as an optimization, we do not have to call
         * sendto() all the time in zero-copy mode for l2fwd.
         */
-       if (opt_xdp_bind_flags & XDP_COPY)
+       if (opt_xdp_bind_flags & XDP_COPY) {
+               xsk->app_stats.copy_tx_sendtos++;
                kick_tx(xsk);
+       }
 
        ndescs = (xsk->outstanding_tx > opt_batch_size) ? opt_batch_size :
                xsk->outstanding_tx;
@@ -939,8 +1014,10 @@ 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 (xsk_ring_prod__needs_wakeup(&umem->fq)) {
+                               xsk->app_stats.fill_fail_polls++;
                                ret = poll(fds, num_socks, opt_timeout);
+                       }
                        ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
                }
 
@@ -964,8 +1041,10 @@ static inline void complete_tx_only(struct xsk_socket_info *xsk,
        if (!xsk->outstanding_tx)
                return;
 
-       if (!opt_need_wakeup || xsk_ring_prod__needs_wakeup(&xsk->tx))
+       if (!opt_need_wakeup || xsk_ring_prod__needs_wakeup(&xsk->tx)) {
+               xsk->app_stats.tx_wakeup_sendtos++;
                kick_tx(xsk);
+       }
 
        rcvd = xsk_ring_cons__peek(&xsk->umem->cq, batch_size, &idx);
        if (rcvd > 0) {
@@ -983,8 +1062,10 @@ static void rx_drop(struct xsk_socket_info *xsk, struct pollfd *fds)
 
        rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
        if (!rcvd) {
-               if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq))
+               if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+                       xsk->app_stats.rx_empty_polls++;
                        ret = poll(fds, num_socks, opt_timeout);
+               }
                return;
        }
 
@@ -992,8 +1073,10 @@ static void rx_drop(struct xsk_socket_info *xsk, struct pollfd *fds)
        while (ret != rcvd) {
                if (ret < 0)
                        exit_with_error(-ret);
-               if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq))
+               if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+                       xsk->app_stats.fill_fail_polls++;
                        ret = poll(fds, num_socks, opt_timeout);
+               }
                ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
        }
 
@@ -1026,6 +1109,8 @@ static void rx_drop_all(void)
 
        for (;;) {
                if (opt_poll) {
+                       for (i = 0; i < num_socks; i++)
+                               xsks[i]->app_stats.opt_polls++;
                        ret = poll(fds, num_socks, opt_timeout);
                        if (ret <= 0)
                                continue;
@@ -1106,6 +1191,8 @@ static void tx_only_all(void)
                int batch_size = get_batch_size(pkt_cnt);
 
                if (opt_poll) {
+                       for (i = 0; i < num_socks; i++)
+                               xsks[i]->app_stats.opt_polls++;
                        ret = poll(fds, num_socks, opt_timeout);
                        if (ret <= 0)
                                continue;
@@ -1137,8 +1224,10 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
 
        rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
        if (!rcvd) {
-               if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq))
+               if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+                       xsk->app_stats.rx_empty_polls++;
                        ret = poll(fds, num_socks, opt_timeout);
+               }
                return;
        }
 
@@ -1147,8 +1236,10 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
                if (ret < 0)
                        exit_with_error(-ret);
                complete_tx_l2fwd(xsk, fds);
-               if (xsk_ring_prod__needs_wakeup(&xsk->tx))
+               if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {
+                       xsk->app_stats.tx_wakeup_sendtos++;
                        kick_tx(xsk);
+               }
                ret = xsk_ring_prod__reserve(&xsk->tx, rcvd, &idx_tx);
        }
 
@@ -1186,6 +1277,8 @@ static void l2fwd_all(void)
 
        for (;;) {
                if (opt_poll) {
+                       for (i = 0; i < num_socks; i++)
+                               xsks[i]->app_stats.opt_polls++;
                        ret = poll(fds, num_socks, opt_timeout);
                        if (ret <= 0)
                                continue;