samples/bpf: xdpsock: Add option to specify number of packets to send

Use '-C' or '--tx-pkt-count' to specify number of packets to send.
If it is not specified, the application sends packets forever. If packet
count is not a multiple of batch size, last batch sent is less than the
batch size.

Signed-off-by: Jay Jayatheerthan <jay.jayatheerthan@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191220085530.4980-5-jay.jayatheerthan@intel.com

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 1ba3e7142f39f786ebc8efad613594e1fb4d0d94..f96ce3055d46aaecb01e57fc4a118094ff5fef13 100644 (file)
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -68,6 +68,7 @@ static unsigned long opt_duration;
 static unsigned long start_time;
 static bool benchmark_done;
 static u32 opt_batch_size = 64;
+static int opt_pkt_count;
 static int opt_poll;
 static int opt_interval = 1;
 static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
@@ -392,6 +393,7 @@ static struct option long_options[] = {
        {"force", no_argument, 0, 'F'},
        {"duration", required_argument, 0, 'd'},
        {"batch-size", required_argument, 0, 'b'},
+       {"tx-pkt-count", required_argument, 0, 'C'},
        {0, 0, 0, 0}
 };
 
@@ -420,6 +422,8 @@ static void usage(const char *prog)
                "                       Default: forever.\n"
                "  -b, --batch-size=n   Batch size for sending or receiving\n"
                "                       packets. Default: %d\n"
+               "  -C, --tx-pkt-count=n Number of packets to send.\n"
+               "                       Default: Continuous packets.\n"
                "\n";
        fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,
                opt_batch_size);
@@ -433,7 +437,7 @@ static void parse_command_line(int argc, char **argv)
        opterr = 0;
 
        for (;;) {
-               c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:",
+               c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:",
                                long_options, &option_index);
                if (c == -1)
                        break;
@@ -498,6 +502,9 @@ static void parse_command_line(int argc, char **argv)
                case 'b':
                        opt_batch_size = atoi(optarg);
                        break;
+               case 'C':
+                       opt_pkt_count = atoi(optarg);
+                       break;
                default:
                        usage(basename(argv[0]));
                }
@@ -574,7 +581,8 @@ static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
        }
 }
 
-static inline void complete_tx_only(struct xsk_socket_info *xsk)
+static inline void complete_tx_only(struct xsk_socket_info *xsk,
+                                   int batch_size)
 {
        unsigned int rcvd;
        u32 idx;
@@ -585,7 +593,7 @@ static inline void complete_tx_only(struct xsk_socket_info *xsk)
        if (!opt_need_wakeup || xsk_ring_prod__needs_wakeup(&xsk->tx))
                kick_tx(xsk);
 
-       rcvd = xsk_ring_cons__peek(&xsk->umem->cq, opt_batch_size, &idx);
+       rcvd = xsk_ring_cons__peek(&xsk->umem->cq, batch_size, &idx);
        if (rcvd > 0) {
                xsk_ring_cons__release(&xsk->umem->cq, rcvd);
                xsk->outstanding_tx -= rcvd;
@@ -657,34 +665,62 @@ static void rx_drop_all(void)
        }
 }
 
-static void tx_only(struct xsk_socket_info *xsk, u32 frame_nb)
+static void tx_only(struct xsk_socket_info *xsk, u32 frame_nb, int batch_size)
 {
        u32 idx;
        unsigned int i;
 
-       while (xsk_ring_prod__reserve(&xsk->tx, opt_batch_size, &idx) <
-                                     opt_batch_size) {
-               complete_tx_only(xsk);
+       while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) <
+                                     batch_size) {
+               complete_tx_only(xsk, batch_size);
        }
 
-       for (i = 0; i < opt_batch_size; i++) {
+       for (i = 0; i < batch_size; i++) {
                struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx,
                                                                  idx + i);
                tx_desc->addr = (frame_nb + i) << XSK_UMEM__DEFAULT_FRAME_SHIFT;
                tx_desc->len = sizeof(pkt_data) - 1;
        }
 
-       xsk_ring_prod__submit(&xsk->tx, opt_batch_size);
-       xsk->outstanding_tx += opt_batch_size;
-       frame_nb += opt_batch_size;
+       xsk_ring_prod__submit(&xsk->tx, batch_size);
+       xsk->outstanding_tx += batch_size;
+       frame_nb += batch_size;
        frame_nb %= NUM_FRAMES;
-       complete_tx_only(xsk);
+       complete_tx_only(xsk, batch_size);
+}
+
+static inline int get_batch_size(int pkt_cnt)
+{
+       if (!opt_pkt_count)
+               return opt_batch_size;
+
+       if (pkt_cnt + opt_batch_size <= opt_pkt_count)
+               return opt_batch_size;
+
+       return opt_pkt_count - pkt_cnt;
+}
+
+static void complete_tx_only_all(void)
+{
+       bool pending;
+       int i;
+
+       do {
+               pending = false;
+               for (i = 0; i < num_socks; i++) {
+                       if (xsks[i]->outstanding_tx) {
+                               complete_tx_only(xsks[i], opt_batch_size);
+                               pending = !!xsks[i]->outstanding_tx;
+                       }
+               }
+       } while (pending);
 }
 
 static void tx_only_all(void)
 {
        struct pollfd fds[MAX_SOCKS] = {};
        u32 frame_nb[MAX_SOCKS] = {};
+       int pkt_cnt = 0;
        int i, ret;
 
        for (i = 0; i < num_socks; i++) {
@@ -692,7 +728,9 @@ static void tx_only_all(void)
                fds[0].events = POLLOUT;
        }
 
-       for (;;) {
+       while ((opt_pkt_count && pkt_cnt < opt_pkt_count) || !opt_pkt_count) {
+               int batch_size = get_batch_size(pkt_cnt);
+
                if (opt_poll) {
                        ret = poll(fds, num_socks, opt_timeout);
                        if (ret <= 0)
@@ -703,11 +741,16 @@ static void tx_only_all(void)
                }
 
                for (i = 0; i < num_socks; i++)
-                       tx_only(xsks[i], frame_nb[i]);
+                       tx_only(xsks[i], frame_nb[i], batch_size);
+
+               pkt_cnt += batch_size;
 
                if (benchmark_done)
                        break;
        }
+
+       if (opt_pkt_count)
+               complete_tx_only_all();
 }
 
 static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
@@ -900,6 +943,8 @@ int main(int argc, char **argv)
        else
                l2fwd_all();
 
+       benchmark_done = true;
+
        pthread_join(pt, NULL);
 
        xdpsock_cleanup();