selftests/bpf: xdp_hw_metadata reduce sleep interval

In current ping-pong design, xdp_hw_metadata will wait until the packet
transmission completely done, then only start to receive the next packet.

The current sleep interval is 10ms, which is unnecessary large. Typically,
a NIC does not need such a long time to transmit a packet. Furthermore,
during this 10ms sleep time, the app is unable to receive incoming packets.

Therefore, this commit reduce sleep interval to 10us, so that
xdp_hw_metadata is able to support periodic packets with shorter interval.
10us * 500 = 5ms should be enough for packet transmission and status
retrieval.

Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20240303083225.1184165-2-yoong.siang.song@intel.com

diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 878d68db0325673c0fa16ccefe583ea283903f88..bdf5d8180067f8d2bfeb2ad520aae86134876a10 100644 (file)
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -480,7 +480,7 @@ peek:
                                        for (int j = 0; j < 500; j++) {
                                                if (complete_tx(xsk, clock_id))
                                                        break;
-                                               usleep(10*1000);
+                                               usleep(10);
                                        }
                                }
                        }