RE: [PATCH iwl-next,v2 1/2] selftests/bpf: xdp_hw_metadata reduce sleep interval

From: John Fastabend
Date: Fri Mar 01 2024 - 12:24:12 EST


Song Yoong Siang wrote:
> In current ping-pong design, xdp_hw_metadata will wait until the packet
> transmition 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 able to support periodic packets with shorter interval.
> 10us * 500 = 5ms should be enough for packet transmission and status
> retrival.
>
> Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx>
> ---
> tools/testing/selftests/bpf/xdp_hw_metadata.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> index 878d68db0325..bdf5d8180067 100644
> --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
> +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> @@ -480,7 +480,7 @@ static int verify_metadata(struct xsk *rx_xsk, int rxq, int server_fd, clockid_t
> for (int j = 0; j < 500; j++) {
> if (complete_tx(xsk, clock_id))
> break;
> - usleep(10*1000);
> + usleep(10);
> }
> }
> }
> --
> 2.34.1
>

Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>