RE: [PATCH linux-next 3/3] selftests: net: udpgso_bench_rx: Fix packet number exceptions

From: Willem de Bruijn
Date: Mon Apr 17 2023 - 11:28:40 EST


Yang Yang wrote:
> From: Zhang Yunkai (CGEL ZTE) <zhang.yunkai@xxxxxxxxxx>
>
> The -n parameter is confusing and seems to only affect the frequency of
> determining whether the time reaches 1s.

This statement seems irrelevant to this patch.

Is the point that cfg_expected_pkt_nr is tested in do_flush_udp to
stop reading, but not in the caller of that function, do_recv, to
break out of the loop? That's a fair point and may deserve a fix.

> However, the final print of the
> program is the number of messages expected to be received, which is always
> 0.
>
> bash# udpgso_bench_rx -4 -n 100
> bash# udpgso_bench_tx -l 1 -4 -D "$DST"
> udpgso_bench_rx: wrong packet number! got 0, expected 100
>
> This is because the packets are always cleared after print.

This looks good to me. Would be a fix to the commit that introduced
that wrong packet number branch, commit 3327a9c46352
("selftests: add functionals test for UDP GRO").
>
> Signed-off-by: Zhang Yunkai (CGEL ZTE) <zhang.yunkai@xxxxxxxxxx>
> Reviewed-by: xu xin (CGEL ZTE) <xu.xin16@xxxxxxxxxx>
> Reviewed-by: Yang Yang (CGEL ZTE) <yang.yang29@xxxxxxxxxx>
> Cc: Xuexin Jiang (CGEL ZTE) <jiang.xuexin@xxxxxxxxxx>
> ---
> tools/testing/selftests/net/udpgso_bench_rx.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/net/udpgso_bench_rx.c b/tools/testing/selftests/net/udpgso_bench_rx.c
> index 784e88b31f7d..b66bb53af19f 100644
> --- a/tools/testing/selftests/net/udpgso_bench_rx.c
> +++ b/tools/testing/selftests/net/udpgso_bench_rx.c
> @@ -50,7 +50,7 @@ static int cfg_rcv_timeout_ms;
> static struct sockaddr_storage cfg_bind_addr;
>
> static bool interrupted;
> -static unsigned long packets, bytes;
> +static unsigned long packets, total_packets, bytes;
>
> static void sigint_handler(int signum)
> {
> @@ -405,6 +405,7 @@ static void do_recv(void)
> "%s rx: %6lu MB/s %8lu calls/s\n",
> cfg_tcp ? "tcp" : "udp",
> bytes >> 20, packets);
> + total_packets += packets;
> bytes = packets = 0;
> treport = tnow + 1000;
> }
> @@ -415,7 +416,7 @@ static void do_recv(void)
>
> if (cfg_expected_pkt_nr && (packets != cfg_expected_pkt_nr))
> error(1, 0, "wrong packet number! got %ld, expected %d\n",
> - packets, cfg_expected_pkt_nr);
> + total_packets + packets, cfg_expected_pkt_nr);
>
> if (close(fd))
> error(1, errno, "close");
> --
> 2.15.2