On Wed, Jul 31, 2024 at 7:25 PM Breno Leitao [off-list ref] wrote:

Hello Paolo,

On Tue, Jul 30, 2024 at 11:38:38AM +0200, Paolo Abeni wrote:

quoted

Could you please benchmark such scenario before and after this patch?

I've tested it on a 18-core Xeon D-2191A host, and I haven't found any
different in either TX/RX in TCP or UDP. At the same time, I must admit
that I have very low confidence in my tests.

I run the following tests for 10x on the same machine, just changing my
patch, and I getting the simple average of these 10 iterations. This is
what I am doing for TCP and UDP:

TCP:
        # iperf -s &
        # iperf -u -c localhost

        Output: 16.5 Gbits/sec

UDP:
        # iperf -s -u &
        # iperf -u -c localhost

        Output: 1.05 Mbits/sec

I don't know how to explain why UDP numbers are so low. I am happy to
run different tests, if you have any other recommendation.

I think the iperf tool uses '-b 1' as default, which is explained in
the man page:
CLIENT SPECIFIC OPTIONS
       -b, --bandwidth n[kmgKMG][,n[kmgKMG]] | n[kmgKMG]pps
              set  target  bandwidth  to  n  bits/sec  (default  1
Mbit/sec)  or  n  packets per sec. This may be used with TCP or UDP.
Optionally, for variable loads, use format of
              mean,standard deviation

So, if you try the parameter like '-b 40MB', it will reach around
40MB/sec speed.

If I were you, I could try the following way:
1) iperf3 -s
2) iperf3 -u -c 127.0.0.1 -b 0 -l 64

Hope it can help you:)

Thanks,
Jason

--breno