On Tue, Jul 24, 2018 at 06:35:35PM +0300, Konstantin Khorenko wrote:

Hi Marcelo,

pity to abandon Oleg's attempt to avoid high order allocations and use
flex_array instead, so i tried to do the performance measurements with
options you kindly suggested.

Nice, thanks!

...

As we can see single stream tests do not show any noticeable degradation,
and SCTP_*_MANY tests spread decreased significantly when -S/-s options are used,
but still too big to consider the performance test pass or fail.

Can you please advise anything else to try - to decrease the dispersion rate -

In addition, you can try also using a veth tunnel or reducing lo mtu
down to 1500, and also make use of sctp tests (need to be after the --
) option -m 1452.  These will alleaviate issues with cwnd handling
that happen on loopback due to the big MTU and minimize issues with
rwnd/buffer size too.

Even with -S, -s, -m and the lower MTU, it is usual to see some
fluctuation, but not that much.

or can we just consider values are fine and i'm reworking the patch according
to your comment about sctp_stream_in(asoc, sid)/sctp_stream_in_ptr(stream, sid)
and that's it?

Ok, thanks. It seems so, yes.

  Marcelo