Re: [RFC PATCH v2 10/10] selftests: add functionals test for UDP GRO

[Paolo Abeni <pabeni@redhat.com>]

On Sun, 2018-10-21 at 16:09 -0400, Willem de Bruijn wrote:
> On Fri, Oct 19, 2018 at 10:31 AM Paolo Abeni <pabeni@redhat.com> wrote:
> > 
> > Extends the existing udp programs to allow checking for proper
> > GRO aggregation/GSO size, and run the tests via a shell script, using
> > a veth pair with XDP program attached to trigger the GRO code path.
> > 
> > Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> > ---
> >  tools/testing/selftests/net/Makefile          |   2 +-
> >  tools/testing/selftests/net/udpgro.sh         | 144 ++++++++++++++++++
> >  tools/testing/selftests/net/udpgro_bench.sh   |   8 +-
> >  tools/testing/selftests/net/udpgso_bench.sh   |   2 +-
> >  tools/testing/selftests/net/udpgso_bench_rx.c | 125 +++++++++++++--
> >  tools/testing/selftests/net/udpgso_bench_tx.c |  22 ++-
> >  6 files changed, 281 insertions(+), 22 deletions(-)
> >  create mode 100755 tools/testing/selftests/net/udpgro.sh
> > 
> > diff --git a/tools/testing/selftests/net/udpgro.sh b/tools/testing/selftests/net/udpgro.sh
> > +       run_test "no GRO chk cmsg" "${ipv4_args} -M 10 -s 1400" "-4 -n 10 -l 1400 -S -1"
> > +       run_test "no GRO chk cmsg" "${ipv6_args} -M 10 -s 1400" "-n 10 -l 1400 -S -1"
> 
> why expected segment size -1 in these two?

I was unable to come up with a self-explaining option name/syntax. '-1' 
really means 'no UDP_SEGMENT cmsg'. Since the receiver did not enable
UDP_GRO, should not receive such cmsg.
> 
> > diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c
> >  static void usage(const char *filepath)
> >  {
> > -       error(1, 0, "Usage: %s [-46cmStuz] [-C cpu] [-D dst ip] [-l secs] [-p port] [-s sendsize]",
> > +       error(1, 0, "Usage: %s [-46cmtuz] [-C cpu] [-D dst ip] [-l secs] [-m messagenr] [-p port] [-s sendsize] [-S gsosize]",
> >                     filepath);
> 
> missing -M

Will add in next iteration.

Additional node: in the current test implementation, 'no GRO chk cmsg'
sometimes wrongly returns a failure. I'll try to address it in the next
iteration (it's a test issue in the code I added, not a kernel one).

Cheers,

Paolo