[X][B][SRU][PATCH 0/2] selftests/net: make psock_fanout become more reliable

[Po-Hsu Lin]

== SRU Justification ==
The psock_fanout test is not very stable, stress tests shows a high
fail rate here:
  * X - 44 failures out of 100, with 4.4 kernel on a KVM node
  * B - 33 failures out of 100, with 4.15 kernel on a KVM node

This is because of the unrelated background traffic which should be
filtered out.

Also, the error message, "ERROR: incorrect queue lengths", is a bit
misleading. You can see this even the test has passed, it's not the
real cause of the failure. This message has been changed to "warning:
incorrect queue lengths" later.

== Fix ==
1. 2e7a7217 (selftests/net: cleanup unused parameter in psock_fanout)
2. cc30c93f (selftests/net: ignore background traffic in psock_fanout)

The first patch has already landed in Bionic, and it can be
cherry-picked into Xenial.

The second one needs to be backported to Xenial, but it can be applied
to Bionic with git am -C2.

== Test ==
Patch tested directly on 4.4 / 4.15 KVM nodes.

Stress tested 100 times with:
    i=0
    for idx in $(seq 1 100)
    do
        sudo ./psock_fanout &> /dev/null
        [ $? != 0 ] && i=$((i+1))
    done
    echo $i

All tests have passed without any failure.

== Regression Potential ==
Low, change limited to testing tools, not affecting actual kernel
functionality.

Mike Maloney (1):
  selftests/net: cleanup unused parameter in psock_fanout

Willem de Bruijn (1):
  selftests/net: ignore background traffic in psock_fanout

 tools/testing/selftests/net/in_netns.sh       | 23 ++++++++++++
 tools/testing/selftests/net/psock_fanout.c    | 51 ++++++++++++++++++---------
 tools/testing/selftests/net/run_afpackettests |  4 +--
 3 files changed, 60 insertions(+), 18 deletions(-)
 create mode 100755 tools/testing/selftests/net/in_netns.sh

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2.7.4