GRO tests are timing dependent and can easily flake. This is partially mitigated in gro.sh by giving each subtest 3 chances to pass. However, this still flakes on some machines. Reduce the flakiness by:
- Bumping retries to 6. - Setting napi_defer_hard_irqs to 1 to reduce the chance that GRO is flushed prematurely. This also lets us reduce the gro_flush_timeout from 1ms to 100us.
Tested: Ran `gro.sh -t large` 1000 times. There were no failures with this change. Ran inside strace to increase flakiness.
Signed-off-by: Kevin Krakauer krakauer@google.com --- tools/testing/selftests/net/gro.sh | 4 ++-- tools/testing/selftests/net/setup_veth.sh | 3 ++- 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/net/gro.sh b/tools/testing/selftests/net/gro.sh index aabd6e5480b8..9e3f186bc2a1 100755 --- a/tools/testing/selftests/net/gro.sh +++ b/tools/testing/selftests/net/gro.sh @@ -18,10 +18,10 @@ run_test() { "--smac" "${CLIENT_MAC}" "--test" "${test}" "--verbose" )
setup_ns - # Each test is run 3 times to deflake, because given the receive timing, + # Each test is run 6 times to deflake, because given the receive timing, # not all packets that should coalesce will be considered in the same flow # on every try. - for tries in {1..3}; do + for tries in {1..6}; do # Actual test starts here ip netns exec $server_ns ./gro "${ARGS[@]}" "--rx" "--iface" "server" \ 1>>log.txt & diff --git a/tools/testing/selftests/net/setup_veth.sh b/tools/testing/selftests/net/setup_veth.sh index 1f78a87f6f37..eb3182066d12 100644 --- a/tools/testing/selftests/net/setup_veth.sh +++ b/tools/testing/selftests/net/setup_veth.sh @@ -11,7 +11,8 @@ setup_veth_ns() { local -r ns_mac="$4"
[[ -e /var/run/netns/"${ns_name}" ]] || ip netns add "${ns_name}" - echo 1000000 > "/sys/class/net/${ns_dev}/gro_flush_timeout" + echo 100000 > "/sys/class/net/${ns_dev}/gro_flush_timeout" + echo 1 > "/sys/class/net/${ns_dev}/napi_defer_hard_irqs" ip link set dev "${ns_dev}" netns "${ns_name}" mtu 65535 ip -netns "${ns_name}" link set dev "${ns_dev}" up