[PATCH net] selftests/net: packetdrill: increase timing tolerance in debug mode

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

From: Willem de Bruijn <willemb@google.com>

Some packetdrill tests are flaky in debug mode. As discussed, increase
tolerance.

We have been doing this for debug builds outside ksft too.

Previous setting was 10000. A manual 50 runs in virtme-ng showed two
failures that needed 12000. To be on the safe side, Increase to 14000.

Link: https://lore.kernel.org/netdev/Zuhhe4-MQHd3EkfN@mini-arch/
Fixes: 1e42f73fd3c2 ("selftests/net: packetdrill: import tcp/zerocopy")
Reported-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
 tools/testing/selftests/net/packetdrill/ksft_runner.sh | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/packetdrill/ksft_runner.sh b/tools/testing/selftests/net/packetdrill/ksft_runner.sh
index 7478c0c0c9aa..4071c133f29e 100755
--- a/tools/testing/selftests/net/packetdrill/ksft_runner.sh
+++ b/tools/testing/selftests/net/packetdrill/ksft_runner.sh
@@ -30,12 +30,17 @@ if [ -z "$(which packetdrill)" ]; then
 	exit "$KSFT_SKIP"
 fi
 
+declare -a optargs
+if [[ -n "${KSFT_MACHINE_SLOW}" ]]; then
+	optargs+=('--tolerance_usecs=14000')
+fi
+
 ktap_print_header
 ktap_set_plan 2
 
-unshare -n packetdrill ${ipv4_args[@]} $(basename $script) > /dev/null \
+unshare -n packetdrill ${ipv4_args[@]} ${optargs[@]} $(basename $script) > /dev/null \
 	&& ktap_test_pass "ipv4" || ktap_test_fail "ipv4"
-unshare -n packetdrill ${ipv6_args[@]} $(basename $script) > /dev/null \
+unshare -n packetdrill ${ipv6_args[@]} ${optargs[@]} $(basename $script) > /dev/null \
 	&& ktap_test_pass "ipv6" || ktap_test_fail "ipv6"
 
 ktap_finished
-- 
2.46.0.662.g92d0881bb0-goog