selftests: net: Lower threshold on debug kernels for big_tcp_tunnels.sh

Debug kernels on upstream CI runners run slower and generate fewer BIG
TCP packets, making the test flaky on upstream CI runners. Lower the
default threshold for those kernels.

Fixes: 5cb53743e1ff ("selftests: net: Add a test for BIG TCP in UDP tunnels")
Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260822120308.1165200-3-alice.kernel@fastmail.im
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/big_tcp_tunnels.sh b/tools/testing/selftests/net/big_tcp_tunnels.sh
index 9b7d0456bcc1616917013c8cdecd06cf0e142d2f..e0b41f394ebb5c75e63b2aae030980b1b919e57e 100755 (executable)
--- a/tools/testing/selftests/net/big_tcp_tunnels.sh
+++ b/tools/testing/selftests/net/big_tcp_tunnels.sh
@@ -17,11 +17,18 @@ CLIENT_IP6="2001:db8::1:2"
 CLIENT_IP4_TUN="192.168.2.2"
 CLIENT_IP6_TUN="2001:db8::2:2"
 
-: "${PACKETS_THRESHOLD:=1000}"
-
 # Kselftest framework requirement - SKIP code is 4.
 ksft_skip=4
 
+if [ -z "$PACKETS_THRESHOLD" ]; then
+       if [ "$KSFT_MACHINE_SLOW" = yes ]; then
+               echo 'Debug kernel detected, lowering the default threshold'
+               PACKETS_THRESHOLD=100
+       else
+               PACKETS_THRESHOLD=1000
+       fi
+fi
+
 setup() {
        ip netns add "$SERVER_NS"
        ip netns add "$CLIENT_NS"