From: Matthieu Baerts (NGI0) Date: Wed, 27 May 2026 12:11:34 +0000 (+1000) Subject: selftests: mptcp: simult_flows: disable GSO X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f1fd73c2204d958edf688aa25f5bc3db8d36c9c;p=thirdparty%2Flinux.git selftests: mptcp: simult_flows: disable GSO Netem is used to apply a rate limit, and its 'limit' option is per packet. Disable GSO on both sides to work with packets of a specific size. That increases the number of packets, but stabilise the throughput. As a consequence, limits are more adapted, and the bufferbloat is reduced. Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260527-net-mptcp-sft-bufferbloat-exit-v1-1-9afc4e742090@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/tools/testing/selftests/net/mptcp/simult_flows.sh b/tools/testing/selftests/net/mptcp/simult_flows.sh index d11a8b949aab5..345cf200c653f 100755 --- a/tools/testing/selftests/net/mptcp/simult_flows.sh +++ b/tools/testing/selftests/net/mptcp/simult_flows.sh @@ -76,13 +76,13 @@ setup() ip -net "$ns1" addr add 10.0.1.1/24 dev ns1eth1 ip -net "$ns1" addr add dead:beef:1::1/64 dev ns1eth1 nodad - ip -net "$ns1" link set ns1eth1 up mtu 1500 + ip -net "$ns1" link set ns1eth1 up mtu 1500 gso_max_segs 0 ip -net "$ns1" route add default via 10.0.1.2 ip -net "$ns1" route add default via dead:beef:1::2 ip -net "$ns1" addr add 10.0.2.1/24 dev ns1eth2 ip -net "$ns1" addr add dead:beef:2::1/64 dev ns1eth2 nodad - ip -net "$ns1" link set ns1eth2 up mtu 1500 + ip -net "$ns1" link set ns1eth2 up mtu 1500 gso_max_segs 0 ip -net "$ns1" route add default via 10.0.2.2 metric 101 ip -net "$ns1" route add default via dead:beef:2::2 metric 101 @@ -91,21 +91,21 @@ setup() ip -net "$ns2" addr add 10.0.1.2/24 dev ns2eth1 ip -net "$ns2" addr add dead:beef:1::2/64 dev ns2eth1 nodad - ip -net "$ns2" link set ns2eth1 up mtu 1500 + ip -net "$ns2" link set ns2eth1 up mtu 1500 gso_max_segs 0 ip -net "$ns2" addr add 10.0.2.2/24 dev ns2eth2 ip -net "$ns2" addr add dead:beef:2::2/64 dev ns2eth2 nodad - ip -net "$ns2" link set ns2eth2 up mtu 1500 + ip -net "$ns2" link set ns2eth2 up mtu 1500 gso_max_segs 0 ip -net "$ns2" addr add 10.0.3.2/24 dev ns2eth3 ip -net "$ns2" addr add dead:beef:3::2/64 dev ns2eth3 nodad - ip -net "$ns2" link set ns2eth3 up mtu 1500 + ip -net "$ns2" link set ns2eth3 up mtu 1500 gso_max_segs 0 ip netns exec "$ns2" sysctl -q net.ipv4.ip_forward=1 ip netns exec "$ns2" sysctl -q net.ipv6.conf.all.forwarding=1 ip -net "$ns3" addr add 10.0.3.3/24 dev ns3eth1 ip -net "$ns3" addr add dead:beef:3::3/64 dev ns3eth1 nodad - ip -net "$ns3" link set ns3eth1 up mtu 1500 + ip -net "$ns3" link set ns3eth1 up mtu 1500 gso_max_segs 0 ip -net "$ns3" route add default via 10.0.3.2 ip -net "$ns3" route add default via dead:beef:3::2