The pmtu test takes nearly an hour when run on a debug kernel (10min on a normal kernel, so the debug slow down is quite significant). NIPA tries to ensure all results are delivered by a certain deadline so this prevents it from retrying the test in case of a flake.
Looks like one of the slowest operations in the test is calling out to ./openvswitch/ovs-dpctl.py to remove potential leftover OvS interfaces. Check whether the interfaces exist in the first place in sysfs, since it can be done directly in bash it is very fast.
This should save us around 20-30% of the test runtime.
Signed-off-by: Jakub Kicinski kuba@kernel.org --- tools/testing/selftests/net/pmtu.sh | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh index 88e914c4eef9..a3323c21f001 100755 --- a/tools/testing/selftests/net/pmtu.sh +++ b/tools/testing/selftests/net/pmtu.sh @@ -1089,10 +1089,11 @@ cleanup() {
cleanup_all_ns
- ip link del veth_A-C 2>/dev/null - ip link del veth_A-R1 2>/dev/null - cleanup_del_ovs_internal - cleanup_del_ovs_vswitchd + [ -e "/sys/class/net/veth_A-C" ] && ip link del veth_A-C + [ -e "/sys/class/net/veth_A-R1" ] && ip link del veth_A-R1 + [ -e "/sys/class/net/ovs_br0" ] && cleanup_del_ovs_internal + [ -e "/sys/class/net/ovs_br0" ] && cleanup_del_ovs_vswitchd + rm -f "$tmpoutfile" }
On Sat, Sep 06, 2025 at 02:45:35PM -0700, Jakub Kicinski wrote:
The pmtu test takes nearly an hour when run on a debug kernel (10min on a normal kernel, so the debug slow down is quite significant). NIPA tries to ensure all results are delivered by a certain deadline so this prevents it from retrying the test in case of a flake.
Looks like one of the slowest operations in the test is calling out to ./openvswitch/ovs-dpctl.py to remove potential leftover OvS interfaces. Check whether the interfaces exist in the first place in sysfs, since it can be done directly in bash it is very fast.
This should save us around 20-30% of the test runtime.
Signed-off-by: Jakub Kicinski kuba@kernel.org
It would be interesting to know why this is so slow. But I agree that avoiding unnecessary work is a good approach if it is slow. And that appears to be the case.
Reviewed-by: Simon Horman horms@kernel.org
Hello:
This patch was applied to netdev/net-next.git (main) by Jakub Kicinski kuba@kernel.org:
On Sat, 6 Sep 2025 14:45:35 -0700 you wrote:
The pmtu test takes nearly an hour when run on a debug kernel (10min on a normal kernel, so the debug slow down is quite significant). NIPA tries to ensure all results are delivered by a certain deadline so this prevents it from retrying the test in case of a flake.
Looks like one of the slowest operations in the test is calling out to ./openvswitch/ovs-dpctl.py to remove potential leftover OvS interfaces. Check whether the interfaces exist in the first place in sysfs, since it can be done directly in bash it is very fast.
[...]
Here is the summary with links: - [net-next] selftests: net: speed up pmtu.sh by avoiding unnecessary cleanup https://git.kernel.org/netdev/net-next/c/1c0353a6df82
You are awesome, thank you!
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