On Fri, Aug 04, 2023 at 05:23:32PM -0700, Martin KaFai Lau wrote: > On 8/3/23 10:07 PM, Geliang Tang wrote: > > Use rand() to generate a random netns name instead of using the fixed > > name "mptcp_ns" for every test. > > > > By doing that, we can re-launch the test even if there was an issue > > removing the previous netns or if by accident, a netns with this generic > > name already existed on the system. > > > > Note that using a different name each will also help adding more > > subtests in future commits. Hi Martin, I tried to run mptcp tests simultaneously, and got "Cannot create namespace file "/var/run/netns/mptcp_ns": File exists" errors sometimes. So I add this patch to fix it. It's easy to reproduce, just run this commands in multiple terminals: > for i in `seq 1 100`; do sudo ./test_progs -t mptcp; done > > I run test_progs repeatedly without rebooting qemu to save time. If there is > a test did not clean up its netns, I would rather uncover it earlier and fix > it instead. Randomizing the name is hiding the issue and does not help to > uncover the broken test sooner. Although this change is to mptcp test alone, > this could be referred in other future tests. I added "ip netns show" after "ip netns del" in v12 to check if there is a test did not clean up its netns. Thanks, -Geliang > > afaik, I don't remember bpf CI ever run into a test failure because the > picked name had already been used by the system. It seems you ran into this > issue a lot with the mptcp test in your setup. Could you explain a little > more?
