Re: [PATCH bpf-next v11 2/5] selftests/bpf: Use random netns name for mptcp

Martin KaFai Lau
2023-08-05T00:23:48Z

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.

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.

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?