Re: [PATCH v3 7/7] selftests/tc-testing: Add netem test case exercising loops

[Jamal Hadi Salim]

On Mon, Mar 30, 2026 at 4:06 AM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
>
> Hi,
>
> On 3/26/26 7:01 PM, Stephen Hemminger wrote:
> > From: Victor Nogueira <victor@xxxxxxxxxxxx>
> >
> > Add a netem nested duplicate test case to validate that it won't
> > cause an infinite loop
> >
> > Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
> > Acked-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Victor Nogueira <victor@xxxxxxxxxxxx>
>
> Apparently the new test does not pass on NIPA:
>
> # not ok 364 8c17 - Test netem's recursive duplicate
> # Value doesn't match: bytes: 294 != 196
> # Matching against output: {'kind': 'netem', 'handle': '1:', 'root':
> True, 'refcnt': 2, 'options': {'limit': 1, 'duplicate': {'duplicate': 1,
> 'correlation': 0}, 'seed': 6495514880116664183, 'ecn': False, 'gap': 0},
> 'bytes': 196, 'packets': 2, 'drops': 1, 'overlimits': 0, 'requeues': 0,
> 'backlog': 0, 'qlen': 0}
>
> It's not clear to me if the causes is this series or the follow-up. I'm
> tentatively dropping the latter from PW; let's see how/if TDC is impacted.

We should hold on to Stephen's two patches until the skb bits one goes
in and settles.
Stephen's patches change the queue expectation which explains the
accounting mismatch. Stephen run the tdc tests and fix any changes in
the accounting...

cheers,
jamal