Re: [TEST] CX7 timeouts on reconfig w/ page pool failure injection

[Dragos Tatulea <dtatulea@nvidia.com>]

Hi,

On 13.08.26 00:41, Jakub Kicinski wrote:
> On Wed, 12 Aug 2026 21:48:31 +0200 Dragos Tatulea wrote:
>>> Ack, I'll send a patch to bump the timeout shortly.
>>>
>>> That said, the page pool warnings were probabilistic to begin with.
>>> And they were hit in page_pool_unref_netmem(), I think _some_ bug
>>> must still be there?
>>>
>>> IOW mlx5e_page_release_fragmented() is draining more references than
>>> the pp page use counter, that's not normal whether some command timeout
>>> out or not.  
>> Yes, this shouldn't happen.
>>
>> You mentioned tag net-next-hw-2026-07-03--00-00 as the first where the
>> crash occurred. Do you know if it ran before without crashing? I can't
>> find older data in nipa. And there's nothing that seems relevant around
>> that timeframe. I'm thinking that this issue could be older.
> 
> The data should be there but I think there may be limits on how much
> the DB returns. Anyway, querying directly - looks like until ~june
> there was something missing in the kconfig so the test was skipping.
> But here is a June 1st run which passes:
> 
> https://netdev.bots.linux.dev/logview.html?f=/logs/hwksft/CX7-dbg/results/672642/test-outputs/35-pp-alloc-fail-py/stdout
> 
> so either it was running and not crashing for all of june...
> or our crash tracking was broken in June :)
There were 2 corner cases that were missed by the last fix in
the area regarding handling of XDP buffer geometry changes
(fragments get deleted):
- napi_alloc_skb() error path. Probably this is the one one
  that triggered the crash, it occurs when injecting an error
  there.
- XDP drop path. Doesn't make sense but it is possible.

We have a fix in the pipeline for these.

Thanks,
Dragos