On 09.11.21 11:23, Philippe Gerum wrote:
> 
> Jan Kiszka <jan.kis...@siemens.com> writes:
> 
>> On 08.11.21 18:57, Philippe Gerum wrote:
>>>
>>> Jan Kiszka <jan.kis...@siemens.com> writes:
>>>
>>>> Hi Philippe,
>>>>
>>>> this dovetail commit makes the pipeline go red, crashing the kernels
>>>> (e.g. [1][2]). I hope this is something we can quickly fix in dovetail,
>>>> maybe via a config option?
>>>>
>>>> Jan
>>>>
>>>> [1] https://source.denx.de/Xenomai/xenomai-images/-/jobs/348118#L966
>>>> [2] https://source.denx.de/Xenomai/xenomai-images/-/jobs/348121#L1429
>>>
>>> Cobalt needs some update to cope with this now. I'll send a fix either
>>> way (dovetail or xenomai) tomorrow morning.
>>
>> This should be fixed in dovetail - API breakage. We can update Xenomai
>> later, along with enabling this feature again.
>>
> 
> We now have a change in the Dovetail tree which handles the fact that
> some Dovetail-based core might lag behind a bit API-wise regarding the
> new prctl-based call form. Since this simplifies the handling for any
> companion core in that particular case, this seems legitimate to add
> it. Tested on kvm-x86, -aarch64, and i.MX6-sabre with both Cobalt and
> EVL cores. Both test suites run properly, so far so good.

I'm not against this change, but activating it is no Xenomai 3.2
material as it will break the ABI. In addition, 3.2 was just released
and works fine with v5.10.76-dovetail. The next dovetail release should
not change this needlessly.

Again, just make it a feature and let the user/core enable it. Then we
can fork out stable-3.2 and let master gain this feature. All good.

> 
> However, please note that kernel API stability is not guaranteed by
> Dovetail in general in the upstream tree. The reasons not to guarantee
> that are well known and documented. I'll do my very best not to break it
> mindlessly, I can make it easier to cope with such changes with config
> switches, but do not expect it to be stable over time. Any change which
> may introduce such breakage will be pushed to the mailing list first.
> 

It's fine to make changes to newer kernels, but please refrain from
applying them to stable trees that Xenomai officially supports. That
would only enforce the creation of a stable dovetail branch, just for
Xenomai 3.x...

Thanks,
Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

Reply via email to