On 25/01/2021 10:05, Dmitry Kozlyuk wrote:
> On Mon, 25 Jan 2021 09:25:51 +0000, Kinsella, Ray wrote:
>> On 23/01/2021 11:38, Thomas Monjalon wrote:
>>> 22/01/2021 23:24, Dmitry Kozlyuk:
>>>> On Fri, 22 Jan 2021 21:57:15 +0100, Thomas Monjalon wrote:
>>>>> 22/01/2021 21:31, Dmitry Kozlyuk:
>>>>>> On Wed, 20 Jan 2021 11:24:21 +0100, Thomas Monjalon wrote:
>>>>>>> 20/01/2021 08:23, Dmitry Kozlyuk:
>>>>>>>> On Wed, 20 Jan 2021 01:05:59 +0100, Thomas Monjalon wrote:
>>>>>>>>> This is now the right timeframe to introduce this change
>>>>>>>>> with the new Python module dependency.
>>>>>>>>> Unfortunately, the ABI check is returning an issue:
>>>>>>>>>
>>>>>>>>> 'const char mlx5_common_pci_pmd_info[62]' was changed
>>>>>>>>> to 'const char mlx5_common_pci_pmd_info[60]' at rte_common_mlx5.pmd.c
>>>>>>>>>
>>>>>>>>
>>>>>>>> Will investigate and fix ASAP.
>>>>>>
>>>>>> Now that I think of it: strings like this change every time new PCI IDs
>>>>>> are
>>>>>> added to a PMD, but AFAIK adding PCI IDs is not considered an ABI
>>>>>> breakage,
>>>>>> is it? One example is 28c9a7d7b48e ("net/mlx5: add ConnectX-6 Lx device
>>>>>> ID")
>>>>>> added 2020-07-08, i.e. clearly outside of ABI change window.
>>>>>
>>>>> You're right.
>>>>>
>>>>>> "xxx_pmd_info" changes are due to JSON formatting (new is more
>>>>>> canonical),
>>>>>> which can be worked around easily, if the above is wrong.
>>>>>
>>>>> If the new format is better, please keep it.
>>>>> What we need is an exception for the pmdinfo symbols
>>>>> in the file devtools/libabigail.abignore.
>>>>> You can probably use a regex for these symbols.
>>>>
>>>> This would allow real breakages to pass ABI check, abidiff doesn't analyze
>>>> variable content and it's not easy to compare. Maybe later a script can be
>>>> added that checks lines with RTE_DEVICE_IN in patches. There are at most
>>>> 32 of
>>>> 5494 relevant commits between 19.11 and 20.11, though.
>>>>
>>>> To verify there are no meaningful changes I ensured empty diff between
>>>> results of the following command for "main" and the branch:
>>>>
>>>> find build/drivers -name '*.so' -exec usertools/dpdk-pmdinfo.py
>>>
>>> For now we cannot do such check as part of the ABI checker.
>>> And we cannot merge this patch if the ABI check fails.
>>> I think the only solution is to allow any change in the pmdinfo variables.
>>>
>>
>> So my 2c on this is that this is an acceptable work-around for the v21 (DPDK
>> v20.11) ABI.
>> However we are going to end up carrying this rule in libabigail.ignore
>> indefinitely.
>>
>> Would it make sense to just fix the size of _pmd_info to some reasonably
>> large value -
>> say 128 bytes, to allow us to drop the rule in the DPDK 21.11 v22 release?
>
> I don't think so. This is a JSON *string to be parsed;* considering its size
> as part of application *binary* interface is wrong in the first place.
Right - then is belongs in INTERNAL, I would say.
> As for
> content, checking that no PCI IDs are removed is out of scope for libabigail
> anyway.
Lets be clear PCI IDs - are _nothing_ to do with ABI.
> Technically we could fix _pmd_info size, but this still allows
> breaking changes to pass the check with no benefit.
ABI changes or other, please explain?
