Re: [dpdk-dev] [PATCH] net: introduce IPv4 ihl and version fields

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 6/14/2021 5:36 PM, Andrew Rybchenko wrote:
> On 6/10/21 12:22 PM, Olivier Matz wrote:
>> Hi Gregory,
>>
>> On Thu, Jun 10, 2021 at 04:10:25AM +0000, Gregory Etelson wrote:
>>> Hello,
>>>
>>> There was no activity that patch for a long time.
>>> The patch is marked as failed, but we verified failed tests and concluded
>>> that the failures can be ignored.
>>> https://patchwork.dpdk.org/project/dpdk/patch/20210527152858.13312-1-getelson@nvidia.com/
>>>
>>> How should I proceed with this case ?
>>> Please advise.
>>>
>>
>> I like the idea of this patch: to me it is more convenient to access to
>> these fields with a bitfield. I don't see a problem about using
>> bitfields here, glibc or FreeBSD netinet/ip.h are doing the same.
>>
>> However, as stated previously, this patch breaks the initialization API.
> 
> Very good point. I guess we overlooked it in a number of patches
> with fix RTE flow API items to start from corresponding network
> headers. We used unions there to avoid ABI breakage, but it looks
> like we have broken initialization API anyway.
> 

Hi Andrew,

What is broken with the flow API item updates, can you please give a sample?

> We should decide if initialization ABI breakage is a show-stopper
> for RTE flow API items switching to use network protocol headers.
> 
>> The DPDK ABI/API policy is described here:
>> http://doc.dpdk.org/guides/contributing/abi_policy.html#the-dpdk-abi-policy
>>
>>> From this document:
>>
>>    The API should only be changed for significant reasons, such as
>>    performance enhancements. API breakages due to changes such as
>>    reorganizing public structure fields for aesthetic or readability
>>    purposes should be avoided.
>>
>> So to follow the project policy, I think we should reject this path.
>>
>> Regards,
>> Olivier
>>
>