Re: ethdev: hide internal structures

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Tue, Nov 16, 2021 at 08:07:49PM +0000, Ferruh Yigit wrote:
> On 11/16/2021 5:54 PM, Tyler Retzlaff wrote:
> >
> >i thought someone was responsible for reviewing abi/api related changes
> >on the board to understand the implications of changes like this?
> >
> 
> Sorry for the negative impact on your product, I can understand the
> frustration.
> 
> The 'rte_eth_devices[]' was marked as '@internal' in the header file
> since 2012 [1], so it is not new, but it was not marked programmatically,
> only as comment in the header file.
> Expectation was applications to not directly use it.

unfortunately there are a lot of these expectations in the project code,
rarely do consuming applications get written in the way we would expect
and this is a lesson that if it is not mechanically enforced it isn't
prevented.

> 
> 
> For long term ABI stability, this is a good step forward, although
> the impact was known, best time for these kind of change is the 21.11
> release, otherwise change needs to wait (at least) one more year.

agreed, we appreciate what will be accomplished with the change.

> 
> This change has been discussed and accepted in the technical board [2],
> and a deprecation notice has been sent to mail list [3] for notification.

the notes from [2] aren't that clear, but i think it is fair you point
out that if [3] were read carefully it was implied that it would impact
ethdev. anyway, it is moot now.

> 
> Agree the announce was a little late than we normally do (although
> only a month late than what defined in process), this is accepted by
> the board to not miss the ABI break window (.11 release).
> As you will recognize, not only ethdev, but a few more device abstraction
> layer libraries had similar changes in this release.

yes, i understand. perhaps in the future it may be possible to introduce
some kind of __deprecation notice during compilation earlier than the
removal and it may have been noticed sooner. perhaps a patch that did
this near the time of the original notification [2].

i've left the details of the functional gap in my other reply to the
thread, hopefully you have a suggestion.

thanks Ferruh, appreciate it.

> 
> 
> [1]
> f831c63cbe86 ("ethdev: minor changes")
> 
> [2]
> https://mails.dpdk.org/archives/dev/2021-July/214662.html
> 
> [3]
> https://patches.dpdk.org/project/dpdk/patch/20210826103500.2172550-1-ferruh.yigit@intel.com/