[CentOS-devel] https://blog.centos.org/2020/12/future-is-centos-stream/

Wed Dec 9 18:04:14 UTC 2020
Phil Perry <pperry at elrepo.org>

On 09/12/2020 17:40, Stef Walter wrote:
> On Wed, Dec 9, 2020 at 6:33 PM David Hrbáč <david-lists at hrbac.cz 
> <mailto:david-lists at hrbac.cz>> wrote:
>         I don't use CentOS Stream, I use RHEL. I use RHEL to develop
>         software
>         for RHEL and compatible OS clones, including CentOS. If Stream
>         retains
>         binary compatibility, and specifically kernel ABI compatibility,
>         then
>         the users of the software packages we develop can continue to
>         use them.
>         If not, they can't. Simple as that. So please don't push rolling
>         kernel
>         updates to Stream that break the kernel ABI.
> Indeed. If any such broken change (eg: that breaks kernel ABI) is pushed 
> to Stream, that is treated as a serious problem by the RHEL engineering 
> teams. We have the necessary process in place to QE test changes before 
> they arrive in CentOS Stream.
> I understand this fact alone is not a panacea for all the problems 
> people are highlighting. But it does seem to cover your use case. From a 
> regression, stability, ABI, and kernel ABI perspective, it is the goal 
> and focus of many of us in RHEL Engineering for CentOS Stream to be stable.
> Cheers,
> Stef

Hi Stef,

Thank you for your response. You do realise I'm not just talking about 
whitelisted kernel symbols, but the whole kernel ABI?

Whilst the RHEL kernel ABI whitelist is great in principle, in practice 
I am yet to find a kernel driver that uses only symbols on the 
whitelist. As I said previously, every single driver I maintain broke 
between RHEL8.2 and RHEL8.3 due to changes in the kernel ABI.