Re: Disabling COMPAT_FREEBSD4/5/6/7/9 in default kernel configurations

On 2024-05-11 07:38:38 (+0800), henrichhartzer@tuta.io wrote:
> Warner suggested that I run this by the list. In 2018, a bug report 
> was made for disabling COMPAT_FREEBSD4/5/6/7/9 (there's no 8). 6 years 
> later, I imagine this would be as good of a time as any to do this if 
> there's no obvious problems doing so.
>
> Here's the bug report: 
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=231768
>
> And a pull request in the spirit of the original patch: 
> https://github.com/freebsd/freebsd-src/pull/1228
>
> I imagine if this sounds like a good idea, it would land in 15.0. 
> Users could always recompile kernels with the old ABI functionality as 
> needed. I feel like we're all a little curious if anything still uses 
> this, and making this kind of change is probably the best way to find 
> out.

I think this is a terrible idea.  Removing things to find out what 
breaks is not the way we do things in FreeBSD.

Users who don't care about compatibility can build their own kernels.  
Many users do.  Our defaults however should be backwards compatible.

> Appreciate any feedback on this and hopefully we can reach some kind 
> of consensus on how to proceed in 2024.

One of the things users like about FreeBSD is our backwards 
compatibility.

What's wrong with being able to run old software without having to 
fight?

Philip