Re: A generic kernel compatibilty code

Ben Hutchings
2009-11-23T13:26:29Z

On Fri, 2009-11-20 at 13:07 -0800, Luis R. Rodriguez wrote:
> On Fri, Nov 20, 2009 at 1:00 PM, Ben Hutchings
> <bhutchings@solarflare.com> wrote:
> > On Fri, 2009-11-20 at 12:45 -0800, Luis R. Rodriguez wrote:
> >> Everyone and their mother reinvents the wheel when it comes to
> >> backporting kernel modules. It a painful job and it seems to me an
> >> alternative is possible. If we can write generic compatibilty code for
> >> a new routine introduced on the next kernel how about just merging it
> >> to the kernel under some generic compat module. This would be
> >> completey ignored by everyone using the stable kernel but can be
> >> copied by anyone doing backport work.
> >>
> >> So I'm thinking something as simple as a generic compat/comat.ko with
> >> compat-2.6.32.[ch] files.
> >>
> >> We've already backported everything needed for wireless drivers under
> >> compat-wireless under this format down to even 2.6.25.
> > [...]
> >
> > If you think 2.6.25 is old then I don't think you understand the scale
> > of the problem.
> >
> > OEMs still expect us to support RHEL 4 (2.6.9) and SLES 9 (2.6.5) though
> > the latter will probably be dropped soon. Some other vendors apparently
> > still need to support even 2.4 kernels!
>
> Heh understood. Well shouldn't this help with that then? Sure I'd love
> to see the Enteprise Linux releases on 2.6.31 but that's not going to
> happen right? Shouldn't this help then?

You'd really have to ask the 'enterprise' vendors whether they'd be
interested in working on some sort of shared forward-compat library. If
the library is to include a module rather than being statically linked
into each module that needs it then there can only be one instance in
the system.

Ben.

--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.