Re: modules problems

Matthias Urlichs (smurf@smurf.noris.de)
Sat, 21 Sep 1996 01:18:30 +0100


In linux.dev.kernel, article <9609202050.AA10757@bart-savagewood.MIT.EDU>,
warlord@mit.edu writes:
>
> Why not just make all the exported kernel interfaces the same whether
> the kernel is single processor or SMP?

The problem with this idea is that some inline procedures change when
you're using SMP. The preformance penalty for always doing the SMP thing on
a uniprocessor machine probably isn't acceptable to most people.

Data structures and kernel-callable procedures are covered by the symbol
version numbers.

> As someone who has to support a binary-only kernel module (AFS), this
> requirement really strains my resources.

You should do what Hannu did with his OSS sound driver suite -- write a
kernel abstraction layer, distribute the sources for it, and let the AFS
part only use functions and data structures exported by the abstractor.

This makes your driver a bit slower, but it doesn't slow down everything
else, which is a Good Thing (IMHO).

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