Re: MTRR patches ??

David Wragg (dpw@doc.ic.ac.uk)
Wed, 28 Jan 1998 14:36:33 GMT


> My main concern is two-fold:
> [...]
> - does it really make sense to make a device out of it? Might it not be
> equally useful as just a "mtrr" user program that just happens to
> invoce a kernel module (that unloads immediately after having done its
> foul deed).

It could be as useful, and it might save a teeny bit of memory, but
isn't the use of module options to pass information into the kernel
ugly? It's fine for hardware parameters that are guaranteed not to
change, but unpleasant for actual communication.

For example, with Richard's patch you can easily find out the state of
the MTRRs with:

% cat /proc/mtrr

What simple way is there for a temporarily loaded module to do this,
except for using printks, which is a real hack. (Well, I suppose it
could add a proc entry!)

It would also not integrate well with kernel device drivers that could
take advantage of the MTRRs (though I have no idea whether there are
any, except presumably KGI).

--
Dave Wragg