Re: kernel structures in 2.0.29->2.0.30

Mike Meissner (meissner@cygnus.com)
Fri, 25 Apr 97 13:19:41 EDT

| > at least on intel, we should try to maintain module compatability.
| > btw, do you know of any binary-only modules besides afs/linux and
|
| Keeping binary compatibility is not always possible anyway. A module
| that uses "struct sock" won't even survive a re-configuration of _the
| same kernel version_ that toggles CONF_IP_MULTICAST, see the ifdef in
| <net/sock.h>. (Which cost me half a day of debugging recently.)

Or defining SMP for that matter. For example, on this machine (dual pentium
pro), I wanted to have a non-SMP kernel in case I got into a situation where
the SMP totally loses. I finally ended up changing the version number of the
kernel to have a 'smp' tag for the smp kernel.

I think the whole /lib/modules/<version> has room for improvement. In general,
each time you reconfigure the kernel, the configuration tools should bump a
minor revision number, so that you can go back and forth between kernels.
Emacs for instance does this, since the dumped emacs has pointers to the data
file in it.

--
Michael Meissner, Cygnus Solutions (East Coast)
4th floor, 955 Massachusetts Avenue, Cambridge, MA 02139, USA
meissner@cygnus.com,	617-354-5416 (office),	617-354-7161 (fax)