In message <Pine.LNX.4.61.0506131337200.31861@m24s24.vlinux.de>, Hubert Feyrer 
writes:
>> On Mon, 13 Jun 2005, Martin Husemann wrote:
>>>>  * find someone who'll feel confident to commit the kernel code
>>> 
>>> IMHO all the kernel changes need  to be conditionalized on some kernel
>>> option. There are lots of vnd users out there, most of which never will use
>>> this format.
>
>Looking at the code, I wonder how to do this:
>  * just add an #ifdef for a symbol around the code, and keep the
>    data fields for compression handling in struct vnd_softc
>  * put the #ifdef also on the fields in struct vnd_softc
>  * use something else than an #ifdef/option (I have no idea on kernel
>    hacking :)
>

Unless the fields in vnd_softc are big, I'd include them 
unconditionally -- it simplifies life for anyone who wants to write a 
kernel data structure dumper.  (I'm thinking gdb rather than libkvm.)

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb