kernel features MIB

[Kris Kennaway]

Karsten Behrmann wrote:
> On Fri, 28 Dec 2007 12:19:14 +0100, Kris Kennaway wrote:
>> John Baldwin wrote:
>>> One of the things we have at work is a kern.features sysctl MIB that contains 
>>> nodes to indicate if a named feature is present.  For example, on i386 we 
>>> have kern.features.pae and we auto enable -DPAE for kernel modules if the 
>>> currently running kernel is using PAE using that sysctl.
>>> [...]
>>> Any objections to the idea?
>> I have wanted something like this for a long time.  In ports land they 
>> often need to know this kind of thing, e.g. is compat4x support enabled 
>> in the kernel, etc.
> 
> Hmm. But will everyone be running a kernel and system that the stuff they
> build will later run on? (when upgrading, or when building
> kernel and tools to be installed via NFS and pals)
> 
> Mind, it could be a good heuristic for the common cases, and directly
> useful for some libraries, but I'm thinking that we may need some easily-
> accessible override knobs. I could be wrong, though.

It would just be used to display informational messages about the need 
to recompile the kernel, etc.

Kris