Determine if a kernel is built with a specific option?

[Giorgos Keramidas]

On Mon, 12 Jan 2009 14:56:21 +0000, "Andrew Brampton" <brampton+freebsd-hackers at gmail.com> wrote:
> If you were going to do this, would you make it a configure flag... ie
> --enable-polling... That way it doesn't matter if the build box is
> different?

If both choices are available (i.e. no header files are missing, no
link-time libraries are unavailable, and so on), I'd probably make it a
runtime option:

  * A configure-time flag to set the 'default' and

  * A runtime option to explicitly specify the current preference when
    the program runs.

This seems a bit more flexible, and does not require an expensive ``go
back to your vendor, and ask for a special build-time option'' cycle to
test different setups when a field installation is done.