Why isn't ALTQ in GENERIC?

[Erik Osterholm]

On Wed, Jun 25, 2008 at 03:13:54AM +0200, Max Laier wrote:
> Hi Erik,
> 
> Am Di, 24.06.2008, 23:26, schrieb Erik Osterholm:
> > Can anyone tell me if there are good reasons for explicitly leaving
> > ALTQ out of the kernel?  More specific to my circumstances, if I'm
> > building kernels to be installed on every machine we deploy, is it
> > worth building a separate kernel for ALTQ for those few boxes which
> > will require it?
> >
> > Are there performance issues?  Stability issues?  Ultimately, I'm just
> > surprised that it's not available in GENERIC if there isn't a good
> > reason, but I can't find any documentation for that reason.
> 
> Short answer: Historical reasons.
> 
> Whole stroy: When ALTQ was added there were both performance and stability
> concerns.  For a long time we had a big #ifdef ALTQ in if_var.h to avoid
> one additional check for if_queue enqueue opperations.  These are now gone
> and I personally don't see any issues that would prevent ALTQ from being
> in GENERIC.  However, it's unclear which disceplines to turn on by
> default.  I'd like to see ALTQ in GERNERIC, but I've been reluctant to
> make the change on my own.  If we can get a quorum here, I'll reconsider
> it.
 

Thanks for the explanation.  I think that it would be nice to have in
GENERIC, but my immediate concerns were for with the performance and
stability.  

Thanks!

Erik