Clarification needed on Handbook: Tracking for Multiple Machines

[D J Hawkey Jr]

On Feb 23, at 09:12 AM, M. Warner Losh wrote:
> 
> In message: <20040222172039.GA25979 at sheol.localdomain>
>             D J Hawkey Jr <hawkeyd at visi.com> writes:
> : True or False: Setting CPUTYPE to the lowest target CPU ("p2") in
> : a build machine's make.conf will cripple the performance of target
> : machines with higher CPUs ("p3", "p4", "i586", "i686", etc.).
> 
> False.  It might have a minor impact on performance, but not a major
> one.  At least in my experience.  Minor here means < 10% for something
> like the world stone.  Cripple to me implies > 25%.

OK, thanks. Just to satisfy my anal-retentive side, would that ~10%
degradation be a higher level of performance on a PIII (or higher)
with no CPUTYPE specified at all, given the same *FLAGS?

> : If "True", for optimized code across all machines, the code should
> : just be built on each machine, right?
> 
> That would give slightly better performance.  However, it can be more
> pain than it is worth if the number of machine types is high.

Consuming considerably more time and disk space, a shell script to
alter make.conf and rename /usr/obj between the build for each machine
is doable, though pro'lly not worth it. The install at each each box
would just have to mount it's corresponding /usr/obj tree.

Thanks, Warner,
Dave

-- 
  ______________________                         ______________________
  \__________________   \    D. J. HAWKEY JR.   /   __________________/
     \________________/\     hawkeyd at visi.com    /\________________/
                      http://www.visi.com/~hawkeyd/