Date: Mon, 23 Feb 2004 10:46:07 -0600 From: D J Hawkey Jr <hawkeyd@visi.com> To: "M. Warner Losh" <imp@bsdimp.com> Cc: freebsd-questions@freebsd.org Subject: Re: Clarification needed on Handbook: Tracking for Multiple Machines Message-ID: <20040223164607.GA29519@sheol.localdomain> In-Reply-To: <20040223.091205.31502112.imp@bsdimp.com> References: <20040222150723.GA25548@sheol.localdomain> <20040222161211.GB35539@marvin.home.local> <20040222172039.GA25979@sheol.localdomain> <20040223.091205.31502112.imp@bsdimp.com>
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On Feb 23, at 09:12 AM, M. Warner Losh wrote:
>
> In message: <20040222172039.GA25979@sheol.localdomain>
> D J Hawkey Jr <hawkeyd@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
--
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\__________________ \ D. J. HAWKEY JR. / __________________/
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