Date: Wed, 14 Mar 2007 20:19:49 -0700 (PDT) From: youshi10@u.washington.edu To: freebsd-questions@freebsd.org Subject: Re: Optimizationn questions? Message-ID: <Pine.LNX.4.43.0703142019490.6819@hymn03.u.washington.edu> In-Reply-To: <200703150321.18033.danny@ricin.com>
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On Thu, 15 Mar 2007, Danny Pansters wrote: > On Thursday 15 March 2007 02:16, Gary Kline wrote: >> Two quick one for kernel and/or compiler wizards: first, is >> a 400Mz processor considered a 586 (for my KERNELCONF file)? > > Think its 686 (but really, leaving 486 and 586 in isn't going to slow down > booting or anything!) I always say: Use GENERIC unless you have a good reason > not to. > >> Second, is it safe to do a buildworld with -O3? If there are > > No. It's not supported if things break. > >> stability concerns, I'll go with the default when I rebuild my >> 6.2 systems. > > The defaults should be fine. Also, like I said consider just using GENERIC and > load the odd kmod if needed. Generally it's less headache and equal > performance. > >> thanks in advance, >> >> gary > > Cheers, > > Dan As Dan and Gary said -O3 isn't supported, and in many cases that "level of optimization" gets filtered out while compiling sections of FreeBSD. Besides, I've compiled stuff with -O3 and various optimizations in Gentoo Linux before, and let me say that it caused a great deal of headaches... that's why I stick with -O2 now, because it's better to have something in executable shape and a bit slower (arguably because some optimizations slow things down) than it is to have something run fast and break all the time. Some food for thought :). -Garrett
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