From owner-freebsd-questions Mon Nov 27 15:42:35 2000 Delivered-To: freebsd-questions@freebsd.org Received: from culverk.student.umd.edu (culverk.student.umd.edu [129.2.211.24]) by hub.freebsd.org (Postfix) with ESMTP id 1210F37B479 for ; Mon, 27 Nov 2000 15:42:33 -0800 (PST) Received: from localhost (culverk@localhost) by culverk.student.umd.edu (8.11.1/8.9.3) with ESMTP id eARNgOq00417; Mon, 27 Nov 2000 18:42:25 -0500 (EST) (envelope-from culverk@culverk.student.umd.edu) Date: Mon, 27 Nov 2000 18:42:24 -0500 (EST) From: Kenneth Culver To: Alfred Perlstein Cc: freebsd-questions@FreeBSD.ORG Subject: Re: compiler optimizations In-Reply-To: <20001127135408.P8051@fw.wintelcom.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Alright, I knew how to do it but thanks :-) Anyway, I compiled with -Os -march=pentiumpro and my kernel started randomly panicing on heavy disk activity (once starting netscape, and once syncing disks) so I think I'll just stick with the defaults. ================================================================= | Kenneth Culver | FreeBSD: The best NT upgrade. | | Unix Systems Administrator | ICQ #: 24767726 | | and student at The | AIM: muythaibxr | | The University of Maryland, | Website: (Under Construction) | | College Park. | http://www.wam.umd.edu/~culverk/| ================================================================= On Mon, 27 Nov 2000, Alfred Perlstein wrote: > * Kenneth Culver [001127 13:47] wrote: > > I'm just curious about something. I noticed the other day that the entire > > linux kernel is compiled with options -O2 -m486. I was wondering if this > > really causes any performance increase and was also wondering if there is > > anywhere on the web that can show this. I am wondering because I was going > > to use these options with FreeBSD (or -march=pentiumpro or -mpentiumpro, > > and -Os instead of -O2). > > Yes, the optimization works, however because we still want to support > 386s and because of bad experiances with the gcc optimizer in the > past we don't really like to debug problems with kernels that have > high levels of optimization because sometimes it's gcc's fault (or > at least it could be in the past). > > If you want to compile the kernel and world like that edit /etc/make.conf > and add your options to CFLAGS: > > CFLAGS= -O -pipe > > -- > -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] > "I have the heart of a child; I keep it in a jar on my desk." > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message