From owner-freebsd-stable Wed Feb 19 11:55:12 2003 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F33A837B401 for ; Wed, 19 Feb 2003 11:55:10 -0800 (PST) Received: from mail.sandvine.com (sandvine.com [199.243.201.138]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0EFEF43FA3 for ; Wed, 19 Feb 2003 11:55:08 -0800 (PST) (envelope-from don@sandvine.com) Received: by mail.sandvine.com with Internet Mail Service (5.5.2653.19) id ; Wed, 19 Feb 2003 14:55:06 -0500 Message-ID: From: Don Bowman To: Darren Henderson Cc: stable list Subject: RE: spontaneous reboot & gcc Date: Wed, 19 Feb 2003 14:55:06 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > From: Kris Kennaway [mailto:kris@obsecurity.org] > > On Tue, Feb 18, 2003 at 11:59:48PM -0500, Darren Henderson wrote: > > > > I'm seeing a spontaneous reboot in one very specific > circumstance that > > appears to be attributable to the use of gcc with -O2 optimization. > > Are you also compiling the kernel with -O2? If so, then "Don't do > that then". -O2 has had known serious bugs in the past. -O2 -pipe -malign-loops=4 -malign-jumps=4 -malign-functions=4 -mcpu=i686 -march=i686 -fno-gcse is what I'm using with good affect. I found one problem for sure with global common sub-expression elimination in the FreeBSD kernel w/ gcc 2.95. gcc 3.X is much more reliable, but not the default compiler for 4.X. The alignment used by default makes for fairly poor performance for pentium-4 / xeon architectures. --don To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message