Date: Mon, 29 Jul 2002 09:05:37 -0700 (PDT) From: John Polstra <jdp@polstra.com> To: stable@freebsd.org Cc: gnb@itga.com.au Subject: Re: Is use of -O2 still deprecated for buildworld in -stable? Message-ID: <200207291605.g6TG5bK4042448@vashon.polstra.com> In-Reply-To: <200207290447.OAA22147@lightning.itga.com.au> References: <200207290447.OAA22147@lightning.itga.com.au>
next in thread | previous in thread | raw e-mail | index | archive | help
In article <200207290447.OAA22147@lightning.itga.com.au>, Gregory Bond <gnb@itga.com.au> wrote: > > My understanding is that whether or not -O2 *should* produce exactly > > equivalent code to -O, there are recurrent reports of people having > > trouble doing a buildworld with -O2 in -stable or in 4.x release > > trains, where their problems go away when they revert back to -O. > > The TCP checksum code seems to be the most common culprit - compiling with -O2 > seems to create checksum routines that fail in certain corner cases, meaning > some hosts or some data patterns cause TCP sessions to freeze. > > [I've not seen it myself, but it has been reported here a couple of times.] I fixed the checksum code in both -current and -stable a few weeks ago. FWIW, a kernel I built with "-O2 -fomit-frame-pointer" for a network-intensive configuration worked fine. For my application (generating and servicing zillions of web requests using special netgraph nodes I made) these options increased performance by about 9% compared to the same kernel built with "-O". John -- John Polstra John D. Polstra & Co., Inc. Seattle, Washington USA "Disappointment is a good sign of basic intelligence." -- Chögyam Trungpa To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200207291605.g6TG5bK4042448>