Date: Sat, 23 Oct 2010 17:14:05 -0700 From: David Wolfskill <david@catwhisker.org> To: freebsd-performance@freebsd.org Subject: Re: Possible evidence of performance regression for 8.1-S (vs. 7.1) Message-ID: <20101024001405.GT52404@albert.catwhisker.org> In-Reply-To: <4CC22758.3040201@freebsd.org> References: <20101020174854.GZ21226@albert.catwhisker.org> <4CBF8032.8000609@freebsd.org> <20101022231730.GP52404@albert.catwhisker.org> <20101022234817.GQ52404@albert.catwhisker.org> <4CC22758.3040201@freebsd.org>
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--6axCafNXXMM8qu6Q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 22, 2010 at 05:07:52PM -0700, Julian Elischer wrote: > On 10/22/10 4:48 PM, David Wolfskill wrote: > >On Fri, Oct 22, 2010 at 04:17:30PM -0700, David Wolfskill wrote: > >>On Wed, Oct 20, 2010 at 04:50:10PM -0700, Julian Elischer wrote: > >>>... > >>>try the 7.x machine but running the 8.x kernel.. i.e. change nothing, > >>>but boot the new kernel. > >>I just started that test, to run over the weekend. > >>... > >Moot point: the build fails. > > > that shouldn't happen > maybe you need to set the uname vars so that the build THINKS it is on 7.x OK; poking through the source tree, I found quite a few references to uname -- and several to kern.osreldate. I tried setting UNAME_r to a value that gegins with "7.1-RELEASE", and the build ran, completing with a status code of 0. I'm not especially confident that the result of the build was equivalent -- some of my statistics-gathering was a bit warped by the experience, but appears to be salvagable. I've fired off a sequence of 5 iterations of the test build, with the UNAME_r set as above; we should have answers (to the question of the rusage data for 8.1-S kernel and 7.1-R+ userland) by Monday. Thanks! > ... > it's not unusual to have to do this when cross building with a=20 > different kernel. :-} OK; I confess that it hadn 't occurred to me that this would be useful, let alone expected to work. (Sure, I expect some basic stuff to function in that environment, but with more "moving parts," I get a tad nervous.) > Running an 8.x kernel with the 7.x userland is a crucial part of=20 > debugging this. > we really can't do much more until we have the results. We should have them, as above. > If the build fails. it's either becasue the build detects the kernel=20 > rev (which we want to > stop with this) or because of a bug in 8.1. It's supposed to be=20 > downwards compatible. Well, I know that there were some changes made to our build in order to get it to even work under 8.x at all; I suppose I can be thankful that those seem to be based on uname values, vs. kern.osreldate. :-} Peace, david --=20 David H. Wolfskill david@catwhisker.org Depriving a girl or boy of an opportunity for education is evil. See http://www.catwhisker.org/~david/publickey.gpg for my public key. --6axCafNXXMM8qu6Q Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (FreeBSD) iEYEARECAAYFAkzDekwACgkQmprOCmdXAD2b3ACggBdUAkz68/98S0PHVsraKJ5t t2IAoIJkKNbQBUSiZhTASusMIfMugA9o =aBfP -----END PGP SIGNATURE----- --6axCafNXXMM8qu6Q--
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