Date: Sat, 13 May 2006 03:01:18 -0400 From: Jonathan Noack <noackjr@alumni.rice.edu> To: Dmitry Pryanishnikov <dmitry@atlantis.dp.ua> Cc: freebsd-stable@FreeBSD.org, Kris Kennaway <kris@obsecurity.org> Subject: Re: RELENG_4 -> 5 -> 6: significant performance regression Message-ID: <4465843E.9070108@alumni.rice.edu> In-Reply-To: <20060513084236.W74146@atlantis.atlantis.dp.ua> References: <20060427160536.M96305@atlantis.atlantis.dp.ua> <20060427181226.GA66431@xor.obsecurity.org> <20060428122448.K57436@atlantis.atlantis.dp.ua> <20060428182818.GA10410@xor.obsecurity.org> <20060512161836.R75964@atlantis.atlantis.dp.ua> <20060513020051.GB18438@xor.obsecurity.org> <20060513084236.W74146@atlantis.atlantis.dp.ua>
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[-- Attachment #1 --] On 05/13/06 01:59, Dmitry Pryanishnikov wrote: > On Fri, 12 May 2006, Kris Kennaway wrote: >>>>>>> %Sys %Intr %Idl >>>>>>> RELENG_6 + rl0 45 40 15 >>>>>>> RELENG_6 + fxp0 45 35 20 >>>> >>>>> %Sys %Intr %Idl "time md5 -t" wall clock time >>>>> RELENG_6 + rl0 34 24 42 1:43 >>>>> RELENG_6 + fxp0 30 20 50 1:40 >>> >>> is caused by just these: >>> >>> options INVARIANTS >>> options INVARIANT_SUPPORT >> >> So what is the overall status? I am not clear what your results are. > > Results for RELENG_6+rl0 are > > %Sys %Intr %Idl > 34 24 42 > > without INVARIANTS, and > > %Sys %Intr %Idl > 45 40 15 > > with them. Other options like QUOTA and "makeoptions > CONF_CFLAGS=-fno-builtin" make almost no difference. So, under my test > conditions, the best % of idle CPU time under RELENG_6 is 42%, while > under RELENG_4 we had > > %Sys %Intr %Idl > 14 14 72 > > under the same conditions (and with INVARIANTS!) ;( > >>> available for application under RELENG_5/6 than under RELENG_4 (under >>> identical load pattern). I ran "time md5 -t" several (3-5 times) just to >>> confirm my assumptions, and results didn't vary more than 3%. So I >>> suppose >>> that ministat isn't necessary in my tests. >> >> Perhaps not when the difference is large, but you need to be very >> careful when differences are below ~10%, because it's easy to make >> incorrect conclusions. > > I agree with you. I would make more measurements if my aim was to > determine > which branch between RELENG_5 and _6 to use. But as these results are close > enough, and RELENG_6 is superiour regarding new features (and often > stability), IMHO there's no point in using RELENG_5 at all. I'm just trying > to understand why performance of RELENG_6 is worse than in RELENG_4 > _that much_, and whether this sad situation can be improved somehow. Have you tried putting I586_CPU in there? See http://lists.freebsd.org/pipermail/freebsd-stable/2005-December/020696.html. Also, use the link0 option with your fxp cards if they support it. See the fxp(4) man page for more info. Here is an example /etc/rc.conf entry: ifconfig_fxp0="inet xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx link0" -- Jonathan Noack | noackjr@alumni.rice.edu | OpenPGP: 0x991D8195 [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEZYRFUFz01pkdgZURArK7AKDAmfndjwh/aWzjTMOjyFKXJAfh0ACfSfD6 SUFJY7PEg2J12gKeWqnRick= =OyMc -----END PGP SIGNATURE-----
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