Date: Sat, 13 May 2006 08:59:01 +0300 (EEST) From: Dmitry Pryanishnikov <dmitry@atlantis.dp.ua> To: Kris Kennaway <kris@obsecurity.org> Cc: freebsd-stable@FreeBSD.org Subject: Re: RELENG_4 -> 5 -> 6: significant performance regression Message-ID: <20060513084236.W74146@atlantis.atlantis.dp.ua> In-Reply-To: <20060513020051.GB18438@xor.obsecurity.org> 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>
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Hello! 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. > Kris Sincerely, Dmitry -- Atlantis ISP, System Administrator e-mail: dmitry@atlantis.dp.ua nic-hdl: LYNX-RIPE
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