Date: Fri, 12 May 2006 22:00:51 -0400 From: Kris Kennaway <kris@obsecurity.org> 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: <20060513020051.GB18438@xor.obsecurity.org> In-Reply-To: <20060512161836.R75964@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>
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[-- Attachment #1 --] On Fri, May 12, 2006 at 11:25:58PM +0300, Dmitry Pryanishnikov wrote: > > Hello! > > On Fri, 28 Apr 2006, Kris Kennaway wrote: > >>>>makeoptions CONF_CFLAGS=-fno-builtin > >I don't know, it needs to be tested in your particular case. > > I've built another kernel, adding back > > makeoptions CONF_CFLAGS=-fno-builtin > options QUOTA > > Results are almost the same as w/o these 2 options. So the following > overhead difference: > > >>>> %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. > As my transfer takes much time (say 10 minutes) I've observed % of time > used many times during the transfer - they don't vary more than +/- several > (2-3) % during the main transfer phase (when transfer speed is stable). > My "time md5 -t" runs was used only as a confirmation that systat's numbers > are trustworthy - they simply confirm that there are _much_ less CPU cycles > 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. Kris [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEZT3TWry0BWjoQKURAgwqAJ0W2px8/9vpEUFd+urXk1umEgeH5wCg3a4h WgdyQvUc+HEHsEqgmrKm5c0= =94UA -----END PGP SIGNATURE-----home | help
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