Date: Mon, 02 Feb 2009 12:16:10 -0800 From: Julian Elischer <julian@elischer.org> To: FreeBSD virtualization mailing list <freebsd-virtualization@freebsd.org>, FreeBSD Net <freebsd-net@freebsd.org> Subject: Re: Vimage globals vs structures measurements. Message-ID: <4987548A.7000609@elischer.org> In-Reply-To: <4984241B.5010103@elischer.org> References: <498414E5.7020904@elischer.org> <4984241B.5010103@elischer.org>
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Julian Elischer wrote: > Julian Elischer wrote: >> >> anyone who has commands and args for their favourite >> thing the'd like me to test... send it in.. >> >> >> so far using ttcp I have seem no measureable difference. >> >> but I have more tests to do of course.. >> >> for example throughput with small packets with ttcp (KB/Sec).... >> >> >> x VIMAGE_GLOBALS >> + NO_VIMAGE_GLOBALS >> +-----------------------------------------------------------------+ >> | + xx | >> | + xxx + | >> | + xxx x ++++ | >> | x + x + + xxxxxxx +++++ | >> |x + ++ xx xxx + ++++xxx x x x +++++ ***xxxxx ++++++++| >> | |_____________A______M______| | >> | |________________AM________________| | >> +-----------------------------------------------------------------+ >> N Min Max Median Avg Stddev >> x 40 48016.01 57361.32 56268.06 54915.582 2554.0133 >> + 40 48999.66 59646.59 56261.58 56086.798 3119.1782 >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > > as I said before mst of my tests have shown no real change but this one > has the most change I've seen.. it's 160 byte udp packets sent between > two identical machines (both using the same kernel each time). > > > x VIMAGE_GLOBALS > + NO_VIMAGE_GLOBALS > +-----------------------------------------------------------------+ > | + + ++ xx x x | > | + + ++ +x++x +xx x x | > | + + +++ + +*+**x+xxxx x | > | + +++ +++x*++*+**x*x*xx x x x | > | + +*+++++x**+*+**x*x*x*xx x x xx | > | ++++*++++****+*+**x*x****x xxxx xxx | > | + + xx + ++++*++*+****+***********x*xxxxx xxxx x| > |+ +*+++ xx++*+*+*+****+****************x***x*xxx*xx x xx x| > | |__________A__________| | > | |_________A________| | > +-----------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 150 10175.11 11292.11 10763.80 10760.77 200.92124 > + 150 10075.64 11019.12 10591.68 10580.059 172.29227 > Difference at 95.0% confidence > -180.711 +/- 42.3572 > -1.67935% +/- 0.393626% > (Student's t, pooled s = 187.155) > > this one showed a 1.7% slowdown > where the one above showed a half percent speedup > (but not considered significant). > > The first one shown above was TCP with 1500 byte packets on bge 1G > interfaces.. > > more test ideas appreciated... more tests.. this one with iperf... x NO_VIMAGE_GLOBALS + VIMAGE_GLOBALS +-----------------------------------------------------------------+ | + x x x | | + + x x x x | | + + + + x x x x | | + + + + x x x x | | + + + + + x x x x x | | + + + + * x x x x x x | | + + + + * x * x x x x | | + + + + + * * * x x x x | | + + + + + + * * * x x x x | | + + + + + + + * * * x x x x | | + + + + + + + * * * * x x x x x | | + + + + + + * * * * * * x x x x | | + + + + + + * * * * * * x x x x | | + + + + + + * * * * * * * * x * x x | |x + + + + * * * * * * * * * * * * x x x| | |________A_________| | | |________MA_________| | +-----------------------------------------------------------------+ N Min Max Median Avg Stddev x 120 418 441 435 435.025 3.4089908 + 120 423 438 429 429.51667 3.4664862 Difference at 95.0% confidence -5.50833 +/- 0.869898 -1.26621% +/- 0.199965% (Student's t, pooled s = 3.43786) bigger is better... In this case we see that NO_VIMAGE_GLOBALS is better. Over several iterations I have come to the conclusion that other factors are overwhelming this change and that the effect of clustering all the 'global' variables together into a single global structure is negligible. If I can get some confirmation of this by others then the next step would be to simply remove the VIMAGE_GLOBALS option and all the global variables it covers. At least that's what seems next to me.. see: http://wiki.freebsd.org/Image/Notes200808DevSummit > > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
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