forwarding/ipfw/pf evolution (in pps) on -current

Thu Apr 25 10:53:24 UTC 2013

nice work!

On 4/24/13, Olivier Cochard-Labbé <olivier at cochard.me> wrote:
> Hi all,
>
> here is the result of my simple-and-dummy bench script regarding
> forwarding/ipfw/pf performance evolution on -current on a single-core
> server with one flow only.
> It's the result of more than 810 bench tests (including reboot between
> each) done twice for validating my methodology.
>
> # Disclaimer #
>
> 1. It's not a "max performance" bench: The purpose is to graph the
> variation of the performance only.
> 2. I know that using a single-core server in 2013 is a stupid idea but
> it's all I've got on my lab :-(
>
> # Why all these benchs ? #
>
> I've found performance regression regarding packet forwarding/ipfw/pf
> speed on -current comparing to 9.1 on my old server.
> glebius@ ask me to do some bisection hunting on different -current
> revision for spotting the culprit commit.
> But as a lazy guy, in place of doing bisection, I've choose about 50
> svn revision and graph them all: It's a lot's more easy to script this
> than a bisection algorithm :-)

For the future:

use the FreeBSD's git repo, and then the git bisect command. ;)

https://www.kernel.org/pub/software/scm/git/docs/git-bisect.html

> And the result is interesting…
>
> # The results #
>
> The gnuplot diagram in png format with some confirmed specifics spots
> is available here:
> http://gugus69.free.fr/freebsd/benchs/current/current-pps.png
>
> A confirmed spot is a measurable change between revision N-1 and revision
> N.
>
> => Remember that I'm used a single-core before reading the result!
> The "regression" of the new SMP pf is not really a regression: The
> system is now usable during this high PPS bench and it was not the
> case before this improvement.
>
> ## gnuplot data ##
>
> Available here: http://gugus69.free.fr/freebsd/benchs/current/plot/
> It's the data and plot file used for generating the graph: You can use
> them for zooming on it.
>
> ## ministat data ##
>
> Available here: http://gugus69.free.fr/freebsd/benchs/current/ministat/
>
> You can use it for comparing result between 2 revision, like as example:
> ministat -s 242160.ipfw 242161.ipfw
>
> ## raw data ##
>
> Outpout of pkg-gen during all tests:
> http://gugus69.free.fr/freebsd/benchs/current/raw/
>
> ## nanobsd images #
>
> All binary mages used for these benchs are here:
> http://gugus69.free.fr/freebsd/benchs/current/nanobsd-images/
>
> There is only one "full" image to be used for the first installation,
> and all other are "upgrade" image.
> They use the serial port as default console too.
>
> # Methodology used #
>
> ## First step: building a small lab ##
>
> I've used 3 old unused servers and a good switch:
> - One server as netmap pkt-gen packet generator (1.38Mpps of minimum
> size packet);
> - One server as netmap pkt-gen receiver;
> - One server with 2 NIC in the middle as a router/firewall, serial
> connection, and nanobsd image on it (very easy to upgrade): IBM
> eServer xSeries 306m with one core (Intel Pentium4 3.00GHz,
> hyper-threading disabled) and a dual NIC 82546GB connected to the
> PCI-X Bus;
> - a Cisco Catalyst switch for connecting all (its own statistics can
> be used as a tie breaker if I've got a doubt regarding the result
> given by netmap pkt-gen).
>
> All servers have another NIC for the admin network (bench script send
> SSH commands and nanobsd image upgrade over this dedicated NIC).
>
> I've used netmap pkt-gen for generating smallest packet size from the
> generator to the receiver like that:
> pkt-gen -i em0 -t 0 -l 42 -d 1.1.1.1 -D 00:0e:0c:de:45:df -s 2.2.2.2 -w 10
> Results was collected on the pkt-gen receiver.
>
> ## Second step: building small nanobsd images ##
>
> Now we need lot's of small nanobsd images generated from the svn
> revision number selected for the bench: cf script [1].
> About 50 revisions were selected between 236884 to 249506: Candidate
> chosen by reading the svn commit log.
>
> ## Third step: auto-bench script ##
>
> This auto-bench script [2] do these tasks:
> 1. Upgrading the server to the release to be tested;
> 2.   Uploading configuration set to be tested (forwarding-only, ipfw
> or pf) & reboot;
> 3.     Start the bench test, collecting the result, and reboot: 5
> times for each configuration-set;
> 4    Loop to next configuration set;
> 5. Loop to next release.
>
> ## Last step: converting result for ministat and gnuplot ##
>
> I've used a last script for interpreting the output of pkt-gen
> receiver for ministat and gnuplot [3].
>
> Because I'm not sure if I've used the good method for preparing my
> data, here is how I've generated the ministat and gnuplot graph:
>
> For just one test, the output of pkt-gen in receive mode is lot's of
> lines like that:
> main [1085] 400198 pps
> main [1085] 400287 pps
> main [1085] 400240 pps
> main [1085] 400235 pps
> main [1085] 400245 pps
> ...
>
> I've calculated the median value [3] (thanks ministat) all these
> results: This give me only one number for the test.
> => I did the same for each of the 5 same bench tests (same
> configuration-set, just a reboot between them). And I've put these 5
> numbers in the file named SVN-REV.CONFIG-SET.
> => From these 5 numbers, I've calculated the "median" value again:
> This give me a unique performance number that I've used as gnuplot
> data file.
>
> ## Bisection ##
>
> From this first result, I've selected others svn revision to
> generated: The goal was to spot the exact commit that brings the
> change.
> But it was not feasible for all regression spotted, because of
> unbuildable source or non-bootable resulting nanobsd image.
>
> ## Final: a full re-run ##
>
> Once all my benchs done, I've wait few days and re-started all tests a
> second time: Before to publish my result, I would to check that all my
> results were reproducible.
>
> # Annexes #
>
> ## configuration sets ##
>
> ### common to all configuration ###
> Forwarding enabled
> Ethernet flow-control disabled (dev.em.0.fc=0 and/or
> dev.em.0.flow_control=0)
> NIC drivers tunned:
>   hw.em.rx_process_limit: 500
>   hw.em.txd: 4096
>   hw.em.rxd: 4096
> static ARP entry configured on all server and static MAC/Pport entry
> on the switch too (prevent the switch to age out the packet receiver's
> MAC address).
>
> ### forwarding ###
> nothing special
>
> ### ipfw ###
>
> /etc/ipfw.rules:
>   #!/bin/sh
>   fwcmd="/sbin/ipfw"
>   # Flush out the list before we begin.
>   ${fwcmd} -f flush
>   ${fwcmd} add 3000 allow ip from any to any
>
> ### pf ###
>
> /etc/pf.conf:
>   set skip on lo0
>   pass
>
> [1]
> http://sourceforge.net/p/bsdrp/code/HEAD/tree/trunk/BSDRP/tools/bisection-gen.sh
> [2]
> http://sourceforge.net/p/bsdrp/code/HEAD/tree/trunk/BSDRP/tools/bench-lab.sh
> [3]
> http://sourceforge.net/p/bsdrp/code/HEAD/tree/trunk/BSDRP/tools/bench-lab-ministat.sh
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