Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 7 Oct 2004 23:36:52 -0700
From:      "Ted Mittelstaedt" <tedm@toybox.placo.com>
To:        "Kris Kennaway" <kris@obsecurity.org>, <TM4525@aol.com>
Cc:        drosih@rpi.edu
Subject:   RE: What version of FBSD does Yahoo run?
Message-ID:  <LOBBIFDAGNMAMLGJJCKNAEHEEPAA.tedm@toybox.placo.com>
In-Reply-To: <20041007223348.GA22413@xor.obsecurity.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Kris and all,

  Sorry for the top post but would you quit feeding the trolls?

Ted Mittelstaedt

PS:  TM, shut up and post some benchmarks proving your side of
the argument.  Not that we would believe them but you deserve to
have to spend some time forging them up.


> -----Original Message-----
> From: owner-freebsd-questions@freebsd.org
> [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of Kris Kennaway
> Sent: Thursday, October 07, 2004 3:34 PM
> To: TM4525@aol.com
> Cc: questions@freebsd.org; drosih@rpi.edu
> Subject: Re: What version of FBSD does Yahoo run?
> 
> 
> On Thu, Oct 07, 2004 at 05:35:18PM -0400, TM4525@aol.com wrote:
> > In a message dated 10/7/04 4:06:34 PM Eastern Daylight Time, 
> drosih@rpi.edu 
> > writes:
> > Here's one benchmark, showing UDP packet/second generation
> >      rate from userland on a dual xeon machine under various
> >      target loads:
> > 
> >      Desired Optimal 5.x-UP  5.x-SMP 4.x-UP  4.x-SMP
> >       50000   50000   50000   50000   50000   50000
> >       75000   75000   75001   75001   75001   75001
> >      100000  100000  100000  100000  100000  100000
> >      125000  125000  125000  125000  125000  125000
> >      150000  150000  150015  150014  150015  150015
> >      175000  175000  175008  175008  175008  169097
> >      200000  200000  200000  179621  181445  169451
> >      225000  225000  225022  179729  181367  169831
> >      250000  250000  242742  179979  181138  169212
> >      275000  275000  242102  180171  181134  169283
> >      300000  300000  242213  179157  181098  169355
> > 
> > That does show results for both single-processor (5.x-UP 4.x-UP)
> > and multi- processor (5.x-SMP, 4.x-SMP) benchmarks.  It may be
> > that he ignored the table as soon as he read "dual Xeon".
> > --------------------------------------------
> > I haven't seen this before.
> 
> Check your email..the above was copied from an email of mine in this
> thread from earlier today.
> 
> > If I did, I would immediately ask:
> > 
> > - What is the control  here? What does your "benchmark" test?
> 
> UDP packet generation rate from userland.
> 
> > - Is this on a gigabit link? What are the packet sizes? Was network
> > availability a factor in limiting the test results?
> 
> I didn't run that benchmark myself, so I'm not the best person to
> answer all of your questions, and I've asked the person who did to
> comment in more detail.
> 
> > - What does "target load" mean? Does it mean don't try to send
> > more than that? If so, what does it show if you reach it? If you 
> > don't measure the utilization that it takes to saturate your "target"
> > I don't see the point of having it.
> >
> > - It seems that the only thing you could learn from this test would 
> > be what is the maximum pps
> > you could achieve unidirectionally out of a system. Why is that
> > useful, since its hardly ever the requirement unless you're 
> > building a traffic generator?
> 
> You can see from the data that 5.x systems are capable of pushing out
> more packets from userland than 4.x systems are.  That's an aspect of
> kernel performance, and it's one that's relevant for a number of
> applications involving high data-rate transmission from userland.  If
> that's not what you're interested in, then you can go and run your own
> benchmarks and let us know what you find out.
> 
> > - a relatively slow machine (a 1.7Ghz celeron with a 32-bit/33mhz
> > fxp NIC running 4.9) pushes over 250Kpps, so why is your machine, 
> > with seemingly superior hardware, so slow?
> 
> Because traffic is being generated from userland, not from within the
> kernel.
> 
> > Assuming that your benchmark does test something, Your "results"
> > seem to show that a uniprocessor machine is substantially more
> > efficient than an SMP box.
> 
> For this workload, yes.
> 
> > It also seems that the gap has widened between UP and SMP
> > performance in 5.x. Wasn't one of the goals of 5.x to substantially
> > improve SMP performance?
> 
> Yes, and it's ongoing.  You don't see it on this workload, but there
> are other benchmarks (e.g. mysql select testing) that I don't have to
> hand at the moment, which show the smp benefits of 5.3 more clearly.
> 
> > This seems to show the opposite.
> 
> No, it shows a small increase on SMP and a large increase on UP.
> Anyway, weren't you demanding an email ago that I produce benchmarks
> on UP systems, because no-one really uses SMP?
> 
> Kris
> 



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?LOBBIFDAGNMAMLGJJCKNAEHEEPAA.tedm>