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Date:      Sat, 19 Mar 2005 18:59:02 -0500
From:      em1897@aol.com
To:        freebsd-questions@freebsd.org
Subject:   Re: FreeBSD 4.x Opteron Question
Message-ID:  <8C6FAF6C2C2F283-4FC-1280B@mblk-r24.sysops.aol.com>
In-Reply-To: <dc9ba04405031915053da7e282@mail.gmail.com>
References:  <20050318233039.33837.qmail@web90209.mail.scd.yahoo.com> <8C6FA2D0FF4CB85-BFC-1014C@mblk-r32.sysops.aol.com> <dc9ba04405031818452f544eeb@mail.gmail.com> <8C6FA491F181F0E-864-1095A@mblk-r42.sysops.aol.com> <dc9ba04405031915053da7e282@mail.gmail.com>

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You sound more like a politician than an engineer, Nick. I'm not a 
guinea pig,
and I have a business to run,and I'm not going to spend an extra $400. 
per
system to to get the same speed as with 4.x just to be one of the 
fellas.
I have no obligation to care about their plight, just as they've 
informed me
that they have no obligation to care about the needs of anyone in
their user base.

As for leadership, the FreeBSD developers told everyone that 5.3 was da 
bomb,
and that 5.4 would be better, but if you get Robert Watson in a 
choke-hold
he'll admit that its going to be the 6.x before they are where they 
should be
now. The truth is that the model they chose for 5.x just plain doesn't 
work.
If you get a charge out of playing follow the bozos, good for you. But 
I have
a car, and when the new model comes out I might test drive it, and if 
it sucks
I'll either keep my old car or buy something else. For now I'm slapping 
a coat of
wax on 4.x and hoping that someone figures it out shortly. I chose 
freeBSD
initially over linux not because there's a bunch of good guys on the 
project, but
because it was good. I'll stick with 4.x for the same reasons. 
Personally I think
its going to be a long, long time before FreeBSD is any good anymore. 
And
I don't have that kind of time. The entire point of the project is to 
improve
SMP performance, and several years in its worse than it was before. 
What
evidience is there that there is an end to this ridiculous tunnel?

-----Original Message-----

Hello,

On Fri, 18 Mar 2005 22:16:05 -0500, em1897@aol.com <em1897@aol.com> 
wrote:
>
>
> -----Original Message-----
> From: Nick Pavlica <linicks@gmail.com>
> To: em1897@aol.com <em1897@aol.com>
> Cc: freebsd-questions@freebsd.org
> Sent: Fri, 18 Mar 2005 19:45:44 -0700
> Subject: Re: FreeBSD 4.x Opteron Question
>
> :em1897,
> : I'm curious how you are testing. In my testing, the 5.4 pre IP
> :stack performed very well. I was able to get 100% more throughput
> :than Linux (2.6.10 FC3) under heavy load on the exact same hardware.
> :I was actually surprised at the difference because I have been a 
Linux
> :Zellot for years. I didn't see any packet loss in my tests, but I do
> :have good quality networking gear and servers. I was happy enough
> :after my testing that I'm going to move my 4.x servers to 5.4 when
> :it's released. I haven't tested dragonfly yet, but get all the
> :performance I need out of FreeBSD.
> :
> :--Nick
>
> on a side note, I thought top posting was a no-no? I see gmail has the
> same issues as AOL. Or are the issues with the old farts with their
> newsreaders? :-)
>
> I don't get your logic. You are converting your servers from 4.x to 
5.4
> because you've found that 5.4 is faster than linux? Is that some sort
> of riddle? FreeBSD has always been faster than linux; I'm comparing
> FreeBSD 4.x to 5.4, so I'm not sure what linux has to do with
> anything here.

I guess I was a little vague :). I brought up Linux because you
mentioned it in your earlier post, and wanted to share my results with
it. Additionally, I have used Linux in many projects over the years
and like to use it as a baseline of comparison. The point that I was
trying to make was that I was getting good results with 5.4 in my
tests. I have been pitting 4.x against 5.x since I began using
FreeBSD for my projects. The 4.x series does have an excellent
performance record that can't be questioned, however, 5.x gets the
job done for me.

>
> What you can "get" in terms of throughput doesn't always give you
> the right answer. My tests measure kernel performance; as I'm
> interested in routing/packet-processing performance. Sockets add
> a tricky variable. But I take the IP stack out of the equation
> altogether
> by bridging packets through a box, and I prefer to use a 50% load
> as timings sometimes change when you start to saturate things
> unnaturally. You won't be running your machine at 100% load, so
> it makes no sense to test it that way.
>
> For the latest test I have a 3.06Ghz xeon bridging 486,000pps.
> For FreeBSD 4.9, this is a 50% load. The load under 5.4 is 65%.
> It tests interrupt and process switching performance, which for
> a networking device is a key performance indicator. (I think)
> that the 5.4 kernel is threaded, so there are latencies that
> are very difficult to overcome. Linux has been threaded for
> a long time, and always has been a poor Uniprocessor
> performer. 5.4 is better than linux with one processor,
> but if you are UP then
> 4.x is clearly the way to go. Linux kills 5.4 with dual
> processors; in fact 5.4 seems to have higher network
> performance with 1 processor than 2. They still have
> a lot of issues to work out. DragonflyBSD has done a
> nice job with MP, but their performance is still a work
> in progress. For UP, their performance is dismal so
> its not quite where it needs to be, but its promising.
>

My tests are focused around simple network I/O and saturate all the
other subsystems before making the kernel break a sweat, MP or UP.
Curiously, all of my tests have never caused excessive CPU utilization
on 5.x, and do seem to consume more CPU resources on 4.x. I was
attributing this behavior to the scheduling and GIANT lock issues of
5.x . It's interesting to learn about your testing and that you are
capable of stressing the Kernel so easily. The tests I perform I
utilize my production and non production applications so that I could
measure what the net affect of OS performance would be in my
environment. I used to focus tests on more esoteric what if
scenarios, even trying to optimize my code before it was done, etc. I
have found over the years that performance is a tricky beast to catch.
Being a performance junkie like myself tends to make me focus on the
performance that I don't need rather than the performance that I do.
I still think about the 400HP Camero that I drove to get groceries,
and it still puts a smile on my face.

> I just wish that they had done a 64-bit version of
> 4.x. Because at the moment it seems that there is
> no way to utilize the opteron fully without having
> to use a slow version of the OS, which negates
> the gains. Its a real shame.

The bottom line in all of this is that 5.x and newer is where FreeBSD
is going and 4.x and older is now legacy software weather we like it
or not. In my mind this puts us in a postion to do one of the
following:
1) Focus our efforts on 4.11 that's being replaced anyway.
2) Stop using FreeBSD and use Linux, Solaris, OpenBSD, ......
3) Write our own OS that will solve all the worlds problems.
4) Accept the leadership and direction of the FreeBSD team and help
them make 5.x and newer the OS that we know that it can be.

Clearly option 4 is the best choice for FreeBSD and it's users for a
number of reasons. The developers need people to use the software
that they are working on so that they can improve it. In your case
you could help the developers identify the performance issues that you
are facing so that they can make improvements that would benefit you
and all the other users that need routing/packet-processing
performance. The dramatic changes made 5.x and newer can't be over
stated. Essentially they are writing a new OS the hard way. They
have to keep one foot behind while trying to move people forward with
very few resources. I'm truly amazed that they have made it this far.
Additionally, the core team chose to implement technologies that are
technically superior, but are very difficult to implement. Even with
the massive amount of resources that the Linux community has, they
have opted to hold off on these types of technologies for easier
solutions until they can implement them down the road. If we as a
community, get on board with the developers we will ultimately be able
to take advantage of these technologies, and will have a mature
solution when other projects are just starting to go down this
difficult journey.

I didn't really realize this myself until recently and wanted to share
my perspective. I know this has gotten of topic from the original
post and I apologize for that.

--Nick



>
>
> On Fri, 18 Mar 2005 18:55:14 -0500, em1897@aol.com <em1897@aol.com>
> wrote:
> >
> >
> > :Boris,
> > : I would agree that my initial impression of 5.3 was that it was
> slow
> > :compared to 4.x. After some tuning, I now have 5.3 running at an
> > :acceptable performance level. You may want to start testing the
> newer
> > :versions of 5 current. I have noticed improved performance on my
> test
> > :servers and believe that 5.4 will demonstrate an improvement in
> > :performance. I know that the guys on the performance list would 
like
> > :to get some good feedback if you find any specific bottlenecks with
> it
> > :as well.
> > :
> > :--Nick
> >
> > FYI, I recently testing bridging/network performance on 5.4-pre and
> its
> > about the same as 5.3: 25 to 30% more CPU load for the same traffic
> > levels than 4.x. SMP drops packets at about 60% load and seems to
> > have a lower capacity than UP. I'm sure some things are faster, but
> > networking is a large component for most people I think.
> > Threaded network stacks just don't seem to perform well,
> > certainly not on UP. Linux MP works much better, but
> > with 2 CPUs it has the capacity of FreeBSD 4.x with 1.
> > So its hard to justify.
> >
> > FWIW, its quite a bit better with UP than DragonFLY, but
> > dragonfly is much better with 2 processors.
> >
> > On Wed, 16 Mar 2005 14:51:43 -0800 (PST), Boris Spirialitious
> > <hardcodeharry@yahoo.com> wrote:
> > >
> > > --- cyb <cyb.@gmx.net> wrote:
> > > > http://www.freebsd.org/platforms/amd64.html
> > > >
> > > > Looks like you will need to use 5.3-release (or
> > > > 5.3-stable/5.4-prerelease if you have more than
> > > > 4GB).
> > > >
> > > > Why can you not use 5.3?
> > >
> > > 5.3 is too slow, and we have custom code. Why use
> > > faster hardware just to use slower version of O/S?
> > > Please don't start with flames. This is what I
> > > feel.
> > >
> > > I don't need so much RAM, so 4.x will work with
> > > 1 or 2GB of RAM?
> > >
> > > Boris
> > >
> > > >
> > > >
> > > > On Wed, 2005-03-16 at 09:43 -0800, Boris
> > > > Spirialitious wrote:
> > > > > --- Boris Spirialitious <hardcodeharry@yahoo.com>
> > > > > wrote:
> > > > > > When opteron support start for Freebsd? I have
> > > > 4.9.
> > > > > > is supported? Or 4.11 better? I can't use 5.x.
> > > > > >
> > > > > > Will a i386 disk boot on opteron system? Can I
> > > > > > use same disk image for intel and amd MBs? Any
> > > > > > big problems?
> > > > > >
> > > > > > Thanks,
> > > > > >
> > > > > > Boris
> > > > >
> > > > > Does anyone know answer please? Someone must use
> > > > > Opteron here
> > > > >
> > > > > Boris
> > > >
> > > > --
> > > > GnuPG key : 0xD25FCC81 |
> > > > http://cyb.websimplex.de/pubkey.asc
> > > > Fingerprint: D182 6F22 7EEC DD4C 0F6E 564C 691B
> > > > 0372 D25F CC81
> > > >
> > > >
> > > >
> > > >
> > >
> > > __________________________________
> > > Do you Yahoo!?
> > > Yahoo! Small Business - Try our new resources site!
> > > http://smallbusiness.yahoo.com/resources/
> > > _______________________________________________
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> > >
> >
> >
>
>


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