* Re: Linux scalability?
@ 2001-05-21 14:25 Dan Kegel
0 siblings, 0 replies; 12+ messages in thread
From: Dan Kegel @ 2001-05-21 14:25 UTC (permalink / raw)
To: sean, linux-kernel
Sean Hunter wrote:
> On Sat, May 19, 2001 at 10:31:01AM +0200, Sasi Peter wrote:
> > On Fri, 18 May 2001, Sean Hunter wrote:
> >
> > > Why would you want to run a web server with 8 processors rather than four
> > > webservers with 2 each?
> >
> > As you might already know, after the interviews to Mingo I assumed, that a
> > major portion of the achievements was enabled by the 2.4 scalability
> > enhacements. That is why I wrote to LKML, to ask about the 2.4
> > scalability, if anybody out there could tell us about the linux kernel's
> > scalability possibily compared to W2k scalability...
>
> Yup. The problem is that you're trying to measure scalability in performance
> of an i/o-bound task by comparing a machine with greater i/o resource but less
> processing power with one with greater processing but poorer i/o. Surprisingly
> enough, the one with the best i/o wins. This isn't really a fair comparison
> between the two platforms.
The document tree (21 - 26 GB) is small enough to fit in RAM (32 GB),
so the speed of the disk is not likely to have a noticable impact.
(See http://boudicca.tux.org/hypermail/linux-kernel/2001week20/1276.html )
A lot of people during the Mindcraft discussion made the mistake
of calling the test unfair.
Regardless of whether the initial test was fair, it actually showed
interesting performance weaknesses in Linux, ones the kernel team
has successfully addressed.
> My point was that in the real world having this configuration for a webserver
> is unlikely to be sensible at all.
That's certainly true. On the other hand, worrying about how many
nanoseconds a system call takes isn't really an issue in the
real world, but kernel hackers love to optimize system call overhead
anyway. This is the same sort of intellectual challenge. Plus,
it impresses the beancounters, and they're the ones who buy the
systems and keep us all employed.
- Dan
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-19 8:31 ` Sasi Peter
@ 2001-05-21 10:42 ` Sean Hunter
0 siblings, 0 replies; 12+ messages in thread
From: Sean Hunter @ 2001-05-21 10:42 UTC (permalink / raw)
To: Sasi Peter; +Cc: linux-kernel
Yup. The problem is that you're trying to measure scalability in performance
of an i/o-bound task by comparing a machine with greater i/o resource but less
processing power with one with greater processing but poorer i/o. Surprisingly
enough, the one with the best i/o wins. This isn't really a fair comparison
between the two platforms.
If you put the same disk array on both machines and got the same results, then
you'd have a point.
My point was that in the real world having this configuration for a webserver
is unlikely to be sensible at all.
Sean
On Sat, May 19, 2001 at 10:31:01AM +0200, Sasi Peter wrote:
> On Fri, 18 May 2001, Sean Hunter wrote:
>
> > Why would you want to run a web server with 8 processors rather than four
> > webservers with 2 each?
>
> As you might already know, after the interviews to Mingo I assumed, that a
> major portion of the achievements was enabled by the 2.4 scalability
> enhacements. That is why I wrote to LKML, to ask about the 2.4
> scalability, if anybody out there could tell us about the linux kernel's
> scalability possibily compared to W2k scalability...
>
> --
> SaPE - Peter, Sasi - mailto:sape@sch.hu - http://sape.iq.rulez.org/
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 8:17 ` Sean Hunter
2001-05-18 21:18 ` Rodger Donaldson
@ 2001-05-19 8:31 ` Sasi Peter
2001-05-21 10:42 ` Sean Hunter
1 sibling, 1 reply; 12+ messages in thread
From: Sasi Peter @ 2001-05-19 8:31 UTC (permalink / raw)
To: Sean Hunter; +Cc: linux-kernel
On Fri, 18 May 2001, Sean Hunter wrote:
> Why would you want to run a web server with 8 processors rather than four
> webservers with 2 each?
As you might already know, after the interviews to Mingo I assumed, that a
major portion of the achievements was enabled by the 2.4 scalability
enhacements. That is why I wrote to LKML, to ask about the 2.4
scalability, if anybody out there could tell us about the linux kernel's
scalability possibily compared to W2k scalability...
--
SaPE - Peter, Sasi - mailto:sape@sch.hu - http://sape.iq.rulez.org/
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 8:12 ` reiser.angus
2001-05-18 8:30 ` reiser.angus
@ 2001-05-19 8:26 ` Sasi Peter
1 sibling, 0 replies; 12+ messages in thread
From: Sasi Peter @ 2001-05-19 8:26 UTC (permalink / raw)
To: reiser.angus; +Cc: linux-kernel
On 18 May 2001, reiser.angus wrote:
> not really the same box
> look at the disk subsystem
> 7 x 9GB 10KRPM Drives and 1 x 18GB 15KRPM (html+log & os) for Win2000
> 5 x 9GB 10KRPM Drives (html+log+os) for TUX 2.0
> this is sufficient for a such difference
Don't you think that all the really needed stuff could just fit in the
enormous ram of the boxes?
--
SaPE - Peter, Sasi - mailto:sape@sch.hu - http://sape.iq.rulez.org/
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 8:17 ` Sean Hunter
@ 2001-05-18 21:18 ` Rodger Donaldson
2001-05-19 8:31 ` Sasi Peter
1 sibling, 0 replies; 12+ messages in thread
From: Rodger Donaldson @ 2001-05-18 21:18 UTC (permalink / raw)
To: linux-kernel
On Fri, May 18, 2001 at 09:17:11AM +0100, Sean Hunter wrote:
[Discussion of SPECWeb results]
> Why would you want to run a web server with 8 processors rather than four
> webservers with 2 each?
Because you want to win benchmarketing exercises, not demonstrate that your
architecture has any value in the real world whatsoever. Because you know
that you can induce people with financial approval to make stupid and
irrational decisions based on irrelevant data.
--
Rodger Donaldson rodgerd@diaspora.gen.nz
Klingons do *not* make good programmers. They make good PFWs and abuse
staff, though. "You have dishonoured our Ascend! I should kill you
where you stand!" -- Malcolm Ray
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
@ 2001-05-18 18:07 Dan Kegel
0 siblings, 0 replies; 12+ messages in thread
From: Dan Kegel @ 2001-05-18 18:07 UTC (permalink / raw)
To: sape, linux-kernel
Sasi Peter <sape@iq.rulez.org> wrote:
> I am just writing an essay, an have mentioned TUX as a performance and
> scalability linearity recort holder with TUX, referencing the specweb99
> website summary page:
>
> http://www.spec.org/osg/web99/results/web99.html
>
> However, taking a closer look, it turns out, that the above statement
> holds true only for 1 and 2 processor machines. Scalability already
> suffers at 4 processors, and at 8 processors, TUX 2.0 (7500) gets beaten
> by IIS 5.0 (8001), and these were measured on the same kind of box!
>
> How come, TUX is soooo good at the lowend (1 and 2 CPUs), and scales this
> bad?
Let's look at the scores. (BTW, SPECweb99 gets harder
as the scores get better; the document tree required to achieve a score of
3222 is twice as large as that required to achieve a score of 1438.)
SPECweb99 result summary:
date #cpu #nics L2 cache/cpu RAM tree score sw model MHz
1/2001 1 1 256K 2G 5G 1438 tux2 Compq Proliant DL320 800
6/2000 1 1 256K 2G 4G 1270 tux1 Dell Poweredge 6400 667
6/2000 2 2 256K 4G 7G 2200 tux1 Dell Poweredge 4400 800
3/2001 2 4 256K 4G 10G 3222 tux2 Dell Poweredge 2500 1000
2/2001 1 3 2M 8G 9G 2700 tux2 IBM xSeries 370 900
2/2001 2 4 2M 16G 13G 3999 tux2 IBM xSeries 370 900
6/2000 4 4 2M 8G 14G 4200 tux1 Dell Poweredge 6400 700
7/2000 8 8 2M 32G 21G 6387 tux1 Dell Poweredge 8450 700
11/2000 8 8 2M 32G 24G 7500 tux2 Dell Poweredge 8450 700
12/2000 8 8 2M 32G 21G 6407 tux1 IBM Netfinity 8500R 700
3/2001 2 3 256K 4G 8G 2499 IIS5/SWC HP NetserverLP2000r 1000
4/2001 8 8 2M 32G 26G 8000 IIS5/SWC Dell Poweredge 8450 700
IIS5/SWC only has two results on record, at 2 and 8 CPUs. They're hard
to compare, because they have different cache and RAM sizes and CPU speeds,
but it's safe to say that it performs poorly at 2 CPUs (compared to the 3/2001
results from Dell) and scales nearly linearly to perform comparatively well at 8 CPUs.
Looking at the IBM 1 and 2 CPU results, twice the CPU only got 1.4 times
the performance. Not sure TUX is scaling especially well even at 2 CPU's.
(And you can't blame this on disk drives, please don't try.)
So I agree, Tux doesn't seem to scale as well to multiple CPUs as does IIS5/SWC.
About comparing the Tux and IIS/SWC results on the Dell 8 CPU box:
the Tux measurement is 5 months older than the IIS/SWC measurement.
It's interesting to speculate how tux2 would do if tested today;
It looks like tux2 is about 12% faster than tux1 on 8-CPU machines.
In other words, 5 months of further development on tux and the 2.4 kernel yielded
a 12% speedup. Since IIS was only 4% faster than TUX, If Tux were measured today,
it might have improved enough to beat IIS/SWC, who knows.
- Dan
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 8:30 ` Ronald Bultje
@ 2001-05-18 9:05 ` Ronald Bultje
0 siblings, 0 replies; 12+ messages in thread
From: Ronald Bultje @ 2001-05-18 9:05 UTC (permalink / raw)
To: reiser.angus; +Cc: linux-kernel
On 18 May 2001 10:30:40 +0200, reiser.angus wrote:
> TUX does not exist on 2.2 kernel
> They use a RedHat 7.0 with a 2.4 kernel patched by RedHat (with TUX,
> zerocopy, etc..)
I am pretty sure the C'T article mentioned that TUX did use a 2.2.x
kernel - so it does exist. How else could they make a 2.2.x-kernel based
TUX vs. 2.4-test-kernel based TUX comparison?
Too bad the website doesn't mention the kernel number.
--
Ronald
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 7:24 ` Linux scalability? Sasi Peter
2001-05-18 8:12 ` reiser.angus
2001-05-18 8:17 ` Sean Hunter
@ 2001-05-18 8:30 ` Ronald Bultje
2001-05-18 9:05 ` Ronald Bultje
2 siblings, 1 reply; 12+ messages in thread
From: Ronald Bultje @ 2001-05-18 8:30 UTC (permalink / raw)
To: reiser.angus; +Cc: linux-kernel
On 18 May 2001 10:12:34 +0200, reiser.angus wrote:
> > However, taking a closer look, it turns out, that the above statement
> > holds true only for 1 and 2 processor machines. Scalability already
> > suffers at 4 processors, and at 8 processors, TUX 2.0 (7500) gets beaten
> > by IIS 5.0 (8001), and these were measured on the same kind of box!
> not really the same box
> look at the disk subsystem
> 7 x 9GB 10KRPM Drives and 1 x 18GB 15KRPM (html+log & os) for Win2000
> 5 x 9GB 10KRPM Drives (html+log+os) for TUX 2.0
>
> this is sufficient for a such difference
I read an article about TUX in the dutch C'T a few months ago (nov/dec
2000, I think) - the real difference (according to the article) was the
2.2.x kernel used in TUX. Look at the stats of the website, they used
Redhat 7.0 as base, with kernel 2.2.16. In the C'T, they also used a
2.4-test kernel for TUX, and this one didn't have these "scalibility
problems". The problem seemed to be SMP problems with systems with more
than two cpus in the 2.2.x-based kernel series. 2.4.x kernels didn't
seem to have this problem.
And as far as I know, TUX with 2.4.x kernel was faster than win2k on all
SMP-combinations.
--
Ronald
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 8:12 ` reiser.angus
@ 2001-05-18 8:30 ` reiser.angus
2001-05-19 8:26 ` Sasi Peter
1 sibling, 0 replies; 12+ messages in thread
From: reiser.angus @ 2001-05-18 8:30 UTC (permalink / raw)
To: Ronald Bultje; +Cc: linux-kernel
> I read an article about TUX in the dutch C'T a few months ago (nov/dec
> 2000, I think) - the real difference (according to the article) was the
> 2.2.x kernel used in TUX. Look at the stats of the website, they used
> Redhat 7.0 as base, with kernel 2.2.16.
TUX does not exist on 2.2 kernel
They use a RedHat 7.0 with a 2.4 kernel patched by RedHat (with TUX,
zerocopy, etc..)
-David
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 7:24 ` Linux scalability? Sasi Peter
2001-05-18 8:12 ` reiser.angus
@ 2001-05-18 8:17 ` Sean Hunter
2001-05-18 21:18 ` Rodger Donaldson
2001-05-19 8:31 ` Sasi Peter
2001-05-18 8:30 ` Ronald Bultje
2 siblings, 2 replies; 12+ messages in thread
From: Sean Hunter @ 2001-05-18 8:17 UTC (permalink / raw)
To: Sasi Peter; +Cc: linux-kernel
Why would you want to run a web server with 8 processors rather than four
webservers with 2 each?
Sean
On Fri, May 18, 2001 at 09:24:48AM +0200, Sasi Peter wrote:
> Hi!
>
> I am just writing an essay, an have mentioned TUX as a performance and
> scalability linearity recort holder with TUX, referencing the specweb99
> website summary page:
>
> http://www.spec.org/osg/web99/results/web99.html
>
> However, taking a closer look, it turns out, that the above statement
> holds true only for 1 and 2 processor machines. Scalability already
> suffers at 4 processors, and at 8 processors, TUX 2.0 (7500) gets beaten
> by IIS 5.0 (8001), and these were measured on the same kind of box!
>
> How come, TUX is soooo good at the lowend (1 and 2 CPUs), and scales this
> bad?
>
> --
> SaPE - Peter, Sasi - mailto:sape@sch.hu - http://sape.iq.rulez.org/
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: Linux scalability?
2001-05-18 7:24 ` Linux scalability? Sasi Peter
@ 2001-05-18 8:12 ` reiser.angus
2001-05-18 8:30 ` reiser.angus
2001-05-19 8:26 ` Sasi Peter
2001-05-18 8:17 ` Sean Hunter
2001-05-18 8:30 ` Ronald Bultje
2 siblings, 2 replies; 12+ messages in thread
From: reiser.angus @ 2001-05-18 8:12 UTC (permalink / raw)
To: Sasi Peter; +Cc: linux-kernel
> However, taking a closer look, it turns out, that the above statement
> holds true only for 1 and 2 processor machines. Scalability already
> suffers at 4 processors, and at 8 processors, TUX 2.0 (7500) gets beaten
> by IIS 5.0 (8001), and these were measured on the same kind of box!
not really the same box
look at the disk subsystem
7 x 9GB 10KRPM Drives and 1 x 18GB 15KRPM (html+log & os) for Win2000
5 x 9GB 10KRPM Drives (html+log+os) for TUX 2.0
this is sufficient for a such difference
-David
^ permalink raw reply [flat|nested] 12+ messages in thread
* Linux scalability?
2001-05-18 6:14 Linux OS boilerplate H. Peter Anvin
@ 2001-05-18 7:24 ` Sasi Peter
2001-05-18 8:12 ` reiser.angus
` (2 more replies)
0 siblings, 3 replies; 12+ messages in thread
From: Sasi Peter @ 2001-05-18 7:24 UTC (permalink / raw)
To: linux-kernel
Hi!
I am just writing an essay, an have mentioned TUX as a performance and
scalability linearity recort holder with TUX, referencing the specweb99
website summary page:
http://www.spec.org/osg/web99/results/web99.html
However, taking a closer look, it turns out, that the above statement
holds true only for 1 and 2 processor machines. Scalability already
suffers at 4 processors, and at 8 processors, TUX 2.0 (7500) gets beaten
by IIS 5.0 (8001), and these were measured on the same kind of box!
How come, TUX is soooo good at the lowend (1 and 2 CPUs), and scales this
bad?
--
SaPE - Peter, Sasi - mailto:sape@sch.hu - http://sape.iq.rulez.org/
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2001-05-21 14:26 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2001-05-21 14:25 Linux scalability? Dan Kegel
-- strict thread matches above, loose matches on Subject: below --
2001-05-18 18:07 Dan Kegel
2001-05-18 6:14 Linux OS boilerplate H. Peter Anvin
2001-05-18 7:24 ` Linux scalability? Sasi Peter
2001-05-18 8:12 ` reiser.angus
2001-05-18 8:30 ` reiser.angus
2001-05-19 8:26 ` Sasi Peter
2001-05-18 8:17 ` Sean Hunter
2001-05-18 21:18 ` Rodger Donaldson
2001-05-19 8:31 ` Sasi Peter
2001-05-21 10:42 ` Sean Hunter
2001-05-18 8:30 ` Ronald Bultje
2001-05-18 9:05 ` Ronald Bultje
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