WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

RE: [Xen-devel] xm speed

To: "Ian Pratt" <Ian.Pratt@xxxxxxxxxxxx>
Subject: RE: [Xen-devel] xm speed
From: "James Harper" <JamesH@xxxxxxxxxxxxxxxx>
Date: Fri, 10 Sep 2004 23:23:03 +1000
Cc: <xen-devel@xxxxxxxxxxxxxxxxxxxxx>
Delivery-date: Sat, 11 Sep 2004 02:53:08 +0100
Envelope-to: steven.hand@xxxxxxxxxxxx
List-archive: <http://sourceforge.net/mailarchive/forum.php?forum=xen-devel>
List-help: <mailto:xen-devel-request@lists.sourceforge.net?subject=help>
List-id: List for Xen developers <xen-devel.lists.sourceforge.net>
List-post: <mailto:xen-devel@lists.sourceforge.net>
List-subscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=subscribe>
List-unsubscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=unsubscribe>
Sender: xen-devel-admin@xxxxxxxxxxxxxxxxxxxxx
Thread-index: AcSXNXHYha1j/rzURlGEqeBEk1dnsQAAr0Mg
Thread-topic: [Xen-devel] xm speed
To do a very simple test I created a little script that does 'time xm
list' 6 times. Here's the output:

Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    198.7
gaia2              1        0    0  -b---     59.8    9601

real    0m9.403s
user    0m1.030s
sys     0m0.080s
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    200.0
gaia2              1        0    0  -b---     59.8    9601

real    0m9.997s
user    0m0.980s
sys     0m0.130s
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    201.4
gaia2              1        0    0  -b---     59.8    9601

real    0m9.999s
user    0m0.990s
sys     0m0.140s
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    202.7
gaia2              1        0    0  -b---     59.8    9601

real    0m9.999s
user    0m1.040s
sys     0m0.090s
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    204.0
gaia2              1        0    0  -b---     59.8    9601

real    0m9.998s
user    0m0.990s
sys     0m0.120s
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    205.3
gaia2              1        0    0  -b---     59.8    9601

real    0m9.998s
user    0m1.040s
sys     0m0.100s

It's closer to 10 seconds as you can see. After I type 'xm list', it
takes about 5 seconds for the heading to appear, and then roughly 2
seconds per domain. Load under Domain-0 is almost 0.

Another Proliant 1600 I have that is running xen has 2x550Mhz CPU's and
runs much better... roughly 3 seconds from typing 'xm list' to getting
output, and all the output rolls past pretty quick (4 domains on that
one).

The domain gaia2 is actually destroyed in the output above, it just
doesn't know it. Testing iscsi and it went into a spin logging bulk
stuff to the console. I find killing a domain in that state doesn't work
properly and I have to reboot Dom0 to get xend functioning properly
again.

James
 
> -----Original Message-----
> From: Ian Pratt [mailto:Ian.Pratt@xxxxxxxxxxxx]
> Sent: Friday, 10 September 2004 22:55
> To: James Harper
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxxx; Ian.Pratt@xxxxxxxxxxxx
> Subject: Re: [Xen-devel] xm speed
> 
> > I'm waiting about 2 seconds from typing 'xm list' and for something
to
> > appear. Is this normal? The machine is fairly old, it's a Compaq
> > Proliant 1600 with a single CPU running at 350Mhz. It's hardware
RAID
> > but that is pretty slow too.
> 
> If you look at the output of 'xm list' does the CPU time consumed
> by dom0 go up by 2s every time?
> 
> Is dom0 competing for CPU0 with a bunch of other busy domains?
> 
> On our 2.4GHz Xeon machines, I've noticed that running 'xm list'
> causes the amount of CPU consumed by dom0 to go up by around
> 100ms, which is quite a staggering amount given what it's
> actually doing. Python isn't the most efficient of languages, and
> we are doing a HTTP RPC between xm and xend, but this level of
> resource usage has always rather surprised me.
> 
> I guess we could use one of the python profiling tools to find
> out where the overhead is. Since this is all 'control plane' we
> haven't made any effort to make it efficient and have
> concentrated on flexibility. It it starts becoming a bottleneck
> it may be necessary to selectively recode bits in C.
> 
> Ian
> 
> 



-------------------------------------------------------
This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170
Project Admins to receive an Apple iPod Mini FREE for your judgement on
who ports your project to Linux PPC the best. Sponsored by IBM.
Deadline: Sept. 13. Go here: http://sf.net/ppc_contest.php
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel

<Prev in Thread] Current Thread [Next in Thread>