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-users

[Xen-users] XP HVM performance

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-users] XP HVM performance
From: Matthieu Patou <mat+Informatique.xen@xxxxxxxxx>
Date: Thu, 25 Jun 2009 11:28:57 +0400
Delivery-date: Thu, 25 Jun 2009 00:29:43 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090223 Thunderbird/3.0b2
I recently reinstalled an XP over my xen 3.2.1 (my conf is at the end of the mail).

And it's working but I find it a bit (well a big bit ...) too slow and use a lot of CPU.

For instance just having a taskmanager running use between 10/15% of CPU as reported by taskmanager and xm top.

When I run iozone the CPU usage is almost 95% whereas on a real XP workstation it's only a few percents.

The server hosting this XP is a 4 core Xeon E5320 @ 1.86GHz and I have only dom0 with 2 VCPU and 1 VCPU in XP.

I know that running XP in XEN will bring a penalty but I wasn't expecting such penalty.

Do I miss something ?

I also use the latest GPL PV drivers and found with iozone that the throughput is 1/3 of the raw capacity of the disk (as measured in dom0). Does this number seems normal to you or once more am I missing something ?

Finally I also did some tests with more than one VCPU but if the whole system load reduced somehow (which is logical) the IO perf where even worse. Is it a good idea to use more than one VCPU in HVM ?




my conf:
import os, re, time
arch = os.uname()[4]
if re.search('64', arch):
    arch_libdir = 'lib64'
else:
    arch_libdir = 'lib'
kernel = "/usr/lib/xen-3.2-1/boot/hvmloader"
builder='hvm'
memory = 512
shadow_memory = 8
name = "ecvssvz01"
vif = [ 'bridge=br2' ]
disk = [ 'phy:/dev/vg00/xphvm,hda,w','phy:/dev/hdb,hdd:cdrom,r']
device_model = '/usr/' + arch_libdir + '/xen-3.2-1/bin/qemu-dm'
boot="d"
acpi = 1
apic = 1
sdl=0
vnc=1
usb=1
usbdevice='tablet'
rtc_timeoffset=-(time.altzone)
localtime=0
vncconsole=0
monitor=1
serial='pty'
vncviewer = 0
stdvga=0
vcpus = 1

Matthieu

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

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