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Marcus Hall

2009-Feb-02 15:47 UTC

[Xen-users] Xen 3.3.0 cpu cache problems

Dear Xen users,

I have a problem with "Xen 3.3.0". All domU (paravirt) only have
"32 KB"
of cache instead of "6144 KB" as listed in dom0. This is really 
noticeable under load since the system tends to be really slow.

I did not have this problem with "Xen 3.2.1".

I''m using the same domU configuration files for the new and the old 
installation.

Look at the field, cache size.

*"cat /proc/cpuinfo" under dom0.*

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 23
model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
stepping    : 10
cpu MHz        : 2493.748
cache size    : 6144 KB
physical id    : 0
siblings    : 1
core id        : 0
cpu cores    : 1
fpu        : yes
fpu_exception    : yes
cpuid level    : 13
wp        : yes
flags        : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush 
acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc pni est ssse3 
cx16 lahf_lm
bogomips    : 4989.52
clflush size    : 64
cache_alignment    : 64
address sizes    : 38 bits physical, 48 bits virtual
power management:
*
"cat /proc/cpuinfo" under domU.*

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 23
model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
stepping    : 10
cpu MHz        : 2493.748
cache size    : 32 KB
physical id    : 0
siblings    : 1
core id        : 0
cpu cores    : 1
fpu        : yes
fpu_exception    : yes
cpuid level    : 13
wp        : yes
flags        : fpu de tsc msr pae cx8 apic sep cmov pat clflush acpi mmx 
fxsr sse sse2 ss ht syscall nx lm constant_tsc pni ssse3 cx16 lahf_lm
bogomips    : 4992.45
clflush size    : 64
cache_alignment    : 64
address sizes    : 38 bits physical, 48 bits virtual
power management:

*domU config file:*

kernel = "/etc/xen/kernel/vmlinuz-2.6.21-xen-domU"
builder=''linux''
memory = 3072
name = "host1"
cpus = "0-2"
vcpus = 3
vif = [ ''mac=xx:xx:xx:xx:xx:xx, vifname=host1,
bridge=bridge22'' ]
disk = [
''phy:/dev/mapper/xen_virtual_volume-host1_root,sda1,w'',
        
''phy:/dev/mapper/xen_virtual_volume-host1_var,sda2,w'',
        
''phy:/dev/mapper/xen_virtual_volume-host1_swap,sda3,w'',
         ''phy:/dev/mapper/xen_virtual_volume-host1_srv,sda4,w''
]
root = "/dev/sda1 ro"
extra = "4"

*Versions:*

app-emulation/xen-3.3.0
app-emulation/xen-tools-3.3.0
sys-kernel/xen-sources-2.6.21

Best regards,
Marcus

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

Robert Dunkley

2009-Feb-02 16:00 UTC

head link

RE: [Xen-users] Xen 3.3.0 cpu cache problems

This is a known problem ,there is a CPUID fix floating around that you apply to
the VM config file. Alternatively upgrading to Xen 3.3.1 should fix the problem.
 
Rob

________________________________

From: xen-users-bounces@lists.xensource.com on behalf of Marcus Hall
Sent: Mon 02/02/2009 15:47
To: xen-users@lists.xensource.com.
Subject: [Xen-users] Xen 3.3.0 cpu cache problems



Dear Xen users,

I have a problem with "Xen 3.3.0". All domU (paravirt) only have
"32 KB"
of cache instead of "6144 KB" as listed in dom0. This is really
noticeable under load since the system tends to be really slow.

I did not have this problem with "Xen 3.2.1".

I''m using the same domU configuration files for the new and the old
installation.

Look at the field, cache size.

*"cat /proc/cpuinfo" under dom0.*

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 23
model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
stepping    : 10
cpu MHz        : 2493.748
cache size    : 6144 KB
physical id    : 0
siblings    : 1
core id        : 0
cpu cores    : 1
fpu        : yes
fpu_exception    : yes
cpuid level    : 13
wp        : yes
flags        : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush
acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc pni est ssse3
cx16 lahf_lm
bogomips    : 4989.52
clflush size    : 64
cache_alignment    : 64
address sizes    : 38 bits physical, 48 bits virtual
power management:
*
"cat /proc/cpuinfo" under domU.*

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 23
model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
stepping    : 10
cpu MHz        : 2493.748
cache size    : 32 KB
physical id    : 0
siblings    : 1
core id        : 0
cpu cores    : 1
fpu        : yes
fpu_exception    : yes
cpuid level    : 13
wp        : yes
flags        : fpu de tsc msr pae cx8 apic sep cmov pat clflush acpi mmx
fxsr sse sse2 ss ht syscall nx lm constant_tsc pni ssse3 cx16 lahf_lm
bogomips    : 4992.45
clflush size    : 64
cache_alignment    : 64
address sizes    : 38 bits physical, 48 bits virtual
power management:

*domU config file:*

kernel = "/etc/xen/kernel/vmlinuz-2.6.21-xen-domU"
builder=''linux''
memory = 3072
name = "host1"
cpus = "0-2"
vcpus = 3
vif = [ ''mac=xx:xx:xx:xx:xx:xx, vifname=host1,
bridge=bridge22'' ]
disk = [
''phy:/dev/mapper/xen_virtual_volume-host1_root,sda1,w'',
        
''phy:/dev/mapper/xen_virtual_volume-host1_var,sda2,w'',
        
''phy:/dev/mapper/xen_virtual_volume-host1_swap,sda3,w'',
         ''phy:/dev/mapper/xen_virtual_volume-host1_srv,sda4,w''
]
root = "/dev/sda1 ro"
extra = "4"

*Versions:*

app-emulation/xen-3.3.0
app-emulation/xen-tools-3.3.0
sys-kernel/xen-sources-2.6.21

Best regards,
Marcus

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



The SAQ Group

Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ
SAQ is the trading name of SEMTEC Limited. Registered in England & Wales
Company Number: 06481952

http://www.saqnet.co.uk AS29219

SAQ Group Delivers high quality, honestly priced communication and I.T. services
to UK Business.

Broadband : Domains : Email : Hosting : CoLo : Servers : Racks : Transit :
Backups : Managed Networks : Remote Support.

ISPA Member

Find us in http://www.thebestof.co.uk/petersfield



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

Pasi Kärkkäinen

2009-Feb-02 16:01 UTC

head link

Re: [Xen-users] Xen 3.3.0 cpu cache problems

On Mon, Feb 02, 2009 at 04:47:49PM +0100, Marcus Hall
wrote:> Dear Xen users,
> 
> I have a problem with "Xen 3.3.0". All domU (paravirt) only have
"32 KB"
> of cache instead of "6144 KB" as listed in dom0. This is really 
> noticeable under load since the system tends to be really slow.
> 
> I did not have this problem with "Xen 3.2.1".
> 
> I''m using the same domU configuration files for the new and the
old
> installation.
> 
> Look at the field, cache size.
>
I think this bug is fixed in Xen 3.3.1.

-- Pasi

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

Marcus Hall

2009-Feb-02 16:27 UTC

head link

Re: [Xen-users] Xen 3.3.0 cpu cache problems

Sounds interesting. I am using Gentoo and unfortunately Xen 3.3.1 is not 
in portage yet.

What is this CPUID fix you are talking about and where can I find it? I 
have spent some hours searching on this issue and I have not found any 
solution yet.

Best regards,
Marcus Hall

Robert Dunkley wrote:> This is a known problem ,there is a CPUID fix floating around that you 
> apply to the VM config file. Alternatively upgrading to Xen 3.3.1 
> should fix the problem.
>  
> Rob
>
> ------------------------------------------------------------------------
> *From:* xen-users-bounces@lists.xensource.com on behalf of Marcus Hall
> *Sent:* Mon 02/02/2009 15:47
> *To:* xen-users@lists.xensource.com.
> *Subject:* [Xen-users] Xen 3.3.0 cpu cache problems
>
> Dear Xen users,
>
> I have a problem with "Xen 3.3.0". All domU (paravirt) only have
"32 KB"
> of cache instead of "6144 KB" as listed in dom0. This is really
> noticeable under load since the system tends to be really slow.
>
> I did not have this problem with "Xen 3.2.1".
>
> I''m using the same domU configuration files for the new and the
old
> installation.
>
> Look at the field, cache size.
>
> *"cat /proc/cpuinfo" under dom0.*
>
> processor    : 0
> vendor_id    : GenuineIntel
> cpu family    : 6
> model        : 23
> model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
> stepping    : 10
> cpu MHz        : 2493.748
> cache size    : 6144 KB
> physical id    : 0
> siblings    : 1
> core id        : 0
> cpu cores    : 1
> fpu        : yes
> fpu_exception    : yes
> cpuid level    : 13
> wp        : yes
> flags        : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush
> acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc pni est ssse3
> cx16 lahf_lm
> bogomips    : 4989.52
> clflush size    : 64
> cache_alignment    : 64
> address sizes    : 38 bits physical, 48 bits virtual
> power management:
> *
> "cat /proc/cpuinfo" under domU.*
>
> processor    : 0
> vendor_id    : GenuineIntel
> cpu family    : 6
> model        : 23
> model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
> stepping    : 10
> cpu MHz        : 2493.748
> cache size    : 32 KB
> physical id    : 0
> siblings    : 1
> core id        : 0
> cpu cores    : 1
> fpu        : yes
> fpu_exception    : yes
> cpuid level    : 13
> wp        : yes
> flags        : fpu de tsc msr pae cx8 apic sep cmov pat clflush acpi mmx
> fxsr sse sse2 ss ht syscall nx lm constant_tsc pni ssse3 cx16 lahf_lm
> bogomips    : 4992.45
> clflush size    : 64
> cache_alignment    : 64
> address sizes    : 38 bits physical, 48 bits virtual
> power management:
>
> *domU config file:*
>
> kernel = "/etc/xen/kernel/vmlinuz-2.6.21-xen-domU"
> builder=''linux''
> memory = 3072
> name = "host1"
> cpus = "0-2"
> vcpus = 3
> vif = [ ''mac=xx:xx:xx:xx:xx:xx, vifname=host1,
bridge=bridge22'' ]
> disk = [
''phy:/dev/mapper/xen_virtual_volume-host1_root,sda1,w'',
>         
''phy:/dev/mapper/xen_virtual_volume-host1_var,sda2,w'',
>         
''phy:/dev/mapper/xen_virtual_volume-host1_swap,sda3,w'',
>         
''phy:/dev/mapper/xen_virtual_volume-host1_srv,sda4,w'' ]
> root = "/dev/sda1 ro"
> extra = "4"
>
> *Versions:*
>
> app-emulation/xen-3.3.0
> app-emulation/xen-tools-3.3.0
> sys-kernel/xen-sources-2.6.21
>
> Best regards,
> Marcus
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>
> **
>
> ** *The SAQ Group*
>
> *Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ*
> SAQ is the trading name of SEMTEC Limited. Registered in England &
Wales
> Company Number: 06481952
>
>  
>
> http://www.saqnet.co.uk <http://www.saqnet.co.uk/> AS29219
>
> SAQ Group Delivers high quality, honestly priced communication and 
> I.T. services to UK Business.
>
> Broadband : Domains : Email : Hosting : CoLo : Servers : Racks : 
> Transit : Backups : Managed Networks : Remote Support.
>
>  
>
>  SAQ Group
>
>  
>
> *ISPA Member*
>
>  
>
> Find us in http://www.thebestof.co.uk/petersfield
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users

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

Marcus Hall

2009-Feb-03 14:24 UTC

head link

Re: [Xen-users] Xen 3.3.0 cpu cache problems

Hi,

I have done some research on on the cpuid parameter. If i am not wrong 
this only affects hvm virtualization, and it didn''t work for me. So my 
conclusion on this issue is that Xen 3.3.0 is broke and there is not 
much that can be done unless updating to 3.3.1.

Best regards,
Marcus Hall

Robert Dunkley wrote:> Hi Marcus,
>  
> My AMD setup had the problem under 3.3.0 and adding this to the VM 
> config file fixed it:
> cpuid >
[''0x80000005:ecx=xxxxxxxxxxxxxxxxxxxxxxxxkkkkkkkk,edx=xxxxxxxxxxxxxxxxxx
> xxxxxxkkkkkkkk'']
> I dont know if this will work for Intel and do not understand the full 
> CPUID signature but its worth a try.
>  
> Rob
> ------------------------------------------------------------------------
> *From:* xen-users-bounces@lists.xensource.com on behalf of Marcus Hall
> *Sent:* Mon 02/02/2009 16:27
> *To:* xen-users@lists.xensource.com.
> *Subject:* Re: [Xen-users] Xen 3.3.0 cpu cache problems
>
> Sounds interesting. I am using Gentoo and unfortunately Xen 3.3.1 is not
> in portage yet.
>
> What is this CPUID fix you are talking about and where can I find it? I
> have spent some hours searching on this issue and I have not found any
> solution yet.
>
> Best regards,
> Marcus Hall
>
> Robert Dunkley wrote:
> > This is a known problem ,there is a CPUID fix floating around that you
> > apply to the VM config file. Alternatively upgrading to Xen 3.3.1
> > should fix the problem.
> > 
> > Rob
> >
> >
------------------------------------------------------------------------
> > *From:* xen-users-bounces@lists.xensource.com on behalf of Marcus Hall
> > *Sent:* Mon 02/02/2009 15:47
> > *To:* xen-users@lists.xensource.com.
> > *Subject:* [Xen-users] Xen 3.3.0 cpu cache problems
> >
> > Dear Xen users,
> >
> > I have a problem with "Xen 3.3.0". All domU (paravirt) only
have "32 KB"
> > of cache instead of "6144 KB" as listed in dom0. This is
really
> > noticeable under load since the system tends to be really slow.
> >
> > I did not have this problem with "Xen 3.2.1".
> >
> > I''m using the same domU configuration files for the new and
the old
> > installation.
> >
> > Look at the field, cache size.
> >
> > *"cat /proc/cpuinfo" under dom0.*
> >
> > processor    : 0
> > vendor_id    : GenuineIntel
> > cpu family    : 6
> > model        : 23
> > model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
> > stepping    : 10
> > cpu MHz        : 2493.748
> > cache size    : 6144 KB
> > physical id    : 0
> > siblings    : 1
> > core id        : 0
> > cpu cores    : 1
> > fpu        : yes
> > fpu_exception    : yes
> > cpuid level    : 13
> > wp        : yes
> > flags        : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush
> > acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc pni est ssse3
> > cx16 lahf_lm
> > bogomips    : 4989.52
> > clflush size    : 64
> > cache_alignment    : 64
> > address sizes    : 38 bits physical, 48 bits virtual
> > power management:
> > *
> > "cat /proc/cpuinfo" under domU.*
> >
> > processor    : 0
> > vendor_id    : GenuineIntel
> > cpu family    : 6
> > model        : 23
> > model name    : Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
> > stepping    : 10
> > cpu MHz        : 2493.748
> > cache size    : 32 KB
> > physical id    : 0
> > siblings    : 1
> > core id        : 0
> > cpu cores    : 1
> > fpu        : yes
> > fpu_exception    : yes
> > cpuid level    : 13
> > wp        : yes
> > flags        : fpu de tsc msr pae cx8 apic sep cmov pat clflush acpi
mmx
> > fxsr sse sse2 ss ht syscall nx lm constant_tsc pni ssse3 cx16 lahf_lm
> > bogomips    : 4992.45
> > clflush size    : 64
> > cache_alignment    : 64
> > address sizes    : 38 bits physical, 48 bits virtual
> > power management:
> >
> > *domU config file:*
> >
> > kernel = "/etc/xen/kernel/vmlinuz-2.6.21-xen-domU"
> > builder=''linux''
> > memory = 3072
> > name = "host1"
> > cpus = "0-2"
> > vcpus = 3
> > vif = [ ''mac=xx:xx:xx:xx:xx:xx, vifname=host1,
bridge=bridge22'' ]
> > disk = [
''phy:/dev/mapper/xen_virtual_volume-host1_root,sda1,w'',
> >         
''phy:/dev/mapper/xen_virtual_volume-host1_var,sda2,w'',
> >         
''phy:/dev/mapper/xen_virtual_volume-host1_swap,sda3,w'',
> >         
''phy:/dev/mapper/xen_virtual_volume-host1_srv,sda4,w'' ]
> > root = "/dev/sda1 ro"
> > extra = "4"
> >
> > *Versions:*
> >
> > app-emulation/xen-3.3.0
> > app-emulation/xen-tools-3.3.0
> > sys-kernel/xen-sources-2.6.21
> >
> > Best regards,
> > Marcus
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@lists.xensource.com
> > http://lists.xensource.com/xen-users
> >
> > **
> >
> > ** *The SAQ Group*
> >
> > *Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ*
> > SAQ is the trading name of SEMTEC Limited. Registered in England &
Wales
> > Company Number: 06481952
> >
> > 
> >
> > http://www.saqnet.co.uk <http://www.saqnet.co.uk/> AS29219
> >
> > SAQ Group Delivers high quality, honestly priced communication and
> > I.T. services to UK Business.
> >
> > Broadband : Domains : Email : Hosting : CoLo : Servers : Racks :
> > Transit : Backups : Managed Networks : Remote Support.
> >
> > 
> >
> >  SAQ Group
> >
> > 
> >
> > *ISPA Member*
> >
> > 
> >
> > Find us in http://www.thebestof.co.uk/petersfield
> >
> >
------------------------------------------------------------------------
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@lists.xensource.com
> > http://lists.xensource.com/xen-users
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>

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

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