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christie kumiko goto

2008-Jan-08 14:03 UTC

[Xen-devel] Question about machine time delay in guest domains (Full virtualization)

Hello, everyone,

I''m struggling with machine time delay in guest domains
(full virtualization).

In order to evaluate cpu performance in full virtualization, I applied
"SPEC CPU2006" and found that machine time of guest domains
is severely delayed from actual time.
->Actual test time : test time measured in guest domains = 4:1
(e.g., Actual test time =40 min, test time measured in guest domain time
=10 min)

I think there is some relationship between the number of
domains and cores.
(please see the following results)

Does anyone experience a similar problem (time delay in Xen)?

------------------------------------------------------
<<Environment>>
-Host machine has 2 cores (core number 0-1)
-Guest OSs: Full virtualization

*test 1
4 domains share 2 core (each domain has 2 vcpu)
->result: actual test time : test time measured in guest domains = 4:1

*test 2
2 domains share 1 core and the other 2 domains share the other 1 core.
->result: actual test time : test time measured in guest domains = 2:1
------------------------------------------------------

Thanks for your great kindness.
I wish you all the best for 2008.

Many thanks,
:)

-Christi


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

You, Yongkang

2008-Jan-09 01:24 UTC

head link

RE: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

On Tuesday, January 08, 2008 10:03 PM christie kumiko goto wrote:
> ------------------------------------------------------
> <<Environment>>
> -Host machine has 2 cores (core number 0-1)
> -Guest OSs: Full virtualization
> 
> *test 1
> 4 domains share 2 core (each domain has 2 vcpu)
> ->result: actual test time : test time measured in guest domains = 4:1
> 
> *test 2
> 2 domains share 1 core and the other 2 domains share the other 1 core.
> ->result: actual test time : test time measured in guest domains = 2:1
> ------------------------------------------------------
Hi Christi,

Did you try if only creating 1 domains with 2 cpus?
What''s your platform and guest OS version? There are some new
configurations for guest timer, such as timer_mode=1/2/3 (default timer mode is
0). You can set it in the guest config file. For some new OS, we can use
timer_mode=1/2 to make the timer more acccurate. But I am not sure if they can
work in your testing.

Best Regards,
Yongkang You

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

christie kumiko goto

2008-Jan-09 12:32 UTC

head link

Re: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

Hi, Yongkang,

Thanks so much!!
> Did you try if only creating 1 domains with 2 cpus?
I did the following 2 patterns.
  1) 2 domains with 2 vcpus (each domain shares 2 physical cpus)
  2) 4 domains with 2 vcpus (each domain shares 2 physical cpus)
>What''s your platform and guest OS version?
Could you see the following info?

platform: x86_64
OS: RHEL5u1 2.6.18 (details are below)

--------------------
#uname -a
Linux DL360-dom0-RHEL5u1 2.6.18-53.el5xen #1 SMP Wed Oct 10 16:48:44 EDT
2007 x86_64 x86_64 x86_64 GNU/Linux

# xm info
host : DL360-dom0-RHEL5u1
release : 2.6.18-53.el5xen
version : #1 SMP Wed Oct 10 16:48:44 EDT 2007
machine : x86_64
nr_cpus : 2
nr_nodes : 1
sockets_per_node : 1
cores_per_socket : 2
threads_per_core : 1
cpu_mhz : 1866
hw_caps : bfebfbff:20000800:00000000:00000140:0004e3bd:00000000:00000001
total_memory : 16381
free_memory : 1
xen_major : 3
xen_minor : 1
xen_extra : .0-53.el5
xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p
hvm-3.0-x86_64
xen_pagesize : 4096
platform_params : virt_start=0xffff800000000000
xen_changeset : unavailable
cc_compiler : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
cc_compile_by : brewbuilder
cc_compile_domain : build.redhat.com
cc_compile_date : Wed Oct 10 16:30:57 EDT 2007
xend_config_format : 2

# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU E5320 @ 1.86GHz
stepping : 7
cpu MHz : 1866.730
cache size : 4096 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts
acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor
ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips : 4669.03
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU E5320 @ 1.86GHz
stepping : 7
cpu MHz : 1866.730
cache size : 4096 KB
physical id : 1
siblings : 1
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts
acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor
ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips : 4669.03
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

-------------------------

Thanks again,
I really appreciate your kind help!
;)

-Christi


2008/1/9, You, Yongkang <yongkang.you@intel.com>:>
> On Tuesday, January 08, 2008 10:03 PM christie kumiko goto wrote:
>
> > ------------------------------------------------------
> > <<Environment>>
> > -Host machine has 2 cores (core number 0-1)
> > -Guest OSs: Full virtualization
> >
> > *test 1
> > 4 domains share 2 core (each domain has 2 vcpu)
> > ->result: actual test time : test time measured in guest domains =
4:1
> >
> > *test 2
> > 2 domains share 1 core and the other 2 domains share the other 1 core.
> > ->result: actual test time : test time measured in guest domains =
2:1
> > ------------------------------------------------------
>
> Hi Christi,
>
> Did you try if only creating 1 domains with 2 cpus?
> What''s your platform and guest OS version? There are some new
> configurations for guest timer, such as timer_mode=1/2/3 (default timer
mode
> is 0). You can set it in the guest config file. For some new OS, we can use
> timer_mode=1/2 to make the timer more acccurate. But I am not sure if they
> can work in your testing.
>
> Best Regards,
> Yongkang You
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>

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

You, Yongkang

2008-Jan-09 16:26 UTC

head link

RE: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

Hi Christi,
 
I can reproduce the time delay by just one x86_64 rhel5u1 guest under
specjbb2005, although the delay is not so great like your data. I found it would
be slow 100 secs, after running specjbb2005 2000 secs. I also tried timer_mode=1
or 2. They all met time slow issue.
 
BTW, I only catch this issue on x86_64 RHEL5u1 guest. With more guests running,
the guest timer would be slower. But x86_32 RHEL5u1 guest doesn''t meet
this issue. And without workload, guest timer is acceptable.
 
Best Regards,
Yongkang You
 

________________________________

From: christie kumiko goto [mailto:christie0123@gmail.com] 
Sent: Wednesday, January 09, 2008 8:33 PM
To: You, Yongkang
Cc: xen-devel@lists.xensource.com
Subject: Re: [Xen-devel] Question about machine time delay in guest domains(Full
virtualization)


Hi, Yongkang,

Thanks so much!!
> Did you try if only creating 1 domains with 2 cpus?
I did the following 2 patterns.
  1) 2 domains with 2 vcpus (each domain shares 2 physical cpus)
  2) 4 domains with 2 vcpus (each domain shares 2 physical cpus) 
>What''s your platform and guest OS version?
Could you see the following info?

platform: x86_64
OS: RHEL5u1 2.6.18 (details are below)

--------------------
#uname -a
Linux DL360-dom0-RHEL5u1 2.6.18-53.el5xen #1 SMP Wed Oct 10 16:48:44 EDT 
2007 x86_64 x86_64 x86_64 GNU/Linux

# xm info
host : DL360-dom0-RHEL5u1
release : 2.6.18-53.el5xen
version : #1 SMP Wed Oct 10 16:48:44 EDT 2007
machine : x86_64 
nr_cpus : 2
nr_nodes : 1
sockets_per_node : 1
cores_per_socket : 2
threads_per_core : 1
cpu_mhz : 1866
hw_caps : bfebfbff:20000800:00000000:00000140:0004e3bd:00000000:00000001
total_memory : 16381 
free_memory : 1
xen_major : 3
xen_minor : 1
xen_extra : .0-53.el5
xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p 
hvm-3.0-x86_64
xen_pagesize : 4096
platform_params : virt_start=0xffff800000000000 
xen_changeset : unavailable
cc_compiler : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
cc_compile_by : brewbuilder
cc_compile_domain : build.redhat.com
cc_compile_date : Wed Oct 10 16:30:57 EDT 2007 
xend_config_format : 2

# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU E5320 @ 1.86GHz
stepping : 7
cpu MHz : 1866.730 
cache size : 4096 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts 
acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor 
ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips : 4669.03
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual 
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU E5320 @ 1.86GHz
stepping : 7
cpu MHz : 1866.730
cache size : 4096 KB
physical id : 1
siblings : 1
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts 
acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor 
ds_cpl vmx est tm2 cx16 xtpr lahf_lm
bogomips : 4669.03
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

-------------------------

Thanks again,
I really appreciate your kind help!
;)

-Christi



2008/1/9, You, Yongkang <yongkang.you@intel.com>: 

	On Tuesday, January 08, 2008 10:03 PM christie kumiko goto wrote:
	
	> ------------------------------------------------------ 
	> <<Environment>>
	> -Host machine has 2 cores (core number 0-1)
	> -Guest OSs: Full virtualization
	>
	> *test 1
	> 4 domains share 2 core (each domain has 2 vcpu)
	> ->result: actual test time : test time measured in guest domains = 4:1 
	>
	> *test 2
	> 2 domains share 1 core and the other 2 domains share the other 1 core.
	> ->result: actual test time : test time measured in guest domains = 2:1
	> ------------------------------------------------------ 
	
	Hi Christi,
	
	Did you try if only creating 1 domains with 2 cpus?
	What''s your platform and guest OS version? There are some new
configurations for guest timer, such as timer_mode=1/2/3 (default timer mode is
0). You can set it in the guest config file. For some new OS, we can use
timer_mode=1/2 to make the timer more acccurate. But I am not sure if they can
work in your testing.
	
	Best Regards,
	Yongkang You
	
	_______________________________________________
	Xen-devel mailing list
	Xen-devel@lists.xensource.com
	http://lists.xensource.com/xen-devel
	




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

Dan Magenheimer

2008-Jan-31 15:24 UTC

head link

RE: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

Hi Christie --

I don''t know if you ever solved your problem or have been following
time-related threads on xen-devel, but I suspect your problem stems from the
fact that the virtual HPET has accuracy problems that are very noticeable with
64-bit Linux domains.  This is regardless of what you set for timer_mode.

To avoid this problem, you will need to set clocksource=pit in the
/etc/grub.conf file of your hvm domain.  Hopefully there will be a better
solution for this in the future.

Thanks,
Dan
  -----Original Message-----
  From: xen-devel-bounces@lists.xensource.com
[mailto:xen-devel-bounces@lists.xensource.com]On Behalf Of christie kumiko goto
  Sent: Wednesday, January 09, 2008 5:33 AM
  To: You, Yongkang
  Cc: xen-devel@lists.xensource.com
  Subject: Re: [Xen-devel] Question about machine time delay in guest
domains(Full virtualization)


  Hi, Yongkang,

  Thanks so much!!

  > Did you try if only creating 1 domains with 2 cpus?

  I did the following 2 patterns.
    1) 2 domains with 2 vcpus (each domain shares 2 physical cpus)
    2) 4 domains with 2 vcpus (each domain shares 2 physical cpus) 

  >What''s your platform and guest OS version?

  Could you see the following info?

  platform: x86_64
  OS: RHEL5u1 2.6.18 (details are below)

  --------------------
  #uname -a
  Linux DL360-dom0-RHEL5u1 2.6.18-53.el5xen #1 SMP Wed Oct 10 16:48:44 EDT 
  2007 x86_64 x86_64 x86_64 GNU/Linux

  # xm info
  host : DL360-dom0-RHEL5u1
  release : 2.6.18-53.el5xen
  version : #1 SMP Wed Oct 10 16:48:44 EDT 2007
  machine : x86_64 
  nr_cpus : 2
  nr_nodes : 1
  sockets_per_node : 1
  cores_per_socket : 2
  threads_per_core : 1
  cpu_mhz : 1866
  hw_caps : bfebfbff:20000800:00000000:00000140:0004e3bd:00000000:00000001
  total_memory : 16381 
  free_memory : 1
  xen_major : 3
  xen_minor : 1
  xen_extra : .0-53.el5
  xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p 
  hvm-3.0-x86_64
  xen_pagesize : 4096
  platform_params : virt_start=0xffff800000000000 
  xen_changeset : unavailable
  cc_compiler : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14)
  cc_compile_by : brewbuilder
  cc_compile_domain : build.redhat.com
  cc_compile_date : Wed Oct 10 16:30:57 EDT 2007 
  xend_config_format : 2

  # cat /proc/cpuinfo
  processor : 0
  vendor_id : GenuineIntel
  cpu family : 6
  model : 15
  model name : Intel(R) Xeon(R) CPU E5320 @ 1.86GHz
  stepping : 7
  cpu MHz : 1866.730 
  cache size : 4096 KB
  physical id : 0
  siblings : 1
  core id : 0
  cpu cores : 1
  fpu : yes
  fpu_exception : yes
  cpuid level : 10
  wp : yes
  flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts 
  acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor 
  ds_cpl vmx est tm2 cx16 xtpr lahf_lm
  bogomips : 4669.03
  clflush size : 64
  cache_alignment : 64
  address sizes : 36 bits physical, 48 bits virtual 
  power management:

  processor : 1
  vendor_id : GenuineIntel
  cpu family : 6
  model : 15
  model name : Intel(R) Xeon(R) CPU E5320 @ 1.86GHz
  stepping : 7
  cpu MHz : 1866.730
  cache size : 4096 KB
  physical id : 1
  siblings : 1
  core id : 0
  cpu cores : 1
  fpu : yes
  fpu_exception : yes
  cpuid level : 10
  wp : yes
  flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts 
  acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor 
  ds_cpl vmx est tm2 cx16 xtpr lahf_lm
  bogomips : 4669.03
  clflush size : 64
  cache_alignment : 64
  address sizes : 36 bits physical, 48 bits virtual
  power management:

  -------------------------

  Thanks again,
  I really appreciate your kind help!
  ;)

  -Christi



  2008/1/9, You, Yongkang <yongkang.you@intel.com>: 
    On Tuesday, January 08, 2008 10:03 PM christie kumiko goto wrote:

    > ------------------------------------------------------ 
    > <<Environment>>
    > -Host machine has 2 cores (core number 0-1)
    > -Guest OSs: Full virtualization
    >
    > *test 1
    > 4 domains share 2 core (each domain has 2 vcpu)
    > ->result: actual test time : test time measured in guest domains =
4:1
    >
    > *test 2
    > 2 domains share 1 core and the other 2 domains share the other 1 core.
    > ->result: actual test time : test time measured in guest domains =
2:1
    > ------------------------------------------------------ 

    Hi Christi,

    Did you try if only creating 1 domains with 2 cpus?
    What''s your platform and guest OS version? There are some new
configurations for guest timer, such as timer_mode=1/2/3 (default timer mode is
0). You can set it in the guest config file. For some new OS, we can use
timer_mode=1/2 to make the timer more acccurate. But I am not sure if they can
work in your testing.

    Best Regards,
    Yongkang You

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




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

Xen devel - Jan 2008 - Question about machine time delay in guest domains (Full virtualization)

[Xen-devel] Question about machine time delay in guest domains (Full virtualization)

RE: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

Re: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

RE: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)

RE: [Xen-devel] Question about machine time delay in guest domains(Full virtualization)