Re: CAP and performance problem

[Massimo Canonico <mex@di.unipmn.it>]

Hi dario,
> Sort of. However, since (you said) you have 4 cores, what I was thinking
> was more a situation where you have the 4 Dom0 vCPUs pinned to cores
> 0-2, and the VM vCPU pinned to core 3.
>
> You should be able to achieve that by doing right this:
>
> # xl vcpu-pin 0 all 0-2
> # xl vcpu-pin rubis-web all 3
I have set pin as you suggested:

[root@csitest ~]# xl vcpu-pin 0 all 0-2
[root@csitest ~]# xl vcpu-pin rubis-web all 3
[root@csitest ~]# xl vcpu-list
Name                                ID  VCPU   CPU State   Time(s) CPU 
Affinity
Domain-0                             0     0    0   -b-     384.5 0-2
Domain-0                             0     1    2   -b-     358.9 0-2
Domain-0                             0     2    2   -b-     224.6 0-2
Domain-0                             0     3    1   r--     257.0 0-2
rubis-web                            1     0    3   -b-    9251.6  3


> Does it make sense? Oh, and also, you have 4 _actual_cores_, right? Or
> is there any hyperthreading involved?
No hyperthreading are involved. At the end of this email I've pasted 
what /proc/cpuinfo says about cores (they are actual cores).

The experiment just finished said again that the service time is 3 times 
longer when CAP=50% with respect to the scenario with CAP=100%.

If you want me do more experiment, just let me know, I'll be happy to 
collaborate. I can also provide you my code: it's a very simple C++ code 
with a makefile that make you ready to run it in few seconds.

Cheers,
  Massimo

[root@csitest ~]# cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Xeon(R) CPU            5160  @ 3.00GHz
stepping        : 6
microcode       : 0xd2
cpu MHz         : 3000.186
cache size      : 4096 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae mce cx8 apic sep mca cmov pat 
clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good 
nopl pni monitor est ssse3 cx16 hypervisor lahf_lm dtherm
bogomips        : 6000.37
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            5160  @ 3.00GHz
stepping        : 6
microcode       : 0xd2
cpu MHz         : 3000.186
cache size      : 4096 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae mce cx8 apic sep mca cmov pat 
clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good 
nopl pni monitor est ssse3 cx16 hypervisor lahf_lm dtherm
bogomips        : 6000.37
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

processor       : 2
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Xeon(R) CPU            5160  @ 3.00GHz
stepping        : 6
microcode       : 0xd2
cpu MHz         : 3000.186
cache size      : 4096 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae mce cx8 apic sep mca cmov pat 
clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good 
nopl pni monitor est ssse3 cx16 hypervisor lahf_lm dtherm
bogomips        : 6000.37
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

processor       : 3
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Xeon(R) CPU            5160  @ 3.00GHz
stepping        : 6
microcode       : 0xd2
cpu MHz         : 3000.186
cache size      : 4096 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de tsc msr pae mce cx8 apic sep mca cmov pat 
clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good 
nopl pni monitor est ssse3 cx16 hypervisor lahf_lm dtherm
bogomips        : 6000.37
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management: