[libvirt] virGetNodeinfo .cpus

[Daniel P. Berrange]

On Fri, Apr 17, 2009 at 03:43:49PM +0300, Zvi Dubitzky wrote:
> virNodeGetInfo()  returns .cpus as 2  but the  /proc/cpuinfo of the node 
> shows 2 processors with 2 cores each  ('cpu cores')  . Or maybe the 'core 
> id' is what
> counts in the /proc/cpuinfo  and that  one gets vaue 0  , 1 only  i.e 
> totally 2 
> 
> can you clarify  ?

What libvirt driver are you using ?  QEMU or Xen.  The answer can be quite
complicated. In essence, for Xen, the /proc/cpuinfo does *not* reflect your
actual physical CPU topology. So for Xen we get the real data from the
hypervisor directly. For QEMU, libvirt just parses /proc/cpuinfo.

Your cpuinfo output below, shows 1 physical CPU with 2 cores 

> 
> Here is the output of /proc/cpuinfo:
> 
> processor       : 0
> vendor_id       : AuthenticAMD
> cpu family      : 15
> model           : 65
> model name      : Dual-Core AMD Opteron(tm) Processor 2210 HE
> stepping        : 2
> cpu MHz         : 1800.034
> cache size      : 1024 KB
> physical id     : 0
> siblings        : 2
> core id         : 0
> cpu cores       : 2
> apicid          : 0
> initial apicid  : 0
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 1
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca 
> cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt 
> rdtscp lm 3dnowext 3dnow pni cx16 lahf_lm cmp_legacy svm extapic 
> cr8_legacy
> bogomips        : 3600.06
> clflush size    : 64
> power management: ts fid vid ttp tm stc
> 
> processor       : 1
> vendor_id       : AuthenticAMD
> cpu family      : 15
> model           : 65
> model name      : Dual-Core AMD Opteron(tm) Processor 2210 HE
> stepping        : 2
> cpu MHz         : 1800.034
> cache size      : 1024 KB
> physical id     : 0
> siblings        : 2
> core id         : 1
> cpu cores       : 2
> apicid          : 1
> initial apicid  : 1
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 1
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca 
> cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt 
> rdtscp lm 3dnowext 3dnow pni cx16 lahf_lm cmp_legacy svm extapic 
> cr8_legacy
> bogomips        : 3600.23
> clflush size    : 64
> power management: ts fid vid ttp tm stc


Daniel
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