[libvirt] [PATCH] virhostcpu: fix calculation of total CPU sockets

[Daniel P. Berrange]

On Fri, Nov 25, 2016 at 04:20:18PM +0800, Zhang Zhuoyu wrote:
> CPU sockets calculation is inconsistent with physical sockets when
> Host machine has more than one node. It only calculate the maximum
> socket number of all CPU nodes instead of summing up.
> 
> For example:
> 
> Architecture:          x86_64
> CPU op-mode(s):        32-bit, 64-bit
> Byte Order:            Little Endian
> CPU(s):                32
> On-line CPU(s) list:   0-31
> Thread(s) per core:    2
> Core(s) per socket:    8
> Socket(s):             2	<------ Host machine has 2 sockets
> NUMA node(s):          2
> Vendor ID:             GenuineIntel
> CPU family:            6
> Model:                 62
> Model name:            Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz
> Stepping:              4
> CPU MHz:               3074.296
> BogoMIPS:              5205.76
> Virtualization:        VT-x
> L1d cache:             32K
> L1i cache:             32K
> L2 cache:              256K
> L3 cache:              20480K
> NUMA node0 CPU(s):     0-7,16-23
> NUMA node1 CPU(s):     8-15,24-31
> 
> CPU model:           x86_64
> CPU(s):              32
> CPU frequency:       3021 MHz
> CPU socket(s):       1  	<----- Should be 2 sockets
> Core(s) per socket:  8
> Thread(s) per core:  2
> NUMA cell(s):        2
> Memory size:         131833636 KiB
> 
> "lscpu" shows host machine has 2 sockets, however "virsh nodeinfo"
> only calculate the maximum socket number of all CPU nodes,
> This patch fix it by summing sockets in all nodes up.

No, this is wrong interpretation of the data. 'virsh nodeinfo' is
actually reporting sockets *per* NUMA cell.

The nodeinfo data is in fact broken if you have a different
number of sockets in each cell. So we recommend that apps use
the capabilities XML as the accurate socket data.


Regards,
Daniel
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