help with the output of numactl (NUMA)

[Igor Veresov]

On Jul 19, 2012, at 2:45 PM, Stanley Guan wrote:

> Hi,
> 
> How to interpret the outputs of numactl?
> 
> $ numactl --hardware
> available: 1 nodes (0-0)
> node 0 size: 32284 MB
> node 0 free: 12941 MB
> node distances:
> node   0
>  0:  10
> 
> 
> $ numactl --show
> policy: default
> preferred node: current
> physcpubind: 0 1 2 3 4 5 6 7
> cpubind: 0
> nodebind: 0
> membind: 0
> 
> Specifically,
> 
> 1. What's the default policy?  Is it localalloc?
> 2. Our system has 8 cpu's and 1 node (?).
Yes, it seems to be only one node. So, the machine is not NUMA.
>  Is this one memory node?
What do you mean by that? This node obviously has memory, that what "node 0 size" indicates.
> 3. What does "10" mean in "0: 10"?
It's the relative cost of reaching node 0 from node 0.
Try that command on a real NUMA box, you're going to see an NxN matrix with access costs. 

igor

> 
> Thanks,
> 
> -Stanley