Re: a question about the numa information on my machine

Hi, all,

   I just identified the problem.
   I use Intel VTune Amplifier for profiling and it asks me to disable
C-States to avoid system hanging.
   Today, I popped up the idea to try to enable it and checked the
numa information again.
   It is o.k.! So, C-States is critical for NUMA in Nehalem Architecture?
   I don't know if it is always the case or just the case on my model.

David

On Wed, Jun 22, 2011 at 2:13 PM, Chia-Hung Lin <[email protected]> wrote:
> Hi,
>
>   I don't know if this post is appropriately for this board. (If not,
> which forum should I post to?)
>
>    I am wondering if my machine is configured right.
>    My machine equipped with two Intel Xeon  E5640 CPUs (each has 4 cores).
>    The red hat version is Red Hat Enterprise 5.5 and linux kernel is
> 2.6.18-194.el5
>    My question is when I check /sys/devices/system/node, there is only
> one node0 directory.
>    The information displayed by "numactl --show" is
> policy: default
> preferred node: current
> physcpubind: 0 1 2 3 4 5 6 7
> cpubind: 0
> nodebind: 0
> membind: 0
>
>    Why there is only one node instead of two? Is there any thing wrong
> with my machine?
>    Also, I found a message in dmesg :
> No NUMA configuration found
> Faking a node at 0000000000000000-0000000318000000
>
>    What should be a NUMA configuration look like?
>    Another thing I think strange is the BIOS setting. Its default is SMP.
>    When I try to change it to NUMA, I can only see one CPU after re-booting.
>    Is it normal? (the machine model is Dell T5500)
>    It will be very helpful if you can give me some direction.
>
>    Thanks a lot.
>
> David Lin
>