[CentOS] Centos4 and Sun V40z x86_64

Thu May 25 01:06:04 UTC 2006
Peter Arremann <loony at loonybin.org>

On Wednesday 24 May 2006 19:52, Joshua Baker-LePain wrote:
> Now, now, you can't tease like that.  What do you mean by "proper numa
> settings", how do they correlate to BIOS settings, and how did you
> determine all that?

Sorry - I was in a hurry. 

Depending on your version you either have numa enabled by default or you just 
add a "numa=on" to your grub kernel parameters. If enabled or enabled depends 
on the version - i.e. if you have dual core cpus 4.1 disables numa by default 
and you need to enable it by hand. 

Can't remember anything in the bios about it though... check with numactl 
--hardware if you have numa support enabled. 

The rest mostly depends on the applications you're running. Numactl is a much 
underused utility. If you run just one process that takes up the majority of 
memory/cpu then numactl will be for you. If each cpu has enough memory for 
your processes, --localalloc can work very well - if you have a long running 
process with many threads, --interleave can show better performance. 

Bascially, once you have numa support enabled (if it is not already), try run 
your apps with numactl and different options and see which ones perform 
best :-)