[Beowulf] NUMA info request

Prentice Bisbal prentice at ias.edu
Mon Mar 24 09:04:40 PDT 2008

Eric Thibodeau wrote:
> Mark,
>    NUMA is an acronym meaning Non Uniform Memory Access. This is a
> hardware constraint and is not a "performance" switch you turn on. Under
> the Linux kernel there is an option that is meant to tell the kernel to
> be conscious about that hardware fact and attempt to help it optimize
> the way it maps the memory allocation to a task Vs the processor the
> given task will be using (processor affinity, check out taskset (in
> recent util-linux implementations, ie: 2.13+).
>    In your specific case, you would have 4Gigs per CPU and would want to
> make sure each task (assuming one per CPU) stays on the same CPU all the
> time and would want to make sure each task fits within the "local" 4Gig.
> Here is a link that should help you out with that respect:
> http://www.nic.uoregon.edu/tau-wiki/Guide:Opteron_NUMA_Analysis

For a more general (and detailed) discussion of NUMA,  you might be able
for find some computer architecture books at the library where you are a
grad student. Might be a little *too* much info, though.

This text book is a popular comp. architecture text book. you might even
say it's the "gold standard" I'm pretty sure it discusses NUMA somewhere
in between it's covers.


Prentice Bisbal
Linux Software Support Specialist/System Administrator
School of Natural Sciences
Institute for Advanced Study
Princeton, NJ

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