Re: Linux: more cores = less concurrency.

2011/4/14 Florian Weimer <fweimer@bfk.de>:
> * Jesper Krogh:
>
>> If you have a 1 socket system, all of your data can be fetched from
>> "local" ram seen from you cpu, on a 2 socket, 50% of your accesses
>> will be "way slower", 4 socket even worse.
>
> There are non-NUMA multi-socket systems, so this doesn't apply in all
> cases.  (The E5320-based system is likely non-NUMA.)
>
> Speaking about NUMA, do you know if there are some non-invasive tools
> which can be used to monitor page migration and off-node memory
> accesses?

I am unsure it is exactly what you are looking for, but linux do
provide access to counters in:
/sys/devices/system/node/node*/numastat

I also find usefull to check meminfo per node instead of via /proc


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