Why do some software not get load balanced even when there are multiple cores?

Posted by Nav on Super User See other posts from Super User or by Nav
Published on 2011-03-19T07:27:05Z Indexed on 2011/03/19 8:12 UTC
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redhat

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multi-core

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load-balancer

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blade

While VTune Analyzer was running on a blade server with 8 cores, I observed the cpu useage percentage using mpstat -P ALL 1.

mpstat showed me that VTune was taking up 100% of a single core, while all other cores were idle.

Why does that happen? Shouldn't the OS (RHEL Server 5.2) automatically distribute load across cores? The same happened when I tried running MATLAB (even after enabling multithreading support in the MATLAB settings).

p.s: I'm a developer. Not a sys admin. So felt it better to ask here rather than at serverfault.

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