Measuring CPU with Hyperthreading and Linux

Hello

Please personally CC my email address to any responses:
[email protected]

I am currently running a dual Pentium 4 Xeon 2.4 GHz system containing Red Hat Linux 6.2 with the 2.4.20 kernel. The Pentium 4 Xeons report 4 cpu's to /proc/cpuinfo because they are hyperthreaded.

My problem lies in trying to measure the CPU usage with such programs as top or gtop. Typically, I see CPU loads in excess of 100% when I run top with some of my signal processing applications, but not more than 200%. Is this value out of 100%, 200%, or 400%? How does this dual, HT system kernel report this info to the OS?

Any help would be appreciated. Thanks

Matt

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Matthew A. Miling
Graduate Student - Computer Engineering
Syracuse University

phone: (315) 456-1215
cell: (315) 380-9307
e-mail: [email protected]
[email protected]

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Run top, then press 1 to get a 'per cpu' usage line, rather than the default combined thing.

Obviously you'll need a threaded app to take advantage of the processors, and preferably a 2.5 kernel with Ingo's HT scheduler patch...

Andrew