High CPU - where is my missing percentage???

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Jun 11th, 2009
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I have a quick question: my CPU is running as follows:

CPU utilization for five seconds: 79%/73%; one minute: 43%; five minutes: 27%

So why is it, when I add up the 5 sec % from all of the processes used, it equals 1.55%? What is using the other 77.45%, because frankly that seems like somewhat more important. Or is it that I am reading it wrong, and that they are not the same thing?

All the documentation that I've found so far relates to finding the process that's using the most CPU (seems sensible), and diagnosing from there. But my highest is 0.79% spanning-treee.

Many thanks!


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Joseph W. Doherty Thu, 06/11/2009 - 10:33
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The "missing" CPU is interrupt CPU. You won't see this under processes.

nate-miller Fri, 06/12/2009 - 19:16
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The first number is the total amount of CPU that's used, the second number is the amount of processor that's interrupt driven, and doesn't show up in the process list.

Search the site for troubleshooting high CPU due to interrupts.


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