How is CPU usage calculated?

[Adam Vande More]

On Mon, Oct 18, 2010 at 1:54 PM, Martin Turgeon
<freebsd at optiksecurite.com>wrote:

> I didn't knew about -H to show individual threads, but my problem isn't
> there. My problem is that the summary printed in the first lines doesn't
> match the total of the process detailled under the summary. For example, I
> have a user CPU usage est 83.1% in the summary, but the only process worth
> mentionning in the list is mysqld that is taking 255.52% WCPU. That's far
> less than half the "CPU power" but 83% is far more. It's that difference
> that I don't understand.
>
> How is this possible?
>

man 1 top

83.1% doesn't mean what you think it does.


-- 
Adam Vande More