On Sun, Sep 16, 2007 at 09:11:00PM +0200, Jan Hoevers wrote:
> The NTP pool doesn't generate much traffic, but it comes in bursts of 
> approximately an hour. Yesterday I was closely monitoring such a burst, 
> with a bandwith of 230 kbit/sec, quite stable for about 30 minutes. 
> Nothing extreme for a 4801, I would say.
> It surprised me that the Soekris was running > 50% CPU, the "top" 
> display revealed that it was almost entirely interrupt processing.

The system may not be as busy as it appears.  The system estimates
the %CPU spent in the system, in userland, and in interrupt handling
by periodically "sampling" the state of the system.  If the system is
switching from idle to system/user/interrupt and back very quickly,
but the samples coincide with the "busy" intervals, then you will get
an incorrect result.  Google for "Secretly Monopolizing the CPU Without
Superuser Privileges" for a more elaborate explanation.

Dave

-- 
David Young             OJC Technologies
[EMAIL PROTECTED]      Urbana, IL * (217) 278-3933 ext 24
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