Re: 50% CPU user usage but top doesn't list any CPU unfriendly task

[Norbert van Nobelen <norbert-kernel@edusupport.nl>]

The load and the CPU useage are two separate things:
Load: Defined by a programmer on an estimate on which his program is running 
100% fulltime, thus consuming little or more CPU/IO.
The interesting program you mention is the VoIP application. Is this program 
multithreaded and is every thread using a little bit of CPU? Than it quickly 
adds up to the mentioned 40%. The load is than also easily reached.


On Monday 03 January 2005 22:46, jerome lacoste wrote:
> Hi,
>
> on a fairly old box used as a desktop (PII 300 Mhz with 196M RAM), I
> observe the following strange behavior which I believe comes from the
> kernel.
>
> There's a VoIP known 'P2P' closed source application running, an IP
> tables based firewall and a remote ssh session initiated. When using
> top, sorting by CPU usage, no program is using more than a couple of
> percent of CPU. On the other side, the total CPU user time is at
> around 40%, with a 1.5 load average. Memory looks OK. The machine is
> responsive as usual.
>
> So I wonder why the cpu user time is at 40% without any particular
> program showing as using CPU in the top listing. 'Problem' was
> reproducible with 2.4.x and now with 2.6.8.1.
>
> So it this a real problem or is there something that I don't
> understand in particular? Thanks for the insight.
>
> Jerome
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