(Wrong) CPU utilization reported by top

[Ronald Klop]

On Sat, 23 Sep 2006 21:16:23 +0200, Václav Haisman <V.Haisman at sh.cvut.cz>  
wrote:

> Hi,
> I have noticed that top reports strange values for CPU utilization. The
> problem is that while it reports this for overall utilization...
>
> CPU states: 40.8% user,  0.0% nice,  3.7% system,  4.5% interrupt, 50.9%  
> idle
>
> ...it doesn't show a single process that would have over 1% of WCPU or  
> CPU!
>
>   PID USERNAME         THR PRI NICE   SIZE    RES STATE    TIME   WCPU  
> COMMAND
> 17980 xxxxx              1  96    0  5568K  3536K *Giant 213:05  0.00%  
> silc
> 88370 xxxxxxxxx          1  96    0  5584K  3592K RUN    211:07  0.00%  
> silc
> 93031 xxxxxx             5  20    0 58288K 40712K kserel 164:25  0.00%  
> vlc
> 20223 xxx                5  20    0   238M 29572K kserel  36:04  0.00%  
> java
> 17539 xxxxx              1  96    0 10692K  6032K select  26:51  0.00%  
> centericq
> 30491 xxxxxx             1  96    0  7076K  4708K select  26:48  0.00%
> ventrilo_srv
>
> I am quite positive it is the vlc process that eats most of the reported  
> 40%
> of CPU because if I turn it off the user time goes down bellow 10%. But
> despite that top shows zero in its row.
>
> The box is uniprocessor x86 FreeBSD 6.1.

I see the same and it is always with threaded applications (libpthread).
If you use libthr (see libmap.conf) it shows a lot better.

Ronald.

-- 
  Ronald Klop
  Amsterdam, The Netherlands