Where does this load come from?

Where does this load come from?

[Jurgen Kramer]

Hi,

I am seeing some strange load figures on my P4 Celeron based system
which I cannot explain. There always seem to be some load while there
are no real apps running. Stopping all daemons doesn't seem to effect
things at all.

Output from top with 2.6.4-rc1:

 13:16:38  up 38 min,  1 user,  load average: 1.67, 1.74, 1.57
62 processes: 59 sleeping, 3 running, 0 zombie, 0 stopped
CPU states:  47.5% user  52.4% system   0.0% nice   0.0% iowait   0.0%
idle
Mem:   515552k av,   93544k used,  422008k free,       0k shrd,   10980k
buff
        49632k active,              29284k inactive
Swap:  265064k av,       0k used,  265064k free                   59836k
cached

Is this a real problem or is top screwing things up here? 0.0% idle
doesn't seem right as for the load average. This system runs on RH9.

Compared to my P4 HT system running 2.6.4-rc1 on Fedore Core-1:

 13:17:42  up 30 min,  5 users,  load average: 0.12, 0.63, 0.64
91 processes: 90 sleeping, 1 running, 0 zombie, 0 stopped
CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
           total    1.2%    0.0%    0.4%   0.0%     0.0%    0.0%  198.0%
           cpu00    0.9%    0.0%    0.1%   0.0%     0.0%    0.0%   98.8%
           cpu01    0.1%    0.0%    0.3%   0.0%     0.0%    0.0%   99.4%
Mem:  1034456k av,  433712k used,  600744k free,       0k shrd,   26496k
buff
       239752k active,             152112k inactive
Swap:  787176k av,       0k used,  787176k free                  290452k
cached

This looks more like it.

What can be the problem here (if there is a real problem)?

Jurgen

Re: Where does this load come from?

[Denis Vlasenko]

On Saturday 28 February 2004 14:27, Jurgen Kramer wrote:
> Hi,
>
> I am seeing some strange load figures on my P4 Celeron based system
> which I cannot explain. There always seem to be some load while there
> are no real apps running. Stopping all daemons doesn't seem to effect
> things at all.
>
> Output from top with 2.6.4-rc1:
>
>  13:16:38  up 38 min,  1 user,  load average: 1.67, 1.74, 1.57
> 62 processes: 59 sleeping, 3 running, 0 zombie, 0 stopped
> CPU states:  47.5% user  52.4% system   0.0% nice   0.0% iowait   0.0%
> idle
> Mem:   515552k av,   93544k used,  422008k free,       0k shrd,   10980k
> buff
>         49632k active,              29284k inactive
> Swap:  265064k av,       0k used,  265064k free                   59836k
> cached

Post unabridged 'top b n 1' please.
Top version?
--
vda

Re: Where does this load come from?

[Christophe Saout]

Am Sa, den 28.02.2004 schrieb Jurgen Kramer um 13:27:

> I am seeing some strange load figures on my P4 Celeron based system
> which I cannot explain. There always seem to be some load while there
> are no real apps running. Stopping all daemons doesn't seem to effect
> things at all.

I've posted something like this before. It seems the load calculator
takes the io_wait "cpu usage" (which isn't really a cpu usage, it just
categorizes processes waiting in io_schedule here instead of the idle
time) into account. While doing heavy disk I/O my webserver showed a
load of over 40 but the cpu was idle. I don't like this either.

Re: Where does this load come from?

[Jurgen Kramer]

On Sat, 2004-02-28 at 14:04, Denis Vlasenko wrote: 
> On Saturday 28 February 2004 14:27, Jurgen Kramer wrote:
> > Hi,
> >
> > I am seeing some strange load figures on my P4 Celeron based system
> > which I cannot explain. There always seem to be some load while there
> > are no real apps running. Stopping all daemons doesn't seem to effect
> > things at all.
> >
> > Output from top with 2.6.4-rc1:
> >
> >  13:16:38  up 38 min,  1 user,  load average: 1.67, 1.74, 1.57
> > 62 processes: 59 sleeping, 3 running, 0 zombie, 0 stopped
> > CPU states:  47.5% user  52.4% system   0.0% nice   0.0% iowait   0.0%
> > idle
> > Mem:   515552k av,   93544k used,  422008k free,       0k shrd,   10980k
> > buff
> >         49632k active,              29284k inactive
> > Swap:  265064k av,       0k used,  265064k free                   59836k
> > cached
> 
> Post unabridged 'top b n 1' please.
> Top version?
> --
> vda

OK I found the culprit. Some script got started in rc.local which took
all the CPU time :-( (although it's a very simple script...).

Sorry that I bothered you with this...

Jurgen