Interrupt using all the CPU

[nocturnal]

Hi

No powerd running and i've never heard of that daemon. It's a pretty 
basic noname machine acting as a small scale webserver and a non-public 
nameserver. I've asked aroung and nobody can remember how long it's been 
like this so it's very possible that it's been acting like this since we 
installed it but i highly doubt it because we've had problems with it in 
the past and usually when something happens you check top at least once. 
It doesn't have much traffic either, if you shutdown the webserver the 
traffic is almost none, mostly arp and DNS traffic.

CPU states:  0.0% user,  0.0% nice,  0.0% system,  100% interrupt,  0.0% 
idle
Mem: 130M Active, 355M Inact, 108M Wired, 22M Cache, 73M Buf, 5668K Free
Swap: 329M Total, 316K Used, 329M Free

This is what it usually looks like, or here in an iostat view, in case 
it helps.

       tty             ad4              ad6             ast0             cpu
  tin tout  KB/t tps  MB/s   KB/t tps  MB/s   KB/t tps  MB/s  us ni sy in id
    0    3 28.14   2  0.06   0.57   0  0.00   0.00   0  0.00   0  0  7 83 10
    0  227 16.00   1  0.02   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77 16.00  11  0.17   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  6.00   1  0.01   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 50 50
    0   76 16.00   2  0.03   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0
    0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0 
100  0




Med vänliga hälsningar

Stefan Midjich aka nocturnal
[Swehack] http://swehack.se


Daan Vreeken [PA4DAN] wrote:
> On Monday 03 July 2006 12:26, nocturnal wrote:
>> Hi
>>
>> The clock?
>>
>> interrupt                          total       rate
>> irq0: clk                       25130235         99
>> irq1: atkbd0                           4          0
>> irq6: fdc0                             1          0
>> irq7: ppc0                             1          0
>> irq8: rtc                         288300          1
>> irq11: atapci1                    637852          2
>> irq12: vr0 uhci0+                3890833         15
>> irq13: npx0                            1          0
>> irq14: ata0                           54          0
>> Total                           29947281        119
> 
> Hmm.. There seems to be nothing wrong with these numbers. If you were 
> suffering from an interrupt storm I would have expected much larger numbers 
> in the "rate" column. The column "rate" shows the average number of 
> interrupts / second. In total your system handles about 120 interrupts / 
> second, so that shouldn't be a problem.
> Are you using "powerd" perhaps? Could it be that your system goes into a too 
> deep sleep state where interrupt handling costs significantly more time?
> 
> grtz,
> Daan
> 
> 
>