Interrupt using all the CPU

[nocturnal]

Hi

kern.clockrate: { hz = 100, tick = 10000, profhz = 1024, stathz = 128 }

I'm going to see if it's possible to disable USB from the BIOS later 
today, if not, can i disable the USB devices in the kernel?



Med vänliga hälsningar

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


Chuck Swiger wrote:
> Nikos Vassiliadis wrote:
>> On Monday 03 July 2006 14:06, Daan Vreeken [PA4DAN] wrote:
> [ ... ]
>>>> 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.
>>
>> I have the feeling that rate is calculated like this:
>> number of interrupts since boottime / seconds of uptime
> 
> OK.
> 
>> so, this won't help if his is having now an interrupt storm
>> while most of the time the system is interrupted ~ 120 times
>> per second
> 
> An interrupt storm on what, though?
> 
> The ~100 interrupts per second from the clock on IRQ0 are absolutely 
> normal with HZ=100; the only other candidate seems to be the combination 
> of vr0 & USB controller on IRQ 12.
> 
> If it's possible to disable the USB controller for a bit in the BIOS, it 
> would be interesting to see whether that makes any difference.  You can 
> probably kill the parallel port, too.
> 
> It's also interesting to note that IRQ 8, the RTC, seems to be mostly 
> idle-- normally that fires at stathz=128...check "sysctl kern.clockrate".
> 
>> systat -vmstat $time shows interrupts per second regarding the last 
>> $time seconds
> 
> Right, although the output from "vmstat 1" would survive being pasted 
> into email better, I suspect.
>