CPU time accounting broken on 8-STABLE machine after a few hours of uptime

[Don Lewis]

On 29 Sep, Andriy Gapon wrote:
> on 29/09/2010 00:11 Don Lewis said the following:
>> On 28 Sep, Don Lewis wrote:
>> 
>> 
>>> % vmstat -i
>>> interrupt                          total       rate
>>> irq0: clk                       60683442       1000
>>> irq1: atkbd0                           6          0
>>> irq8: rtc                        7765537        127
>>> irq9: acpi0                           13          0
>>> irq10: ohci0 ehci1+             10275064        169
>>> irq11: fwohci0 ahc+               132133          2
>>> irq12: psm0                           21          0
>>> irq14: ata0                        90982          1
>>> irq15: nfe0 ata1                   18363          0
>>>
>>> I'm not sure why I'm getting USB interrupts.  There aren't any USB
>>> devices plugged into this machine.
>> 
>> Answer: irq 10 is also shared by vgapci0 and atapci1.
> 
> Just curious why Local APIC timer isn't being used for hardclock on your system.

I'm using the same kernel config as the one on a slower !SMP box which
I'm trying to squeeze as much performance out of as possible.  My kernel
config file contains these statements:
	nooptions       SMP
	nodevice        apic

Testing with an SMP kernel is on my TODO list.