Latest intr problems

John Baldwin jhb at
Mon Aug 23 12:40:36 UTC 2010

On Saturday, August 21, 2010 11:28:41 am Andriy Gapon wrote:
> on 21/08/2010 16:04 b. f. said the following:
> > Andriy Gapon wrote:
> >> on 21/08/2010 12:35 Andriy Gapon said the following:
> >>> I feel like you might be having a problem with clocks...
> >> FWIW, I am reading this document
> >> and I see this sentence: "All of the clocks in the processor core are
> >> stopped in the C3 state".
> >>
> >> I see that you have C3 state enabled and it's regularly entered:
> >> dev.cpu.0.cx_usage: 0.00% 5.51% 94.48% last 305us
> > 
> > I don't think this accounts for all of his problems, unless his
> > machine has an unusual configuration. 
> Well, let's try to not muddy the waters prematurely.

It could easily account for it.  If the lapic is going to sleep in C3, then 
you are actually missing statclock interrupts and likely screwing up the 
accounting (idle threads wouldn't accumulate "time" correctly for example).  
Even though his system really isn't spending a lot of time executing 
interrupts, the cp_time[] values would be skewed and wrong.

John Baldwin

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