Re: High interrupt CPU usage in top

[Mark Cullen <mark.r.cullen@xxxxxxxxx>]

Mark Cullen wrote:
> Oliver Fromme wrote:
>
> > Mark Cullen <mark.r.cullen@xxxxxxxxx> wrote:
> >  > Taken when the interrupt in top was at 22%, building world:
> >  >  > 320 total
> >  > 279 clk
> >  > 37  fxp0
> >  > 4   ata1
> >  >  > Taken when the interrupt in top was at 5%, still building world:
> >  >  > 288 total
> >  > 281 clk
> >  > 7   fxp0
> >  >     ata1
> >  >  > Watching it in real-time there are some spikes where either fxp0 
> > or ata1  > will go up to about ~40-60, but it doesn't really seem to 
> > relate to the  > number seen in top if you ask me...
> >
> > All of that looks quite normal.  It certainly shouldn't
> > account for a significant CPU interrupt percentage.
> > Either top(1) is lying, or something else is fishy.
> >
> > Best regards
> >    Oliver
>
> They were taken with systat as per Danials suggestion by the way, and I 
> noticed afterwards it actually shows CPU states like top, slightly 
> different from top, probably just due to the different times they were 
> started and stuff, but still didn't really seem to relate to the 
> relatively high number.
>
> I have noticed that INVARIANTS is in the GENERIC kernel config, might 
> that have anything to do with it?

Well, world and kernel just finished compiling, without INVARIANTS, and 
there's no difference. Infact, it seems worse... but it's probably the 
same. I guess I should keep INVARIANTS in for debugging in case of panics?

http://img198.imageshack.us/img198/1571/interrupt3eg.jpg

40% and very few interrupts? That was just starting out compiling 
`mysql4-server`.