Re: Rescheduling interrupts

[Vegard Nossum]

Hi,

On Tue, Jan 22, 2008 at 6:05 PM, Ingo Molnar <mingo@xxxxxxx> wrote:
>
>  * S.ÃaÄlar Onur <caglar@xxxxxxxxxxxxx> wrote:
>
>
> > > My theory is that for whatever reason we get "repeat" IPIs: multiple
>  > > reschedule IPIs although the other CPU only initiated one.
>  >
>  > Ok, please see http://cekirdek.pardus.org.tr/~caglar/dmesg.3rd :)
>
>  hm, the IPI sending and receiving is nicely paired up:
>
>  [  625.795008] IPI (@smp_reschedule_interrupt) from task swapper:0 on CPU#1:
>  [  625.795223] IPI (@native_smp_send_reschedule) from task amarokapp:2882 on CPU#1:
>
>  amarokapp does wake up threads every 20 microseconds - that could
>  explain it. It's probably Xorg running on one core, amarokapp on the
>  other core. That's already 100 reschedules/sec.

Was this IPI thing ever resolved/fixed? I'm seeing the exact same
thing on my newest Fedora 8 kernel (2.6.24.5-85.fc8) now:

  33.3% (334.0)      <kernel IPI> : Rescheduling interrupts

And I know for sure that this did not show up a couple of months back.

If the cause of this is known, please let me know about it. If it
isn't, I will start a bisect run now :-)

Thanks.


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
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disguises that the error is the programmer's own creation."
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