Re: /proc/stat information incorrect

From: Martin Schwidefsky
Date: Fri Apr 20 2012 - 08:07:19 EST


On Tue, 17 Apr 2012 10:04:35 +0200
Bas van der Oest <bassvdo@xxxxxxxxx> wrote:

> > Assuming that you are on a recent kernel (>= 3.2), could you please
> > try to revoke git commit a25cac5198d4ff28 "proc: Consider NO_HZ when
> > printing idle and iowait times" and try again ?
>
> I revoked the patch and this certainly had effect, however I still
> doubt if the result is completely correct now.
> It now seems that CPU4 (this one is handling the irqs now) spends more
> time than the other CPUs:
>
> user nice system idle iowait irq softirq sum
> cpu 4 0 412 8186 0 0 79 8681
> cpu0 0 0 1 1074 0 0 1 1076
> cpu1 0 0 2 1075 0 0 0 1077
> cpu2 0 0 1 1075 0 0 0 1076
> cpu3 0 0 1 1079 0 0 0 1080
> cpu4 1 0 115 941 0 0 78 1135
> cpu5 2 0 99 984 0 0 0 1085
> cpu6 0 0 98 977 0 0 0 1075
> cpu7 0 0 95 980 0 0 0 1075
>
> Any suggestions where this small difference is coming from?

CONFIG_IRQ_TIME_ACCOUNTING comes to mind. Is this enabled for your
kernel ?

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

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