Re: [.32-rc3] scheduler: iwlagn consistently high in "waiting for CPU"

From: Frans Pop
Date: Wed Oct 07 2009 - 14:36:30 EST


On Wednesday 07 October 2009, Frans Pop wrote:
> On Tuesday 06 October 2009, Frans Pop wrote:
> > I've checked for 2.6.31.1 now and iwlagn is listed high there too when
> > the system is idle, but with normal values of 60-100 ms. And phy0 has
> > normal values of below 10 ms.
> > I've now rebooted with today's mainline git; phy0 now frequently shows
> > with values of around 100 ms too (i.e. higher than last time).
>
> Mike privately sent me a script to try to capture the latencies with
> perf, but the perf output does not show any high latencies at all. It
> looks as if we may have found a bug in latencytop here instead.

Not sure if it's relevant nor what it means, but I frequently see two lines
for iwlagn, e.g:

Scheduler: waiting for cpu 102.4 msec 99.7 %
. 3.3 msec 0.3 %

I get the same results with both latencytop 0.4 and 0.5.
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