Re: [Bug #12465] KVM guests stalling on 2.6.28 (bisected)

From: Ingo Molnar
Date: Mon Jan 26 2009 - 10:01:41 EST



* Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:

> Is there a way to add a wall-time column to this output so that we can
> see where the time goes?

yes, on tip/master:

http://people.redhat.com/mingo/tip.git/README

do something like this:

echo funcgraph-abstime > /debug/tracing/trace_options

when the function-graph plugin is active. This will activate the absolute
timestamps column in the trace output.

> Another something nice would be to have ctx switches like:
>
> foo-1 => bar-2 ran: ${time foo spend on the cpu} since: ${time bar spend away from the cpu}
>
> I'll poke me a little at this function graph tracer thingy to see if I
> can do that.

indeed, tracking the 'scheduling atom duration' would be very nice.

Ingo
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