Messages in this thread | | | Date | Mon, 6 Oct 2008 14:21:31 -0700 | From | Arjan van de Ven <> | Subject | Re: PATCH] ftrace: Add a C/P state tracer to help power optimization |
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> > the link between P states and frequency is... rather lose. > > Especially with Turbo Mode it no longer is really relevant to list > > frequencies. > > It would probably be less confusing for everyone if the higher level > cpufreq layers reported the correct frequency for turbo mode too. > I haven't checked how complicated this would be.
it's impossible until after the fact; you don't know which frequencies you got until you check back later.
> Ok. > > That means that when a CPU is idle forever there won't be any output?
correct; it'll wait until it stops being idle before telling you how long it was idle.
if it really bothers you we could do a dummy broadcast ipi on shutting down the tracer.. in practice it's not a problem. (we wake up all cpus all the time)
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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