Messages in this thread | | | Date | Mon, 27 Oct 2008 14:06:30 -0700 | From | Arjan van de Ven <> | Subject | Re: PATCH] ftrace: Add a C/P state tracer to help power optimization |
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On Mon, 27 Oct 2008 15:47:30 -0400 fche@redhat.com (Frank Ch. Eigler) wrote:
> > Arjan van de Ven <arjan@infradead.org> writes: > > > [...] > > --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > [...] > > @@ -427,6 +429,8 @@ static int acpi_cpufreq_target(struct > > cpufreq_policy *policy, } > > } > > > > + trace_power_mark(&it, POWER_PSTATE, next_perf_state); > > + > > switch (data->cpu_feature) { > > case SYSTEM_INTEL_MSR_CAPABLE: > > cmd.type = SYSTEM_INTEL_MSR_CAPABLE; > > [...] > > Is there some reason that this doesn't use tracepoints instead > of such a single-backend hook?
because it's a ton simpler this way? do simple things simpe and all that....
-- 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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