Messages in this thread | | | Date | Tue, 28 Oct 2008 11:04:03 +0100 | From | Ingo Molnar <> | Subject | Re: PATCH] ftrace: Add a C/P state tracer to help power optimization |
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* Arjan van de Ven <arjan@infradead.org> wrote:
> 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....
correct.
Ingo
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