The power tracer collects detailed information about C-state and P-state
transitions, instead of just looking at the high-level "average"
information.

There is a helper script found in scrips/tracing/power.pl in the kernel
sources which can be used to parse this information and create a
Scalable Vector Graphics (SVG) picture from the trace data.

To use this tracer:

	echo 0 > /sys/kernel/debug/tracing/tracing_enabled
	echo power > /sys/kernel/debug/tracing/current_tracer
	echo 1 > /sys/kernel/debug/tracing/tracing_enabled
	sleep 1
	echo 0 > /sys/kernel/debug/tracing/tracing_enabled
	cat /sys/kernel/debug/tracing/trace | \
		perl scripts/tracing/power.pl > out.sv
