[deliverable/linux.git] / Documentation / trace / power.txt

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
Commit	Line	Data
56c49951 TT	1	The power tracer collects detailed information about C-state and P-state
	2	transitions, instead of just looking at the high-level "average"
	3	information.
	4
	5	There is a helper script found in scrips/tracing/power.pl in the kernel
	6	sources which can be used to parse this information and create a
	7	Scalable Vector Graphics (SVG) picture from the trace data.
	8
	9	To use this tracer:
	10
	11	echo 0 > /sys/kernel/debug/tracing/tracing_enabled
	12	echo power > /sys/kernel/debug/tracing/current_tracer
	13	echo 1 > /sys/kernel/debug/tracing/tracing_enabled
	14	sleep 1
	15	echo 0 > /sys/kernel/debug/tracing/tracing_enabled
	16	cat /sys/kernel/debug/tracing/trace \| \
	17	perl scripts/tracing/power.pl > out.sv