Merge branch 'sh/dwarf-unwinder' of git://github.com/mfleming/linux-2.6 into sh/dwarf...
[pandora-kernel.git] / Documentation / trace / power.txt
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