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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-12 16:53:38 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-12 16:53:38 +1000 |
| commit | bc47ab0241c7c86da4f5e5f82fbca7d45387c18d (patch) | |
| tree | b9c33ae8b6de43e44cc5fcbaa3e4a15f18a5ed42 /Documentation/trace/power.txt | |
| parent | 37f9ef553bed630957e025504cdcbc76f5de49d5 (diff) | |
| parent | 8ebf975608aaebd7feb33d77f07ba21a6380e086 (diff) | |
Merge commit 'origin/master' into next
Manual merge of:
arch/powerpc/kernel/asm-offsets.c
Diffstat (limited to 'Documentation/trace/power.txt')
| -rw-r--r-- | Documentation/trace/power.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/trace/power.txt b/Documentation/trace/power.txt new file mode 100644 index 00000000000..cd805e16dc2 --- /dev/null +++ b/Documentation/trace/power.txt @@ -0,0 +1,17 @@ +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 |