diff options
| author | James Bottomley <James.Bottomley@HansenPartnership.com> | 2009-06-12 10:02:03 -0500 |
|---|---|---|
| committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2009-06-12 10:02:03 -0500 |
| commit | 82681a318f9f028ea64e61f24bbd9ac535531921 (patch) | |
| tree | 529b6a5b4fd040fb54b7672b1a224ebd47445876 /Documentation/trace/power.txt | |
| parent | 3860c97bd60a4525bb62eb90e3e7d2f02662ac59 (diff) | |
| parent | 8ebf975608aaebd7feb33d77f07ba21a6380e086 (diff) | |
[SCSI] Merge branch 'linus'
Conflicts:
drivers/message/fusion/mptsas.c
fixed up conflict between req->data_len accessors and mptsas driver updates.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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 |