[PATCH, RFC 3/3] tracing: Add documentation for the power tracer

From: Theodore Ts'o
Date: Sat Apr 11 2009 - 16:30:12 EST


Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Steven Rostedt <srostedt@xxxxxxxxxx>
---
Documentation/power.txt | 19 +++++++++++++++++++
1 files changed, 19 insertions(+), 0 deletions(-)
create mode 100644 Documentation/power.txt

diff --git a/Documentation/power.txt b/Documentation/power.txt
new file mode 100644
index 0000000..16f95c9
--- /dev/null
+++ b/Documentation/power.txt
@@ -0,0 +1,19 @@
+The power trace 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
+
+
--
1.5.6.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/