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| author | Theodore Ts'o <tytso@mit.edu> | 2009-04-11 21:51:19 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-12 14:51:42 +0200 |
| commit | 56c49951747f250d8398582509e02ae5ce1d36d1 (patch) | |
| tree | 24ce4afcf9bb96593f6fe8afb488f0e38b04bfe8 /Documentation/trace | |
| parent | tracing, net, skb tracepoint: make skb tracepoint use the TRACE_EVENT() macro (diff) | |
| download | linux-56c49951747f250d8398582509e02ae5ce1d36d1.tar.xz linux-56c49951747f250d8398582509e02ae5ce1d36d1.zip | |
tracing: Add documentation for the power tracer
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <1239479479-2603-4-git-send-email-tytso@mit.edu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/trace')
| -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 000000000000..cd805e16dc27 --- /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 |