Commit-ID: 56c49951747f250d8398582509e02ae5ce1d36d1 Gitweb: http://git.kernel.org/tip/56c49951747f250d8398582509e02ae5ce1d36d1 Author: Theodore Ts'o <tytso@xxxxxxx> AuthorDate: Sat, 11 Apr 2009 15:51:19 -0400 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Sun, 12 Apr 2009 14:51:42 +0200 tracing: Add documentation for the power tracer Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> Acked-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Steven Rostedt <srostedt@xxxxxxxxxx> LKML-Reference: <1239479479-2603-4-git-send-email-tytso@xxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- 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 0000000..cd805e1 --- /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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html