tracing: add "power-tracer": C/P state tracer to help power optimization
Impact: new "power-tracer" ftrace plugin
This patch adds a C/P-state ftrace plugin that will generate
detailed statistics about the C/P-states that are being used,
so that we can look at detailed decisions that the C/P-state
code is making, rather than the too high level "average"
that we have today.
An example way of using this is:
mount -t debugfs none /sys/kernel/debug
echo cstate > /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/trace/cstate.pl > out.svg
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3abd645..4c45377 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -28,6 +28,7 @@
TRACE_FN_RET,
TRACE_USER_STACK,
TRACE_BTS,
+ TRACE_POWER,
__TRACE_LAST_TYPE
};
@@ -160,6 +161,11 @@
unsigned long to;
};
+struct trace_power {
+ struct trace_entry ent;
+ struct power_trace state_data;
+};
+
/*
* trace_flag_type is an enumeration that holds different
* states when a trace occurs. These are:
@@ -266,6 +272,7 @@
IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\
+ IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
__ftrace_bad_type(); \
} while (0)