Re: [PATCH 5/8] trace: Convert the power tracer into an event tracer

[Li Zefan <lizf@cn.fujitsu.com>]

Arjan van de Ven wrote:
>>From f591a0f126263733d606838a5d113b9807b12c84 Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <arjan@linux.intel.com>
> Date: Sat, 12 Sep 2009 07:53:03 +0200
> Subject: [PATCH] trace: Convert the power tracer into an event tracer
> 
> This patch converts the existing power tracer into an event tracer,
> so that power events (C states and frequency changes) can be tracked
> via "perf".
> 
> This also removes the perl script that was used to demo the tracer;
> its functionality is being replaced entirely with timechart.
> 

And Documentation/power.txt needs update, or just remove it?

> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

...

> diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
> new file mode 100644
> index 0000000..cb4fc51
> --- /dev/null
> +++ b/kernel/trace/power-traces.c

This file is not necessarily needed.

You can just add definition of CREATE_TRACE_POINTS in process.c.

> @@ -0,0 +1,18 @@
> +/*
> + * Power trace points
> + *
> + * Copyright (C) 2009 Arjan van de Ven <arjan@linux.intel.com>
> + */
> +
> +#include <linux/string.h>
> +#include <linux/types.h>
> +#include <linux/workqueue.h>
> +#include <linux/sched.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/power.h>
> +
> +EXPORT_TRACEPOINT_SYMBOL_GPL(power_start);
> +

I think it's power_frequency that needs to be exported?