Re: [RFC][PATCH 06/14] fgraph: Move function graph specific code into fgraph.c

[Masami Hiramatsu <mhiramat@kernel.org>]

On Thu, 22 Nov 2018 22:11:33 -0800
Joel Fernandes <joel@joelfernandes.org> wrote:

> On Wed, Nov 21, 2018 at 08:27:14PM -0500, Steven Rostedt wrote:
> > From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> > 
> > To make the function graph infrastructure more managable, the code needs to
> > be in its own file (fgraph.c). Move the code that is specific for managing
> > the function graph infrastructure out of ftrace.c and into fgraph.c
> > 
> > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> 
> I think this patch causes a build error if CONFIG_FUNCTION_PROFILER is
> disabled but function graph is enabled. The following diff fixes it for me.

Good catch, I also confirmed it.

I think we'd better to define an empty stub of ftrace_graph_graph_time_control(enable)
in trace.h instead, since fgraph_graph_time is not used if CONFIG_FUNCTION_PROFILER=n.

Thank you,

> 
> thanks,
> 
>  - Joel
> 
>  ----8<------
>  
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 3b8c307c7ff0..ce38bb962f91 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -382,6 +382,15 @@ static void ftrace_update_pid_func(void)
>  	update_ftrace_function();
>  }
>  
> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> +static bool fgraph_graph_time = true;
> +
> +void ftrace_graph_graph_time_control(bool enable)
> +{
> +	fgraph_graph_time = enable;
> +}
> +#endif
> +
>  #ifdef CONFIG_FUNCTION_PROFILER
>  struct ftrace_profile {
>  	struct hlist_node		node;
> @@ -783,12 +792,6 @@ function_profile_call(unsigned long ip, unsigned long parent_ip,
>  }
>  
>  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> -static bool fgraph_graph_time = true;
> -
> -void ftrace_graph_graph_time_control(bool enable)
> -{
> -	fgraph_graph_time = enable;
> -}
>  
>  static int profile_graph_entry(struct ftrace_graph_ent *trace)
>  {


-- 
Masami Hiramatsu <mhiramat@kernel.org>