Re: [PATCH 2/3] ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip

[Steven Rostedt]

On Fri, 20 Jan 2017 11:44:46 +0900
Namhyung Kim <namhyung@xxxxxxxxxx> wrote:


> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -787,6 +787,20 @@ extern void __trace_graph_return(struct trace_array *tr,
>  				 struct ftrace_graph_ret *trace,
>  				 unsigned long flags, int pc);
>  
> +struct ftrace_hash {
> +	unsigned long		size_bits;
> +	struct hlist_head	*buckets;
> +	unsigned long		count;
> +	struct rcu_head		rcu;
> +};
> +
> +struct ftrace_func_entry *
> +ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
> +
> +static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
> +{
> +	return !hash || !hash->count;
> +}

Note, I had to modify this patch and move this declaration outside of
the #ifdef CONFIG_FUNCTION_GRAPH_TRACER, as it failed to build when
function graph wasn't enabled. Function tracer uses this too.

-- Steve

>  
>  #ifdef CONFIG_DYNAMIC_FTRACE
>  /* TODO: make this variable */