Re: [PATCH 3/4] tracing: Improve message of empty set_ftrace_notrace file

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 13 Jun 2014 01:23:52 +0900
Namhyung Kim <namhyung@kernel.org> wrote:

> When there's no entry in set_ftrace_notrace, it'll print nothing, but
> it's better to print something like below like set_graph_notrace does:
> 
>   #### no functions disabled ####
> 
> Reported-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  kernel/trace/ftrace.c |   15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index b375cf2cd786..566ffa0f3442 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -2603,6 +2603,16 @@ static void *t_start(struct seq_file *m, loff_t *pos)
>  		return iter;
>  	}
>  
> +	if (iter->flags & FTRACE_ITER_NOTRACE &&
> +	    ftrace_hash_empty(ops->notrace_hash)) {
> +		if (*pos > 0)
> +			return t_hash_start(m, pos);
> +		iter->flags |= FTRACE_ITER_PRINTALL;
> +		/* reset in case of seek/pread */
> +		iter->flags &= ~FTRACE_ITER_HASH;
> +		return iter;
> +	}

This contains the exact if block as the condition before it. Why not
join the two:

	if ((iter->flags & FTRACE_ITER_FILTER &&
	     ftrace_hash_empty(ops->filter_hash))
	  ||
	    (iter->flags & FTRACE_ITER_NOTRACE &&
	     ftrace_hash_empty(ops->notrace_hash))) {

-- Steve

> +
>  	if (iter->flags & FTRACE_ITER_HASH)
>  		return t_hash_start(m, pos);
>  
> @@ -2639,7 +2649,10 @@ static int t_show(struct seq_file *m, void *v)
>  		return t_hash_show(m, iter);
>  
>  	if (iter->flags & FTRACE_ITER_PRINTALL) {
> -		seq_printf(m, "#### all functions enabled ####\n");
> +		if (iter->flags & FTRACE_ITER_NOTRACE)
> +			seq_printf(m, "#### no functions disabled ####\n");
> +		else
> +			seq_printf(m, "#### all functions enabled ####\n");
>  		return 0;
>  	}
>