Re: [PATCH 3/5] tracing: save one trace_event->type by using __TRACE_LAST_TYPE

[Steven Rostedt <rostedt@goodmis.org>]

On Fri,  3 Jul 2020 10:06:10 +0800
Wei Yang <richard.weiyang@linux.alibaba.com> wrote:

> Static defined trace_event->type stops at (__TRACE_LAST_TYPE - 1) and
> dynamic trace_event->type starts from (__TRACE_LAST_TYPE + 1).
> 
> To save one trace_event->type index, let's use __TRACE_LAST_TYPE.

When I wrote this code, I purposely had a gap there. But I guess it's
not really needed. I'll take your patch.

Thanks,

-- Steve


> 
> Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
> ---
>  kernel/trace/trace_output.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index b704b3ef4264..818f0c9d10c5 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -20,7 +20,7 @@ DECLARE_RWSEM(trace_event_sem);
>  
>  static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
>  
> -static int next_event_type = __TRACE_LAST_TYPE + 1;
> +static int next_event_type = __TRACE_LAST_TYPE;
>  
>  enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
>  {
> @@ -675,7 +675,7 @@ static LIST_HEAD(ftrace_event_list);
>  static int trace_search_list(struct list_head **list)
>  {
>  	struct trace_event *e;
> -	int next = __TRACE_LAST_TYPE + 1;
> +	int next = __TRACE_LAST_TYPE;
>  
>  	if (list_empty(&ftrace_event_list)) {
>  		*list = &ftrace_event_list;