Re: [PATCH 2/4] tracing: add trace_export support for event trace

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 20 Jul 2020 10:21:15 +0800
Tingwei Zhang <tingwei@codeaurora.org> wrote:

> Only function traces can be exported to other destinations currently.
> This patch exports event trace as well.
> 
> Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
> ---
>  kernel/trace/trace.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index bb62269724d5..aef6330836e2 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -2697,17 +2697,6 @@ int tracepoint_printk_sysctl(struct ctl_table *table, int write,
>  	return ret;
>  }
>  
> -void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
> -{
> -	if (static_key_false(&tracepoint_printk_key.key))
> -		output_printk(fbuffer);
> -
> -	event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer,
> -				    fbuffer->event, fbuffer->entry,
> -				    fbuffer->flags, fbuffer->pc, fbuffer->regs);
> -}
> -EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
> -

Please move the ftrace_exports routines up, instead of moving the
trace_event_buffer_commit() down. As it fits better where it is (next
to the other buffer_commit code).

-- Steve


>  /*
>   * Skip 3:
>   *
> @@ -2868,6 +2857,19 @@ int unregister_ftrace_export(struct
> trace_export *export) }
>  EXPORT_SYMBOL_GPL(unregister_ftrace_export);
>  
> +void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
> +{
> +	if (static_key_false(&tracepoint_printk_key.key))
> +		output_printk(fbuffer);
> +
> +	if (static_branch_unlikely(&ftrace_exports_enabled))
> +		ftrace_exports(fbuffer->event);
> +	event_trigger_unlock_commit_regs(fbuffer->trace_file,
> fbuffer->buffer,
> +				    fbuffer->event, fbuffer->entry,
> +				    fbuffer->flags, fbuffer->pc,
> fbuffer->regs); +}
> +EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
> +
>  void
>  trace_function(struct trace_array *tr,
>  	       unsigned long ip, unsigned long parent_ip, unsigned
> long flags,