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

[tingwei@codeaurora.org]

On 2020-07-22 00:37, Steven Rostedt wrote:
> 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
> 

Thanks, Steve. I'll fix this.

> 
>>  /*
>>   * 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,