Re: [PATCH v3 04/10] cxl: add common function to disable event trace

[Dave Jiang <dave.jiang@intel.com>]

On 11/2/2022 11:02 PM, Steven Rostedt wrote:
> On Wed, 02 Nov 2022 14:20:26 -0700
> Dave Jiang <dave.jiang@intel.com> wrote:
> 
>> Add a common function for cxl command that disables the event trace for the
>> instance created.
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>   cxl/event_trace.c |    8 ++++++++
>>   cxl/event_trace.h |    1 +
>>   2 files changed, 9 insertions(+)
>>
>> diff --git a/cxl/event_trace.c b/cxl/event_trace.c
>> index d59e54c33df6..bcd4f8b2968e 100644
>> --- a/cxl/event_trace.c
>> +++ b/cxl/event_trace.c
>> @@ -221,3 +221,11 @@ int cxl_event_tracing_enable(struct tracefs_instance *inst, const char *system)
>>   	tracefs_trace_on(inst);
>>   	return 0;
>>   }
>> +
>> +int cxl_event_tracing_disable(struct tracefs_instance *inst)
>> +{
>> +	if (!tracefs_trace_is_on(inst))
>> +		return 0;
> 
> Why bother checking if tracing is on or not. It's not any more
> efficient. You're not eliminating a system call. You are actually
> adding another one.

Ok, will remove.
> 
> -- Steve
> 
> 
>> +
>> +	return tracefs_trace_off(inst);
>> +}
>> diff --git a/cxl/event_trace.h b/cxl/event_trace.h
>> index 0258b8dc65a3..17d922f922c1 100644
>> --- a/cxl/event_trace.h
>> +++ b/cxl/event_trace.h
>> @@ -21,5 +21,6 @@ struct event_ctx {
>>   
>>   int cxl_parse_events(struct tracefs_instance *inst, struct event_ctx *ectx);
>>   int cxl_event_tracing_enable(struct tracefs_instance *inst, const char *system);
>> +int cxl_event_tracing_disable(struct tracefs_instance *inst);
>>   
>>   #endif
>>
>