Re: [PATCH] new irq tracer

[Masami Hiramatsu <mhiramat@redhat.com>]

KOSAKI Motohiro wrote:
>>  /**
>>   * handle_IRQ_event - irq action chain handler
>>   * @irq:	the interrupt number
>> @@ -354,7 +358,9 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
>>  		local_irq_enable_in_hardirq();
>>  
>>  	do {
>> +		trace_irq_entry(irq);
>>  		ret = action->handler(irq, action->dev_id);
>> +		trace_irq_exit(irq, ret);
>>  		if (ret == IRQ_HANDLED)
>>  			status |= action->flags;
>>  		retval |= ret;
> 
> Nobdy want unnecessary redundant tracepoint.
> Please discuss with mathieu, and merge his tracepoint.

Hmm, from the viewpoint of trouble shooting, the place of LTTng's tracepoint
is enough. However, from the same viewpoint, it should pass irq-number
to irq-exit event too, because we may lost some previous events by buffer-overflow
etc.

         trace_irq_entry(irq, NULL);
         ret = _handle_IRQ_event(irq, action);
         trace_irq_exit(irq, ret);
                        ^^^^

Thank you,

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com