Re: How to write marker info in MMIO trace from kernel

[Larry Finger <Larry.Finger@lwfinger.net>]

On 05/04/2010 05:58 PM, Steven Rostedt wrote:
> On Tue, 2010-05-04 at 17:27 -0500, Larry Finger wrote:
> 
>> Thanks for the info. One other question - when I write only mmiotrace to
>> the current_tracer, the trace_printk() stuff does not end up in the
>> buffer. I can get it by using the "sysprof" tracer, but that has a lot
>> of stuff I do not want. Did I miss some configuration? My list of
>> available tracers is "blk kmemtrace mmiotrace wakeup_rt wakeup function
>> sysprof sched_switch nop".
> 
> Ug, that's because the mmiotrace handles its own prints and ignores
> anything it does not know about. Here, try this patch:
> 
> -- Steve
> 
> diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
> index 017fa37..8652f28 100644
> --- a/kernel/trace/trace_mmiotrace.c
> +++ b/kernel/trace/trace_mmiotrace.c
> @@ -282,7 +282,7 @@ static enum print_line_t mmio_print_line(struct trace_iterator *iter)
>  	case TRACE_PRINT:
>  		return mmio_print_mark(iter);
>  	default:
> -		return TRACE_TYPE_HANDLED; /* ignore unknown entries */
> +		return TRACE_TYPE_UNHANDLED;
>  	}
>  }

That did the trick.

Thanks a lot,

Larry