Re: [PATCH] perf: make perf script actually spit out backtraces for events

[David Ahern]

On 3/26/14, 12:57 PM, Josef Bacik wrote:
> We are trying to debug a problem internally and noticed that if we use perf
> record -g -e <tracepoint> and then try to use perf script to get the events and
> their backtraces that we weren't getting the backtraces, even though they were
> collected and would show up with perf report.  For some reason the tracepoint
> print stuff didn't have the right things set in order to print out backtraces.
> I have no idea why this is as adding them in there makes the backtraces come out
> properly, and if we don't use the -g option perf script still acts properly with
> those options set.  Hopefully this is the correct fix, it has fixed the problem
> for us.  Thanks,

You can manually request fields using the -f option.

That said ...

> Signed-off-by: Josef Bacik <jbacik@xxxxxx>
> ---
> NOTE: I looked at MAINTAINERS to see if there was a perf list and it didn't look
> like there was one, sorry if this is the wrong place to send patches to.
>
>   tools/perf/builtin-script.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index baf1798..6d14c06 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -99,7 +99,9 @@ static struct {
>
>   		.fields = PERF_OUTPUT_COMM | PERF_OUTPUT_TID |
>   				  PERF_OUTPUT_CPU | PERF_OUTPUT_TIME |
> -				  PERF_OUTPUT_EVNAME | PERF_OUTPUT_TRACE,
> +				  PERF_OUTPUT_EVNAME | PERF_OUTPUT_TRACE |
> +				  PERF_OUTPUT_IP | PERF_OUTPUT_SYM |
> +				  PERF_OUTPUT_DSO,

A change has been applied to upstream:
https://lkml.org/lkml/2013/11/30/63


David

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