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

[Josef Bacik]

On 03/26/2014 03:27 PM, David Ahern wrote:
> 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://urldefense.proofpoint.com/v1/url?u=https://lkml.org/lkml/2013/11/30/63&k=ZVNjlDMF0FElm4dQtryO4A%3D%3D%0A&r=cKCbChRKsMpTX8ybrSkonQ%3D%3D%0A&m=kB8XhiqkBzGE%2BTCnMhkJQP%2BjerKZ5bWPi%2BqGVVwGKPg%3D%0A&s=c232c9e9ea4eb35f56ba43dd8e7e70589e016430a7b4a5a89f7c938d05bd7b7a

Argh sorry I was testing on my tree but I'm still 3.13 based.  Thanks,

Josef

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