On Thu, Jan 18, 2018 at 10:43:18AM +0100, Jiri Olsa wrote:
> On Wed, Jan 17, 2018 at 12:48:12AM +0800, Wang YanQing wrote:
> > On Mon, Jan 15, 2018 at 11:06:11AM +0100, Jiri Olsa wrote:
> > > On Mon, Jan 15, 2018 at 12:47:32PM +0800, Wang YanQing wrote:
> > > > So that beautifiers wanting to resolve kernel function addresses to
> > > > names can do its work, and when we use "perf report" for output of
> > > > "perf kmem record", we will get kernel symbol output.
> > > >
> > > > Signed-off-by: Wang YanQing <udkni...@gmail.com>
> > > > ---
> > > > tools/perf/builtin-report.c | 9 +++++++++
> > > > 1 file changed, 9 insertions(+)
> > > >
> > > > diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> > > > index dd4df9a..7b65100 100644
> > > > --- a/tools/perf/builtin-report.c
> > > > +++ b/tools/perf/builtin-report.c
> > > > @@ -1317,6 +1317,15 @@ int cmd_report(int argc, const char **argv)
> > > > report.range_num = 1;
> > > > }
> > > >
> > > > + if (session->tevent.pevent &&
> > > > + pevent_set_function_resolver(session->tevent.pevent,
> > > > + machine__resolve_kernel_addr,
> > > > + &session->machines.host) < 0) {
> > > > + pr_err("%s: failed to set libtraceevent function
> > > > resolver\n",
> > > > + __func__);
> > > > + return -1;
> > > > + }
> > >
> > > why not calling the wrapper trace_event__register_resolver?
> > The reason is the same as builtin-script doesn't use
> > trace_event__register_resolver,
> > because we only use report and script to analyze offline perf.data, and
> > there could
> > be no tracepoints in perf.data.
>
> hum, I missed this functionality.. so we need this even if there
> are no tracepoints in the perf.data?
In "perf report", when there are tracepoints in perf.data,
session->tevent.pevent
will be initialized in trace-event-read.c:trace_report, then "if
(session->tevent.pevent"
will become true, and we should calling pevent_set_function_resolver.
But if we calling trace_event__register_resolver, then it will initialize
tevent.pevent
no matter whether there are tracepoints in perf.data.
Thanks.
>
> The only related interface function I could found is pevent_find_function
> and it seems to be called only from within traceevent library.
>
> thanks,
> jirka
