Em Thu, Oct 19, 2017 at 05:21:27PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Oct 03, 2017 at 10:22:34PM +0800, Jin Yao escreveu: > > In perf record, it's walked on all samples yet. So it's very easy to get > > You're saying that perf record walks all samples always? That only > happens when we generate the build-id table, right? And people disable > that to speed up the process, knowing that some limitations will come > from that, for doing analysis right after running it is mostly OK to > disable the build-id processing.
So either you add a new option that processes all events without doing build-id processing (and all the locking, struct thread, map, etc processing it entails) and just looks at the sample->time, and when build id processing is enabled, just do as you're doing in this patch, then, at perf report --time you should look to see if those start/end times were filled in and if not tell that to the user, i.e. that either --record-time-boundaries (or a better name :-) ) has to be used, or, that build-id process, with a short explanation that --record-time-boundaries is a bit cheaper. - Arnaldo > - Arnaldo > > > the first/last samples and save the time to perf file header via the > > function write_sample_time(). > > > > In later, perf report/script will fetch the time from perf file header. > > > > Change log: > > ----------- > > v3: Remove the definitions of first_sample_time and last_sample_time > > from struct record and directly save them in perf_evlist. > > > > Signed-off-by: Jin Yao <[email protected]> > > --- > > tools/perf/builtin-record.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > > index 9b379f3..d5b78449 100644 > > --- a/tools/perf/builtin-record.c > > +++ b/tools/perf/builtin-record.c > > @@ -488,6 +488,11 @@ static int process_sample_event(struct perf_tool *tool, > > > > rec->samples++; > > > > + if (rec->evlist->first_sample_time == 0) > > + rec->evlist->first_sample_time = sample->time; > > + > > + rec->evlist->last_sample_time = sample->time; > > + > > return build_id__mark_dso_hit(tool, event, sample, evsel, machine); > > } > > > > -- > > 2.7.4
