On Tue, Aug 20, 2024 at 3:50 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> On Tue, Aug 20, 2024 at 1:51 PM Arnaldo Carvalho de Melo
> <acme@xxxxxxxxxx> wrote:
> >
> > On Tue, Aug 20, 2024 at 08:45:03AM -0700, Namhyung Kim wrote:
> > > +++ b/tools/perf/builtin-report.c
> > > @@ -795,8 +795,13 @@ static int count_lost_samples_event(const struct perf_tool *tool,
> > >
> > > evsel = evlist__id2evsel(rep->session->evlist, sample->id);
> > > if (evsel) {
> > > - hists__inc_nr_lost_samples(evsel__hists(evsel),
> > > - event->lost_samples.lost);
> > > + struct hists *hists = evsel__hists(evsel);
> > > + u32 count = event->lost_samples.lost;
> > > +
> > > + if (event->header.misc & PERF_RECORD_MISC_LOST_SAMPLES_BPF)
> > > + hists__inc_nr_dropped_samples(hists, count);
> >
> > So this is inconsistent, we call it sometimes "lost", sometines
> > "dropped", I think we should make it consistent and call it "dropped",
> > because its not like it was "lost" because we didn't have the required
> > resources, memory, ring buffer being full, etc, i.e. the semantic
> > associated with PERF_RECORD_LOST.
> >
> > I.e. LOST is non intentional, not expected, DROPPED is the result of the
> > user _asking_ for something to be trown away, to be filtered, its
> > expected behaviour, there is value in differentiating one from the
> > other.
>
> Yep, that's because it's piggybacking on PERF_RECORD_LOST_SAMPLES.
> Do you want me to add a new (user) record format for dropped samples?
Ok, I have a related issue with AMD IBS. I'll start a new discussion
in a different thread. I think you can take patch 1 and 3 in this series
as they are not controversial, right?
Thanks,
Namhyung
