perf hist: Clarify events_stats fields usage

The events_stats.total field is too generic, rename it to .total_period,
and also add a comment explaining that it is the sum of all the .period
fields in samples, that is needed because we use auto-freq to avoid
sampling artifacts.

Ditto for events_stats.lost, that is the sum of all lost_event.lost
fields, i.e. the number of events the kernel dropped.

Looking at the users, builtin-sched.c can make use of these fields and
stop doing it again.

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 3a95a0260a5b..6dd4bdae8a87 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -54,7 +54,7 @@ static int diff__process_sample_event(event_t *event, struct perf_session *sessi
                 return -1;
         }
 
-        session->hists.stats.total += data.period;
+        session->hists.stats.total_period += data.period;
         return 0;
 }