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, 4 insertions, 4 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f13cda1..b8f47de 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -138,14 +138,14 @@ static int add_event_total(struct perf_session *session,
 	if (!hists)
 		return -ENOMEM;
 
-	hists->stats.total += data->period;
+	hists->stats.total_period += data->period;
 	/*
 	 * FIXME: add_event_total should be moved from here to
 	 * perf_session__process_event so that the proper hist is passed to
 	 * the event_op methods.
 	 */
 	hists__inc_nr_events(hists, PERF_RECORD_SAMPLE);
-	session->hists.stats.total += data->period;
+	session->hists.stats.total_period += data->period;
 	return 0;
 }
 
@@ -322,10 +322,10 @@ static int __cmd_report(void)
 			if (rb_first(&session->hists.entries) ==
 			    rb_last(&session->hists.entries))
 				fprintf(stdout, "# Samples: %Ld\n#\n",
-					hists->stats.total);
+					hists->stats.total_period);
 			else
 				fprintf(stdout, "# Samples: %Ld %s\n#\n",
-					hists->stats.total,
+					hists->stats.total_period,
 					__event_name(hists->type, hists->config));
 
 			hists__fprintf(hists, NULL, false, stdout);