perf report: Add option to show total period

Just like --show-nr-samples, to help in diagnosing problems in the
tools.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-1lr7ejdjfvy2uwy2wkmatcpq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 24cca0a..32c9086 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -664,6 +664,13 @@
 			ret += snprintf(s + ret, size - ret, "%11" PRIu64, nr_events);
 	}
 
+	if (symbol_conf.show_total_period) {
+		if (sep)
+			ret += snprintf(s + ret, size - ret, "%c%" PRIu64, *sep, period);
+		else
+			ret += snprintf(s + ret, size - ret, " %12" PRIu64, period);
+	}
+
 	if (pair_hists) {
 		char bf[32];
 		double old_percent = 0, new_percent = 0, diff;
@@ -770,6 +777,13 @@
 			fputs("  Samples  ", fp);
 	}
 
+	if (symbol_conf.show_total_period) {
+		if (sep)
+			ret += fprintf(fp, "%cPeriod", *sep);
+		else
+			ret += fprintf(fp, "   Period    ");
+	}
+
 	if (symbol_conf.show_cpu_utilization) {
 		if (sep) {
 			ret += fprintf(fp, "%csys", *sep);
@@ -834,6 +848,8 @@
 	fprintf(fp, "# ........");
 	if (symbol_conf.show_nr_samples)
 		fprintf(fp, " ..........");
+	if (symbol_conf.show_total_period)
+		fprintf(fp, " ............");
 	if (pair) {
 		fprintf(fp, " ..........");
 		if (show_displacement)
@@ -917,6 +933,9 @@
 	if (symbol_conf.show_nr_samples)
 		ret += 11;
 
+	if (symbol_conf.show_total_period)
+		ret += 13;
+
 	list_for_each_entry(se, &hist_entry__sort_list, list)
 		if (!se->elide)
 			ret += 2 + hists__col_len(hists, se->se_width_idx);