perf diff: Add --percentage option

The --percentage option is for controlling overhead percentage
displayed.  It can only receive either of "relative" or "absolute" and
affects -c delta output only.

For more information, please see previous commit same thing done to
"perf report".

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1397145720-8063-5-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 204fffe..c903fe1 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -220,7 +220,8 @@
 
 static double period_percent(struct hist_entry *he, u64 period)
 {
-	u64 total = he->hists->stats.total_period;
+	u64 total = hists__total_period(he->hists);
+
 	return (period * 100.0) / total;
 }
 
@@ -259,11 +260,18 @@
 static int formula_delta(struct hist_entry *he, struct hist_entry *pair,
 			 char *buf, size_t size)
 {
+	u64 he_total = he->hists->stats.total_period;
+	u64 pair_total = pair->hists->stats.total_period;
+
+	if (symbol_conf.filter_relative) {
+		he_total = he->hists->stats.total_non_filtered_period;
+		pair_total = pair->hists->stats.total_non_filtered_period;
+	}
 	return scnprintf(buf, size,
 			 "(%" PRIu64 " * 100 / %" PRIu64 ") - "
 			 "(%" PRIu64 " * 100 / %" PRIu64 ")",
-			  pair->stat.period, pair->hists->stats.total_period,
-			  he->stat.period, he->hists->stats.total_period);
+			 pair->stat.period, pair_total,
+			 he->stat.period, he_total);
 }
 
 static int formula_ratio(struct hist_entry *he, struct hist_entry *pair,
@@ -327,15 +335,16 @@
 		return -1;
 	}
 
-	if (al.filtered)
-		return 0;
-
 	if (hists__add_entry(&evsel->hists, &al, sample->period,
 			     sample->weight, sample->transaction)) {
 		pr_warning("problem incrementing symbol period, skipping event\n");
 		return -1;
 	}
 
+	if (al.filtered == 0) {
+		evsel->hists.stats.total_non_filtered_period += sample->period;
+		evsel->hists.nr_non_filtered_entries++;
+	}
 	evsel->hists.stats.total_period += sample->period;
 	return 0;
 }
@@ -565,7 +574,9 @@
 	next = rb_first(root);
 
 	hists->nr_entries = 0;
+	hists->nr_non_filtered_entries = 0;
 	hists->stats.total_period = 0;
+	hists->stats.total_non_filtered_period = 0;
 	hists__reset_col_len(hists);
 
 	while (next != NULL) {
@@ -732,13 +743,16 @@
 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
 		    "Look for files with symbols relative to this directory"),
 	OPT_UINTEGER('o', "order", &sort_compute, "Specify compute sorting."),
+	OPT_CALLBACK(0, "percentage", NULL, "relative|absolute",
+		     "How to display percentage of filtered entries", parse_filter_percentage),
 	OPT_END()
 };
 
 static double baseline_percent(struct hist_entry *he)
 {
-	struct hists *hists = he->hists;
-	return 100.0 * he->stat.period / hists->stats.total_period;
+	u64 total = hists__total_period(he->hists);
+
+	return 100.0 * he->stat.period / total;
 }
 
 static int hpp__color_baseline(struct perf_hpp_fmt *fmt,