[PATCH v1 6/7] perf ui hist: Format group headers iteratively based on proportional visual allocations

[Ian Rogers <irogers@google.com>]

Forcefully calculate proportional visual allocations only natively for
the 'Total' merge target header instead of uniformly ballooning array
spacings. Unpack strings directly into the primary column width fn.

Signed-off-by: Ian Rogers <irogers@google.com>
Assisted-by: Antigravity:gemini-3.1-pro
---
 tools/perf/ui/hist.c     | 86 ++++++++++++++++++++++++++++++++--------
 tools/perf/util/evlist.c |  9 +++--
 tools/perf/util/hist.h   |  8 +++-
 3 files changed, 82 insertions(+), 21 deletions(-)

diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index 09f0baa808e0..02c188100b09 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -57,8 +57,9 @@ struct hpp_fmt_value {
 };
 
 static int __hpp__fmt(struct perf_hpp *hpp, struct hist_entry *he,
-		      hpp_field_fn get_field, const char *fmt, int len,
-		      hpp_snprint_fn print_fn, enum perf_hpp_fmt_type fmtype)
+		      hpp_field_fn get_field, const char *fmtstr, int len,
+		      hpp_snprint_fn print_fn, enum perf_hpp_fmt_type fmtype,
+		      struct perf_hpp_fmt *fmt)
 {
 	int ret = 0;
 	struct hists *hists = he->hists;
@@ -98,14 +99,44 @@ static int __hpp__fmt(struct perf_hpp *hpp, struct hist_entry *he,
 		}
 	}
 
-	for (i = 0; i < nr_members; i++) {
-		if (symbol_conf.skip_empty &&
-		    values[i].hists->stats.nr_samples == 0)
-			continue;
+	if (he->hists->merge_entries) {
+		u64 total_val = 0;
+		u64 total_samples = 0;
+		u64 total_period = 0;
+
+		for (i = 0; i < nr_members; i++) {
+			total_val += values[i].val;
+			total_samples += values[i].samples;
+			total_period += fmtype == PERF_HPP_FMT_TYPE__PERCENT ?
+					hists__total_period(values[i].hists) :
+					hists__total_latency(values[i].hists);
+		}
+
+		if (fmtype == PERF_HPP_FMT_TYPE__PERCENT || fmtype == PERF_HPP_FMT_TYPE__LATENCY) {
+			double percent = 0.0;
+
+			if (total_period)
+				percent = 100.0 * total_val / total_period;
+			ret += hpp__call_print_fn(hpp, print_fn, fmtstr, len, percent);
+		} else if (fmtype == PERF_HPP_FMT_TYPE__AVERAGE) {
+			double avg = total_samples ? (1.0 * total_val / total_samples) : 0;
 
-		ret += __hpp__fmt_print(hpp, values[i].hists, values[i].val,
-					values[i].samples, fmt, len,
-					print_fn, fmtype);
+			ret += hpp__call_print_fn(hpp, print_fn, fmtstr, len, avg);
+		} else {
+			ret += hpp__call_print_fn(hpp, print_fn, fmtstr, len, total_val);
+		}
+	}
+
+	if (!he->hists->merge_entries || &fmt->list == he->hists->hpp_list->fields.next) {
+		for (i = 0; i < nr_members; i++) {
+			if (symbol_conf.skip_empty &&
+			    values[i].hists->stats.nr_samples == 0)
+				continue;
+
+			ret += __hpp__fmt_print(hpp, values[i].hists, values[i].val,
+							values[i].samples, fmtstr, len,
+						print_fn, fmtype);
+		}
 	}
 
 	free(values);
@@ -129,7 +160,7 @@ int hpp__fmt(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
 
 	if (symbol_conf.field_sep) {
 		return __hpp__fmt(hpp, he, get_field, fmtstr, 1,
-				  print_fn, fmtype);
+				  print_fn, fmtype, fmt);
 	}
 
 	if (fmtype == PERF_HPP_FMT_TYPE__PERCENT || fmtype == PERF_HPP_FMT_TYPE__LATENCY)
@@ -137,7 +168,7 @@ int hpp__fmt(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
 	else
 		len -= 1;
 
-	return  __hpp__fmt(hpp, he, get_field, fmtstr, len, print_fn, fmtype);
+	return  __hpp__fmt(hpp, he, get_field, fmtstr, len, print_fn, fmtype, fmt);
 }
 
 int hpp__fmt_acc(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
@@ -399,10 +430,16 @@ static int hpp__width_fn(struct perf_hpp_fmt *fmt,
 		int nr = 0;
 		struct evsel *pos;
 
-		for_each_group_evsel(pos, evsel) {
-			if (!symbol_conf.skip_empty ||
-			    evsel__hists(pos)->stats.nr_samples)
-				nr++;
+		if (hists->merge_entries && &fmt->list != hists->hpp_list->fields.next) {
+			nr = 1;
+		} else {
+			for_each_group_evsel(pos, evsel) {
+				if (!symbol_conf.skip_empty ||
+				    evsel__hists(pos)->stats.nr_samples)
+					nr++;
+			}
+			if (hists->merge_entries && &fmt->list == hists->hpp_list->fields.next)
+				nr++; /* Add 1 extra unit of width generically for the 'Total' */
 		}
 
 		len = max(len, nr * fmt->len);
@@ -421,8 +458,25 @@ static int hpp__header_fn(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
 	int len = hpp__width_fn(fmt, hpp, hists);
 	const char *hdr = "";
 
-	if (line == hists->hpp_list->nr_header_lines - 1)
+	if (line == hists->hpp_list->nr_header_lines - 1) {
 		hdr = fmt->name;
+		if (hists->merge_entries && &fmt->list == hists->hpp_list->fields.next) {
+			char buf[1024];
+			int w = 0;
+			int f_len = fmt->user_len ?: fmt->len;
+			struct evsel *pos, *evsel = hists_to_evsel(hists);
+
+			w += scnprintf(buf + w, sizeof(buf) - w, "%*.*s", f_len, f_len, fmt->name);
+			for_each_group_evsel(pos, evsel) {
+				if (symbol_conf.skip_empty &&
+			    evsel__hists(pos)->stats.nr_samples == 0)
+					continue;
+				w += scnprintf(buf + w, sizeof(buf) - w, " %*.*s",
+					       f_len - 1, f_len - 1, evsel__name(pos));
+			}
+			return scnprintf(hpp->buf, hpp->size, "%*s", len, buf);
+		}
+	}
 
 	return scnprintf(hpp->buf, hpp->size, "%*s", len, hdr);
 }
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 431759e05e26..4c928ef5c985 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -324,10 +324,13 @@ void evlist__merge_hybrid(struct evlist *evlist, bool refresh_hists)
 	evlist__for_each_entry(evlist, pos) {
 		if (evsel__is_dummy_event(pos))
 			continue;
+
 		if (pos->core.leader == &pos->core && pos->core.nr_members > 1) {
 			evsel__hists(pos)->merge_entries = true;
 			symbol_conf.event_group = true;
 			symbol_conf.hybrid_merge = true;
+			if (!pos->group_name)
+				pos->group_name = strdup("Merged hybrid events");
 		}
 	}
 
@@ -345,12 +348,10 @@ void evlist__merge_hybrid(struct evlist *evlist, bool refresh_hists)
 		}
 	}
 
-	/* Now that links are formed, safely resort the active tree so the UI renders accurately */
+	/* Resort the output dynamically since group parsing bypassed this before */
 	if (symbol_conf.event_group) {
 		evlist__for_each_entry(evlist, pos) {
-			if (evsel__is_dummy_event(pos) || !evsel__is_group_leader(pos))
-				continue;
-			if (pos->core.nr_members > 1)
+			if (pos->core.leader == &pos->core && pos->core.nr_members > 1)
 				hists__output_resort(evsel__hists(pos), NULL);
 		}
 	}
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 6cb7059e8405..5a0cfa8ea264 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -339,7 +339,13 @@ static inline struct hist_entry *hist_entry__next_pair(struct hist_entry *he)
 static inline void hist_entry__add_pair(struct hist_entry *pair,
 					struct hist_entry *he)
 {
-	list_add_tail(&pair->pairs.node, &he->pairs.head);
+	struct list_head *pos;
+
+	list_for_each(pos, &he->pairs.head) {
+		if (pos == &pair->pairs.node)
+			return; /* Already paired */
+	}
+	list_move_tail(&pair->pairs.node, &he->pairs.head);
 }
 
 struct hist_entry *hists__add_entry(struct hists *hists,
-- 
2.55.0.766.g2966f0265a-goog