[PATCH v3 6/7] perf util: Report hot streams

[Jin Yao]

We show the streams separately. They are divided into different sections.

1. "Matched hot chains between old perf data and new perf data"

2. "Hot chains in old perf data but source line changed in new perf data"

3. "Hot chains in old perf data only"

4. "Hot chains in new perf data only".

For each stream, we report the cycles and hot percent (hits%).

For example,

     cycles: 2, hits: 4.08%
 --------------------------
              main div.c:42
      compute_flag div.c:28

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/util/callchain.c | 155 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/callchain.h |   3 +
 2 files changed, 158 insertions(+)

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index b0c8757c2dcf..84fe8e418532 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1777,6 +1777,9 @@ static bool chain_srclist_match(struct srclist *src_list, const char *srcline_a,
 	struct src_node *node;
 	struct line_pair *lp;
 
+	if (!srcline_a || !srcline_b)
+		return false;
+
 	if (sscanf(srcline_a, "%[^:]:%d", file_a, &line_a) != 2)
 		return false;
 
@@ -1817,6 +1820,10 @@ static bool chain_match(struct callchain_list *base_chain,
 
 	*src_changed = false;
 
+	/*
+	 * Check sourceline first. If not matched,
+	 * fallback to symbol match and address match.
+	 */
 	if (src_list && chain_srclist_match(src_list, pair_chain->srcline,
 					    base_chain->srcline, &src_found,
 					    src_changed)) {
@@ -1939,3 +1946,151 @@ void callchain_match_streams(struct callchain_streams *cs_base,
 	if (src_list)
 		srclist__dump(src_list);
 }
+
+static s64 callchain_avg_cycles(struct callchain_node *cnode)
+{
+	struct callchain_list *chain;
+	s64 cycles = 0;
+
+	list_for_each_entry(chain, &cnode->val, list) {
+		if (chain->srcline && chain->branch_count)
+			cycles += chain->cycles_count / chain->branch_count;
+	}
+
+	return cycles;
+}
+
+static void print_callchain_pair(struct stream_node *base_node, int idx,
+				 struct callchain_streams *cs_base,
+				 struct callchain_streams *cs_pair)
+{
+	struct callchain_node *base_cnode = base_node->cnode;
+	struct callchain_node *pair_cnode = base_node->pair_cnode;
+	struct callchain_list *base_chain, *pair_chain;
+	char buf1[512], buf2[512], cbuf1[256], cbuf2[256];
+	char *s1, *s2;
+	double pct;
+
+	printf("\nhot chain pair %d:\n", idx);
+
+	pct = (double)base_cnode->hit / (double)cs_base->chain_hits;
+	scnprintf(buf1, sizeof(buf1), "cycles: %ld, hits: %.2f%%",
+		  callchain_avg_cycles(base_cnode), pct * 100.0);
+
+	pct = (double)pair_cnode->hit / (double)cs_pair->chain_hits;
+	scnprintf(buf2, sizeof(buf2), "cycles: %ld, hits: %.2f%%",
+		  callchain_avg_cycles(pair_cnode), pct * 100.0);
+
+	printf("%35s\t%35s\n", buf1, buf2);
+
+	printf("%35s\t%35s\n",
+	       "---------------------------",
+	       "--------------------------");
+
+	pair_chain = list_first_entry(&pair_cnode->val,
+				      struct callchain_list,
+				      list);
+
+	list_for_each_entry(base_chain, &base_cnode->val, list) {
+		if (&pair_chain->list == &pair_cnode->val)
+			return;
+
+		s1 = callchain_list__sym_name(base_chain, cbuf1, sizeof(cbuf1),
+					      false);
+		s2 = callchain_list__sym_name(pair_chain, cbuf2, sizeof(cbuf2),
+					      false);
+
+		if (!pair_chain->src_changed)
+			scnprintf(buf1, sizeof(buf1), "%35s\t%35s", s1, s2);
+		else
+			scnprintf(buf1, sizeof(buf1), "%35s\t%35s*", s1, s2);
+
+		printf("%s\n", buf1);
+		pair_chain = list_next_entry(pair_chain, list);
+	}
+}
+
+static void print_stream_callchain(struct stream_node *node, int idx,
+				   struct callchain_streams *cs, bool pair)
+{
+	struct callchain_node *cnode = node->cnode;
+	struct callchain_list *chain;
+	char buf[512], cbuf[256], *s;
+	double pct;
+
+	printf("\nhot chain %d:\n", idx);
+
+	pct = (double)cnode->hit / (double)cs->chain_hits;
+	scnprintf(buf, sizeof(buf), "cycles: %ld, hits: %.2f%%",
+		  callchain_avg_cycles(cnode), pct * 100.0);
+
+	if (pair) {
+		printf("%35s\t%35s\n", "", buf);
+		printf("%35s\t%35s\n",
+		       "", "--------------------------");
+	} else {
+		printf("%35s\n", buf);
+		printf("%35s\n", "--------------------------");
+	}
+
+	list_for_each_entry(chain, &cnode->val, list) {
+		s = callchain_list__sym_name(chain, cbuf, sizeof(cbuf), false);
+
+		if (pair)
+			scnprintf(buf, sizeof(buf), "%35s\t%35s", "", s);
+		else
+			scnprintf(buf, sizeof(buf), "%35s", s);
+
+		printf("%s\n", buf);
+	}
+}
+
+void callchain_stream_report(struct callchain_streams *cs_base,
+			     struct callchain_streams *cs_pair)
+{
+	struct stream_node *base_node;
+	int i, idx = 0;
+
+	printf("[ Matched hot chains between old perf data and new perf data ]\n");
+	for (i = 0; i < cs_base->nr_streams; i++) {
+		base_node = &cs_base->streams[i];
+		if (base_node->pair_cnode) {
+			if (!base_node->src_changed) {
+				print_callchain_pair(base_node, ++idx,
+						     cs_base, cs_pair);
+			}
+		}
+	}
+
+	idx = 0;
+	printf("\n[ Hot chains in old perf data but source line changed (*) in new perf data ]\n");
+	for (i = 0; i < cs_base->nr_streams; i++) {
+		base_node = &cs_base->streams[i];
+		if (base_node->pair_cnode) {
+			if (base_node->src_changed) {
+				print_callchain_pair(base_node, ++idx,
+						     cs_base, cs_pair);
+			}
+		}
+	}
+
+	idx = 0;
+	printf("\n[ Hot chains in old perf data only ]\n");
+	for (i = 0; i < cs_base->nr_streams; i++) {
+		base_node = &cs_base->streams[i];
+		if (!base_node->pair_cnode) {
+			print_stream_callchain(base_node, ++idx,
+					       cs_base, false);
+		}
+	}
+
+	idx = 0;
+	printf("\n[ Hot chains in new perf data only ]\n");
+	for (i = 0; i < cs_pair->nr_streams; i++) {
+		base_node = &cs_pair->streams[i];
+		if (!base_node->pair_cnode) {
+			print_stream_callchain(base_node, ++idx,
+					       cs_pair, true);
+		}
+	}
+}
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index a9b20b785dc7..8835d63a212f 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -326,4 +326,7 @@ void callchain_match_streams(struct callchain_streams *cs_base,
 			     struct callchain_streams *cs_pair,
 			     struct srclist *src_list);
 
+void callchain_stream_report(struct callchain_streams *cs_base,
+			     struct callchain_streams *cs_pair);
+
 #endif	/* __PERF_CALLCHAIN_H */
-- 
2.17.1