linux-kernel - [PATCH v6 17/47] perf maps: Do simple merge if given map doesn't overlap

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Date:   Wed,  6 Dec 2023 17:16:51 -0800
From:   Ian Rogers <irogers@...gle.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Ian Rogers <irogers@...gle.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Nick Terrell <terrelln@...com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kajol Jain <kjain@...ux.ibm.com>,
        Athira Rajeev <atrajeev@...ux.vnet.ibm.com>,
        Huacai Chen <chenhuacai@...nel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Vincent Whitchurch <vincent.whitchurch@...s.com>,
        "Steinar H. Gunderson" <sesse@...gle.com>,
        Liam Howlett <liam.howlett@...cle.com>,
        Miguel Ojeda <ojeda@...nel.org>,
        Colin Ian King <colin.i.king@...il.com>,
        Dmitrii Dolgov <9erthalion6@...il.com>,
        Yang Jihong <yangjihong1@...wei.com>,
        Ming Wang <wangming01@...ngson.cn>,
        James Clark <james.clark@....com>,
        K Prateek Nayak <kprateek.nayak@....com>,
        Sean Christopherson <seanjc@...gle.com>,
        Leo Yan <leo.yan@...aro.org>,
        Ravi Bangoria <ravi.bangoria@....com>,
        German Gomez <german.gomez@....com>,
        Changbin Du <changbin.du@...wei.com>,
        Paolo Bonzini <pbonzini@...hat.com>, Li Dong <lidong@...o.com>,
        Sandipan Das <sandipan.das@....com>,
        liuwenyu <liuwenyu7@...wei.com>, linux-kernel@...r.kernel.org,
        linux-perf-users@...r.kernel.org,
        Guilherme Amadio <amadio@...too.org>
Subject: [PATCH v6 17/47] perf maps: Do simple merge if given map doesn't overlap

Simplify merge in for the simple case of a non-overlapping map.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/util/maps.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
index 94a97923527d..f305a4834cf0 100644
--- a/tools/perf/util/maps.c
+++ b/tools/perf/util/maps.c
@@ -697,9 +697,20 @@ void maps__fixup_end(struct maps *maps)
 int maps__merge_in(struct maps *kmaps, struct map *new_map)
 {
 	struct map_rb_node *rb_node;
+	struct rb_node *first;
+	bool overlaps;
 	LIST_HEAD(merged);
 	int err = 0;
 
+	down_read(maps__lock(kmaps));
+	first = first_ending_after(kmaps, new_map);
+	rb_node = first ? rb_entry(first, struct map_rb_node, rb_node) : NULL;
+	overlaps = rb_node && map__start(rb_node->map) < map__end(new_map);
+	up_read(maps__lock(kmaps));
+
+	if (!overlaps)
+		return maps__insert(kmaps, new_map);
+
 	maps__for_each_entry(kmaps, rb_node) {
 		struct map *old_map = rb_node->map;
 
-- 
2.43.0.rc2.451.g8631bc7472-goog