perf cpumap: Add equal function

Equality is a useful property to compare after merging and
intersecting maps.

Reviewed-by: Kan Liang <[e-mail]>
Signed-off-by: Ian Rogers <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ali Saidi <[e-mail]>
Cc: Athira Rajeev <[e-mail]>
Cc: Dmitrii Dolgov <[e-mail]>
Cc: Huacai Chen <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jing Zhang <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Kajol Jain <[e-mail]>
Cc: Kang Minchul <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Madhavan Srinivasan <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Mike Leach <[e-mail]>
Cc: Ming Wang <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Sandipan Das <[e-mail]>
Cc: Sean Christopherson <[e-mail]>
Cc: Suzuki Poulouse <[e-mail]>
Cc: Thomas Richter <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Xing Zhengjun <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/lib/perf/cpumap.c

···
 	return perf_cpu_map__idx(cpus, cpu) != -1;
 }
 
+bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_map *rhs)
+{
+	int nr;
+
+	if (lhs == rhs)
+		return true;
+
+	if (!lhs || !rhs)
+		return false;
+
+	nr = __perf_cpu_map__nr(lhs);
+	if (nr != __perf_cpu_map__nr(rhs))
+		return false;
+
+	for (int idx = 0; idx < nr; idx++) {
+		if (__perf_cpu_map__cpu(lhs, idx).cpu != __perf_cpu_map__cpu(rhs, idx).cpu)
+			return false;
+	}
+	return true;
+}
+
 struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map)
 {
 	struct perf_cpu result = {

tools/lib/perf/include/perf/cpumap.h

···
 LIBPERF_API bool perf_cpu_map__empty(const struct perf_cpu_map *map);
 LIBPERF_API struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map);
 LIBPERF_API bool perf_cpu_map__has(const struct perf_cpu_map *map, struct perf_cpu cpu);
+LIBPERF_API bool perf_cpu_map__equal(const struct perf_cpu_map *lhs,
+				     const struct perf_cpu_map *rhs);
 
 #define perf_cpu_map__for_each_cpu(cpu, idx, cpus)		\
 	for ((idx) = 0, (cpu) = perf_cpu_map__cpu(cpus, idx);	\

tools/perf/tests/cpumap.c

···
 	return ret;
 }
 
+static int test__cpu_map_equal(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
+{
+	struct perf_cpu_map *any = perf_cpu_map__dummy_new();
+	struct perf_cpu_map *one = perf_cpu_map__new("1");
+	struct perf_cpu_map *two = perf_cpu_map__new("2");
+	struct perf_cpu_map *empty = perf_cpu_map__intersect(one, two);
+	struct perf_cpu_map *pair = perf_cpu_map__new("1-2");
+	struct perf_cpu_map *tmp;
+	struct perf_cpu_map *maps[] = {empty, any, one, two, pair};
+
+	for (size_t i = 0; i < ARRAY_SIZE(maps); i++) {
+		/* Maps equal themself. */
+		TEST_ASSERT_VAL("equal", perf_cpu_map__equal(maps[i], maps[i]));
+		for (size_t j = 0; j < ARRAY_SIZE(maps); j++) {
+			/* Maps dont't equal each other. */
+			if (i == j)
+				continue;
+			TEST_ASSERT_VAL("not equal", !perf_cpu_map__equal(maps[i], maps[j]));
+		}
+	}
+
+	/* Maps equal made maps. */
+	tmp = perf_cpu_map__merge(perf_cpu_map__get(one), two);
+	TEST_ASSERT_VAL("pair", perf_cpu_map__equal(pair, tmp));
+	perf_cpu_map__put(tmp);
+
+	tmp = perf_cpu_map__intersect(pair, one);
+	TEST_ASSERT_VAL("one", perf_cpu_map__equal(one, tmp));
+	perf_cpu_map__put(tmp);
+
+	for (size_t i = 0; i < ARRAY_SIZE(maps); i++)
+		perf_cpu_map__put(maps[i]);
+
+	return TEST_OK;
+}
+
 static struct test_case tests__cpu_map[] = {
 	TEST_CASE("Synthesize cpu map", cpu_map_synthesize),
 	TEST_CASE("Print cpu map", cpu_map_print),
 	TEST_CASE("Merge cpu map", cpu_map_merge),
 	TEST_CASE("Intersect cpu map", cpu_map_intersect),
+	TEST_CASE("Equal cpu map", cpu_map_equal),
 	{	.name = NULL, }
 };