libperf cpumap: Refactor perf_cpu_map__merge()

The perf_cpu_map__merge() function has two arguments, 'orig' and
'other'.  The function definition might cause confusion as it could give
the impression that the CPU maps in the two arguments are copied into a
new allocated structure, which is then returned as the result.

The purpose of the function is to merge the CPU map 'other' into the CPU
map 'orig'.  This commit changes the 'orig' argument to a pointer to
pointer, so the new result will be updated into 'orig'.

The return value is changed to an int type, as an error number or 0 for
success.

Update callers and tests for the new function definition.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241107125308.41226-2-leo.yan@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/tools/perf/tests/cpumap.c b/tools/perf/tests/cpumap.c
index 2f0168b2a5a9..7f189d57232f 100644
--- a/tools/perf/tests/cpumap.c
+++ b/tools/perf/tests/cpumap.c
@@ -160,14 +160,14 @@ static int test__cpu_map_merge(struct test_suite *test __maybe_unused, int subte
 {
 	struct perf_cpu_map *a = perf_cpu_map__new("4,2,1");
 	struct perf_cpu_map *b = perf_cpu_map__new("4,5,7");
-	struct perf_cpu_map *c = perf_cpu_map__merge(a, b);
 	char buf[100];
 
-	TEST_ASSERT_VAL("failed to merge map: bad nr", perf_cpu_map__nr(c) == 5);
-	cpu_map__snprint(c, buf, sizeof(buf));
+	perf_cpu_map__merge(&a, b);
+	TEST_ASSERT_VAL("failed to merge map: bad nr", perf_cpu_map__nr(a) == 5);
+	cpu_map__snprint(a, buf, sizeof(buf));
 	TEST_ASSERT_VAL("failed to merge map: bad result", !strcmp(buf, "1-2,4-5,7"));
 	perf_cpu_map__put(b);
-	perf_cpu_map__put(c);
+	perf_cpu_map__put(a);
 	return 0;
 }
 
@@ -233,9 +233,8 @@ static int test__cpu_map_equal(struct test_suite *test __maybe_unused, int subte
 	}
 
 	/* 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);
+	perf_cpu_map__merge(&two, one);
+	TEST_ASSERT_VAL("pair", perf_cpu_map__equal(pair, two));
 
 	tmp = perf_cpu_map__intersect(pair, one);
 	TEST_ASSERT_VAL("one", perf_cpu_map__equal(one, tmp));