perf cpumap: Use existing allocator to avoid using malloc

Use the existing allocator for perf_cpu_map to avoid use of raw malloc.
This could cause an issue in later commits where the size of
perf_cpu_map is changed.

No functional changes.

Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: John Garry <john.garry@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20201126141328.6509-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index dc5c5e6..20e3a75 100644 (file)
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -132,15 +132,16 @@ int cpu_map__build_map(struct perf_cpu_map *cpus, struct perf_cpu_map **res,
                       int (*f)(struct perf_cpu_map *map, int cpu, void *data),
                       void *data)
 {
-       struct perf_cpu_map *c;
        int nr = cpus->nr;
+       struct perf_cpu_map *c = perf_cpu_map__empty_new(nr);
        int cpu, s1, s2;
 
-       /* allocate as much as possible */
-       c = calloc(1, sizeof(*c) + nr * sizeof(int));
        if (!c)
                return -1;
 
+       /* Reset size as it may only be partially filled */
+       c->nr = 0;
+
        for (cpu = 0; cpu < nr; cpu++) {
                s1 = f(cpus, cpu, data);
                for (s2 = 0; s2 < c->nr; s2++) {
@@ -155,7 +156,6 @@ int cpu_map__build_map(struct perf_cpu_map *cpus, struct perf_cpu_map **res,
        /* ensure we process id in increasing order */
        qsort(c->map, c->nr, sizeof(int), cmp_ids);
 
-       refcount_set(&c->refcnt, 1);
        *res = c;
        return 0;
 }