Re: [PATCH v1] libperf cpumap: Make index and nr types unsigned

[Ian Rogers]

On Fri, Mar 27, 2026 at 1:55 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> On Thu, Mar 19, 2026 at 01:18:43AM -0700, Ian Rogers wrote:
> > The index into the cpumap array and the number of entries within the
> > array can never be negative, so let's make them unsigned. This is
> > prompted by reports that gcc 13 with -O6 is giving a
> > alloc-size-larger-than errors. The change makes the cpumap changes and
> > then updates the declaration of index variables throughout perf and
> > libperf to be unsigned. The two things are hard to separate as
> > compiler warnings about mixing signed and unsigned types breaks the
> > build.
> >
> > Reported-by: Chingbin Li <liqb365@xxxxxxx>
> > Closes: https://lore.kernel.org/lkml/20260212025127.841090-1-liqb365@xxxxxxx/
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/lib/perf/cpumap.c                       | 49 +++++++++----------
> >  tools/lib/perf/evsel.c                        | 10 ++--
> >  tools/lib/perf/include/internal/cpumap.h      |  6 +--
> >  tools/lib/perf/include/perf/cpumap.h          |  4 +-
> >  tools/perf/arch/arm/util/cs-etm.c             |  7 +--
> >  tools/perf/arch/arm64/util/arm-spe.c          |  3 +-
> >  tools/perf/arch/arm64/util/header.c           |  2 +-
> >  tools/perf/arch/x86/util/pmu.c                |  3 +-
> >  tools/perf/builtin-c2c.c                      |  6 +--
> >  tools/perf/builtin-record.c                   |  2 +-
> >  tools/perf/builtin-script.c                   |  5 +-
> >  tools/perf/builtin-stat.c                     |  2 +-
> >  tools/perf/tests/bitmap.c                     |  2 +-
> >  tools/perf/tests/cpumap.c                     |  6 ++-
> >  tools/perf/tests/mem2node.c                   |  2 +-
> >  tools/perf/tests/openat-syscall-all-cpus.c    |  3 +-
> >  tools/perf/tests/topology.c                   |  4 +-
> >  tools/perf/util/affinity.c                    |  2 +-
> >  tools/perf/util/bpf_counter.c                 | 24 ++++-----
> >  tools/perf/util/bpf_counter_cgroup.c          |  8 +--
> >  tools/perf/util/bpf_kwork.c                   |  3 +-
> >  tools/perf/util/bpf_kwork_top.c               |  3 +-
> >  tools/perf/util/bpf_off_cpu.c                 |  2 +-
> >  tools/perf/util/bpf_trace_augment.c           |  2 +-
> >  tools/perf/util/cpumap.c                      | 10 ++--
> >  tools/perf/util/cputopo.c                     |  2 +-
> >  tools/perf/util/env.c                         |  2 +-
> >  .../scripting-engines/trace-event-python.c    |  2 +-
> >  tools/perf/util/session.c                     |  3 +-
> >  tools/perf/util/stat-display.c                |  4 +-
> >  tools/perf/util/stat.c                        |  8 +--
> >  tools/perf/util/svghelper.c                   |  3 +-
> >  tools/perf/util/symbol.c                      |  3 +-
> >  tools/perf/util/synthetic-events.c            |  2 +-
> >  34 files changed, 108 insertions(+), 91 deletions(-)
> >
> > diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c
> > index 4160e7d2e120..b987b7c7cee2 100644
> > --- a/tools/lib/perf/cpumap.c
> > +++ b/tools/lib/perf/cpumap.c
> > @@ -15,12 +15,12 @@
> >
> >  #define MAX_NR_CPUS 4096
> >
> > -void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus)
> > +void perf_cpu_map__set_nr(struct perf_cpu_map *map, unsigned int nr_cpus)
> >  {
> >       RC_CHK_ACCESS(map)->nr = nr_cpus;
> >  }
> >
> > -struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
> > +struct perf_cpu_map *perf_cpu_map__alloc(unsigned int nr_cpus)
> >  {
> >       RC_STRUCT(perf_cpu_map) *cpus;
> >       struct perf_cpu_map *result;
> > @@ -78,7 +78,7 @@ void perf_cpu_map__put(struct perf_cpu_map *map)
> >  static struct perf_cpu_map *cpu_map__new_sysconf(void)
> >  {
> >       struct perf_cpu_map *cpus;
> > -     int nr_cpus, nr_cpus_conf;
> > +     long nr_cpus, nr_cpus_conf;
>
> Shouldn't it be unsigned int?

The value from sysconf is a long and we need to check for negative
values as an error condition.

> >
> >       nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
> >       if (nr_cpus < 0)
> > @@ -86,15 +86,13 @@ static struct perf_cpu_map *cpu_map__new_sysconf(void)
> >
> >       nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF);
> >       if (nr_cpus != nr_cpus_conf) {
> > -             pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.",
> > +             pr_warning("Number of online CPUs (%ld) differs from the number configured (%ld) the CPU map will only cover the first %ld CPUs.",
> >                       nr_cpus, nr_cpus_conf, nr_cpus);
> >       }
> >
> >       cpus = perf_cpu_map__alloc(nr_cpus);
> >       if (cpus != NULL) {
> > -             int i;
> > -
> > -             for (i = 0; i < nr_cpus; ++i)
> > +             for (unsigned int i = 0; i < nr_cpus; ++i)
> >                       RC_CHK_ACCESS(cpus)->map[i].cpu = i;
>
> I got this:
>
> cpumap.c: In function 'cpu_map__new_sysconf':
> cpumap.c:95:44: error: comparison of integer expressions of different signedness: 'unsigned int' and 'long int' [-Werror=sign-compare]
>    95 |                 for (unsigned int i = 0; i < nr_cpus; ++i)
>       |                                            ^

Thanks, I'll take a look.

Ian

> Thanks,
> Namhyung
>
> >       }
> >
> > @@ -132,23 +130,23 @@ static int cmp_cpu(const void *a, const void *b)
> >       return cpu_a->cpu - cpu_b->cpu;
> >  }
> >
> > -static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
> > +static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, unsigned int idx)
> >  {
> >       return RC_CHK_ACCESS(cpus)->map[idx];
> >  }
> >
> > -static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu *tmp_cpus)
> > +static struct perf_cpu_map *cpu_map__trim_new(unsigned int nr_cpus, const struct perf_cpu *tmp_cpus)
> >  {
> >       size_t payload_size = nr_cpus * sizeof(struct perf_cpu);
> >       struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr_cpus);
> > -     int i, j;
> >
> >       if (cpus != NULL) {
> > +             unsigned int j = 0;
> > +
> >               memcpy(RC_CHK_ACCESS(cpus)->map, tmp_cpus, payload_size);
> >               qsort(RC_CHK_ACCESS(cpus)->map, nr_cpus, sizeof(struct perf_cpu), cmp_cpu);
> >               /* Remove dups */
> > -             j = 0;
> > -             for (i = 0; i < nr_cpus; i++) {
> > +             for (unsigned int i = 0; i < nr_cpus; i++) {
> >                       if (i == 0 ||
> >                           __perf_cpu_map__cpu(cpus, i).cpu !=
> >                           __perf_cpu_map__cpu(cpus, i - 1).cpu) {
> > @@ -167,9 +165,8 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
> >       struct perf_cpu_map *cpus = NULL;
> >       unsigned long start_cpu, end_cpu = 0;
> >       char *p = NULL;
> > -     int i, nr_cpus = 0;
> > +     unsigned int nr_cpus = 0, max_entries = 0;
> >       struct perf_cpu *tmp_cpus = NULL, *tmp;
> > -     int max_entries = 0;
> >
> >       if (!cpu_list)
> >               return perf_cpu_map__new_online_cpus();
> > @@ -208,9 +205,10 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
> >
> >               for (; start_cpu <= end_cpu; start_cpu++) {
> >                       /* check for duplicates */
> > -                     for (i = 0; i < nr_cpus; i++)
> > +                     for (unsigned int i = 0; i < nr_cpus; i++) {
> >                               if (tmp_cpus[i].cpu == (int16_t)start_cpu)
> >                                       goto invalid;
> > +                     }
> >
> >                       if (nr_cpus == max_entries) {
> >                               max_entries += max(end_cpu - start_cpu + 1, 16UL);
> > @@ -252,12 +250,12 @@ struct perf_cpu_map *perf_cpu_map__new_int(int cpu)
> >       return cpus;
> >  }
> >
> > -static int __perf_cpu_map__nr(const struct perf_cpu_map *cpus)
> > +static unsigned int __perf_cpu_map__nr(const struct perf_cpu_map *cpus)
> >  {
> >       return RC_CHK_ACCESS(cpus)->nr;
> >  }
> >
> > -struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
> > +struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, unsigned int idx)
> >  {
> >       struct perf_cpu result = {
> >               .cpu = -1
> > @@ -269,7 +267,7 @@ struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
> >       return result;
> >  }
> >
> > -int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
> > +unsigned int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
> >  {
> >       return cpus ? __perf_cpu_map__nr(cpus) : 1;
> >  }
> > @@ -294,7 +292,7 @@ bool perf_cpu_map__is_empty(const struct perf_cpu_map *map)
> >
> >  int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
> >  {
> > -     int low, high;
> > +     unsigned int low, high;
> >
> >       if (!cpus)
> >               return -1;
> > @@ -324,7 +322,7 @@ bool perf_cpu_map__has(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
> >
> >  bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_map *rhs)
> >  {
> > -     int nr;
> > +     unsigned int nr;
> >
> >       if (lhs == rhs)
> >               return true;
> > @@ -336,7 +334,7 @@ bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_m
> >       if (nr != __perf_cpu_map__nr(rhs))
> >               return false;
> >
> > -     for (int idx = 0; idx < nr; idx++) {
> > +     for (unsigned int idx = 0; idx < nr; idx++) {
> >               if (__perf_cpu_map__cpu(lhs, idx).cpu != __perf_cpu_map__cpu(rhs, idx).cpu)
> >                       return false;
> >       }
> > @@ -353,7 +351,7 @@ struct perf_cpu perf_cpu_map__min(const struct perf_cpu_map *map)
> >       struct perf_cpu cpu, result = {
> >               .cpu = -1
> >       };
> > -     int idx;
> > +     unsigned int idx;
> >
> >       perf_cpu_map__for_each_cpu_skip_any(cpu, idx, map) {
> >               result = cpu;
> > @@ -384,7 +382,7 @@ bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu
> >       if (!a || __perf_cpu_map__nr(b) > __perf_cpu_map__nr(a))
> >               return false;
> >
> > -     for (int i = 0, j = 0; i < __perf_cpu_map__nr(a); i++) {
> > +     for (unsigned int i = 0, j = 0; i < __perf_cpu_map__nr(a); i++) {
> >               if (__perf_cpu_map__cpu(a, i).cpu > __perf_cpu_map__cpu(b, j).cpu)
> >                       return false;
> >               if (__perf_cpu_map__cpu(a, i).cpu == __perf_cpu_map__cpu(b, j).cpu) {
> > @@ -410,8 +408,7 @@ bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu
> >  int perf_cpu_map__merge(struct perf_cpu_map **orig, struct perf_cpu_map *other)
> >  {
> >       struct perf_cpu *tmp_cpus;
> > -     int tmp_len;
> > -     int i, j, k;
> > +     unsigned int tmp_len, i, j, k;
> >       struct perf_cpu_map *merged;
> >
> >       if (perf_cpu_map__is_subset(*orig, other))
> > @@ -455,7 +452,7 @@ int perf_cpu_map__merge(struct perf_cpu_map **orig, struct perf_cpu_map *other)
> >  struct perf_cpu_map *perf_cpu_map__intersect(struct perf_cpu_map *orig,
> >                                            struct perf_cpu_map *other)
> >  {
> > -     int i, j, k;
> > +     unsigned int i, j, k;
> >       struct perf_cpu_map *merged;
> >
> >       if (perf_cpu_map__is_subset(other, orig))
> > diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
> > index 13a307fc75ae..f747c0bc692d 100644
> > --- a/tools/lib/perf/evsel.c
> > +++ b/tools/lib/perf/evsel.c
> > @@ -127,7 +127,8 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
> >                    struct perf_thread_map *threads)
> >  {
> >       struct perf_cpu cpu;
> > -     int idx, thread, err = 0;
> > +     unsigned int idx;
> > +     int thread, err = 0;
> >
> >       if (cpus == NULL) {
> >               static struct perf_cpu_map *empty_cpu_map;
> > @@ -460,7 +461,7 @@ int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu_map_idx)
> >  int perf_evsel__enable_thread(struct perf_evsel *evsel, int thread)
> >  {
> >       struct perf_cpu cpu __maybe_unused;
> > -     int idx;
> > +     unsigned int idx;
> >       int err;
> >
> >       perf_cpu_map__for_each_cpu(cpu, idx, evsel->cpus) {
> > @@ -499,12 +500,13 @@ int perf_evsel__disable(struct perf_evsel *evsel)
> >
> >  int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
> >  {
> > -     int err = 0, i;
> > +     int err = 0;
> >
> > -     for (i = 0; i < perf_cpu_map__nr(evsel->cpus) && !err; i++)
> > +     for (unsigned int i = 0; i < perf_cpu_map__nr(evsel->cpus) && !err; i++) {
> >               err = perf_evsel__run_ioctl(evsel,
> >                                    PERF_EVENT_IOC_SET_FILTER,
> >                                    (void *)filter, i);
> > +     }
> >       return err;
> >  }
> >
> > diff --git a/tools/lib/perf/include/internal/cpumap.h b/tools/lib/perf/include/internal/cpumap.h
> > index e2be2d17c32b..c19678188b17 100644
> > --- a/tools/lib/perf/include/internal/cpumap.h
> > +++ b/tools/lib/perf/include/internal/cpumap.h
> > @@ -16,16 +16,16 @@
> >  DECLARE_RC_STRUCT(perf_cpu_map) {
> >       refcount_t      refcnt;
> >       /** Length of the map array. */
> > -     int             nr;
> > +     unsigned int    nr;
> >       /** The CPU values. */
> >       struct perf_cpu map[];
> >  };
> >
> > -struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus);
> > +struct perf_cpu_map *perf_cpu_map__alloc(unsigned int nr_cpus);
> >  int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu);
> >  bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b);
> >
> > -void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus);
> > +void perf_cpu_map__set_nr(struct perf_cpu_map *map, unsigned int nr_cpus);
> >
> >  static inline refcount_t *perf_cpu_map__refcnt(struct perf_cpu_map *map)
> >  {
> > diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h
> > index 58cc5c5fa47c..a1dd25db65b6 100644
> > --- a/tools/lib/perf/include/perf/cpumap.h
> > +++ b/tools/lib/perf/include/perf/cpumap.h
> > @@ -49,7 +49,7 @@ LIBPERF_API void perf_cpu_map__put(struct perf_cpu_map *map);
> >   * perf_cpu_map__cpu - get the CPU value at the given index. Returns -1 if index
> >   *                     is invalid.
> >   */
> > -LIBPERF_API struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx);
> > +LIBPERF_API struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, unsigned int idx);
> >  /**
> >   * perf_cpu_map__nr - for an empty map returns 1, as perf_cpu_map__cpu returns a
> >   *                    cpu of -1 for an invalid index, this makes an empty map
> > @@ -57,7 +57,7 @@ LIBPERF_API struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, i
> >   *                    the result is the number CPUs in the map plus one if the
> >   *                    "any CPU"/dummy value is present.
> >   */
> > -LIBPERF_API int perf_cpu_map__nr(const struct perf_cpu_map *cpus);
> > +LIBPERF_API unsigned int perf_cpu_map__nr(const struct perf_cpu_map *cpus);
> >  /**
> >   * perf_cpu_map__has_any_cpu_or_is_empty - is map either empty or has the "any CPU"/dummy value.
> >   */
> > diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
> > index dc3f4e86b075..cc880ab596fe 100644
> > --- a/tools/perf/arch/arm/util/cs-etm.c
> > +++ b/tools/perf/arch/arm/util/cs-etm.c
> > @@ -211,7 +211,8 @@ static struct perf_pmu *cs_etm_get_pmu(struct auxtrace_record *itr)
> >  static int cs_etm_validate_config(struct perf_pmu *cs_etm_pmu,
> >                                 struct evsel *evsel)
> >  {
> > -     int idx, err = 0;
> > +     unsigned int idx;
> > +     int err = 0;
> >       struct perf_cpu_map *event_cpus = evsel->evlist->core.user_requested_cpus;
> >       struct perf_cpu_map *intersect_cpus;
> >       struct perf_cpu cpu;
> > @@ -560,7 +561,7 @@ static size_t
> >  cs_etm_info_priv_size(struct auxtrace_record *itr,
> >                     struct evlist *evlist)
> >  {
> > -     int idx;
> > +     unsigned int idx;
> >       int etmv3 = 0, etmv4 = 0, ete = 0;
> >       struct perf_cpu_map *event_cpus = evlist->core.user_requested_cpus;
> >       struct perf_cpu_map *intersect_cpus;
> > @@ -797,7 +798,7 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
> >                           struct perf_record_auxtrace_info *info,
> >                           size_t priv_size)
> >  {
> > -     int i;
> > +     unsigned int i;
> >       u32 offset;
> >       u64 nr_cpu, type;
> >       struct perf_cpu_map *cpu_map;
> > diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
> > index 17ced7bbbdda..f00d72d087fc 100644
> > --- a/tools/perf/arch/arm64/util/arm-spe.c
> > +++ b/tools/perf/arch/arm64/util/arm-spe.c
> > @@ -144,7 +144,8 @@ static int arm_spe_info_fill(struct auxtrace_record *itr,
> >                            struct perf_record_auxtrace_info *auxtrace_info,
> >                            size_t priv_size)
> >  {
> > -     int i, ret;
> > +     unsigned int i;
> > +     int ret;
> >       size_t offset;
> >       struct arm_spe_recording *sper =
> >                       container_of(itr, struct arm_spe_recording, itr);
> > diff --git a/tools/perf/arch/arm64/util/header.c b/tools/perf/arch/arm64/util/header.c
> > index cbc0ba101636..95e71c4f6c78 100644
> > --- a/tools/perf/arch/arm64/util/header.c
> > +++ b/tools/perf/arch/arm64/util/header.c
> > @@ -43,7 +43,7 @@ static int _get_cpuid(char *buf, size_t sz, struct perf_cpu cpu)
> >  int get_cpuid(char *buf, size_t sz, struct perf_cpu cpu)
> >  {
> >       struct perf_cpu_map *cpus;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       if (cpu.cpu != -1)
> >               return _get_cpuid(buf, sz, cpu);
> > diff --git a/tools/perf/arch/x86/util/pmu.c b/tools/perf/arch/x86/util/pmu.c
> > index 4ea4d022c9c3..0661e0f0b02d 100644
> > --- a/tools/perf/arch/x86/util/pmu.c
> > +++ b/tools/perf/arch/x86/util/pmu.c
> > @@ -221,7 +221,8 @@ static void gnr_uncore_cha_imc_adjust_cpumask_for_snc(struct perf_pmu *pmu, bool
> >       static struct perf_cpu_map *cha_adjusted[MAX_SNCS];
> >       static struct perf_cpu_map *imc_adjusted[MAX_SNCS];
> >       struct perf_cpu_map **adjusted = cha ? cha_adjusted : imc_adjusted;
> > -     int idx, pmu_snc, cpu_adjust;
> > +     unsigned int idx;
> > +     int pmu_snc, cpu_adjust;
> >       struct perf_cpu cpu;
> >       bool alloc;
> >
> > diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
> > index d390ae4e3ec8..e60eea62c2fc 100644
> > --- a/tools/perf/builtin-c2c.c
> > +++ b/tools/perf/builtin-c2c.c
> > @@ -2310,7 +2310,6 @@ static int setup_nodes(struct perf_session *session)
> >  {
> >       struct numa_node *n;
> >       unsigned long **nodes;
> > -     int node, idx;
> >       struct perf_cpu cpu;
> >       int *cpu2node;
> >       struct perf_env *env = perf_session__env(session);
> > @@ -2335,14 +2334,15 @@ static int setup_nodes(struct perf_session *session)
> >       if (!cpu2node)
> >               return -ENOMEM;
> >
> > -     for (idx = 0; idx < c2c.cpus_cnt; idx++)
> > +     for (int idx = 0; idx < c2c.cpus_cnt; idx++)
> >               cpu2node[idx] = -1;
> >
> >       c2c.cpu2node = cpu2node;
> >
> > -     for (node = 0; node < c2c.nodes_cnt; node++) {
> > +     for (int node = 0; node < c2c.nodes_cnt; node++) {
> >               struct perf_cpu_map *map = n[node].map;
> >               unsigned long *set;
> > +             unsigned int idx;
> >
> >               set = bitmap_zalloc(c2c.cpus_cnt);
> >               if (!set)
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index 40917a0be238..63a47820fd46 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -3695,7 +3695,7 @@ struct option *record_options = __record_options;
> >  static int record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cpu_map *cpus)
> >  {
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       if (cpu_map__is_dummy(cpus))
> >               return 0;
> > diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> > index b80c406d1fc1..b005b23f9d8c 100644
> > --- a/tools/perf/builtin-script.c
> > +++ b/tools/perf/builtin-script.c
> > @@ -2572,7 +2572,6 @@ static struct scripting_ops     *scripting_ops;
> >  static void __process_stat(struct evsel *counter, u64 tstamp)
> >  {
> >       int nthreads = perf_thread_map__nr(counter->core.threads);
> > -     int idx, thread;
> >       struct perf_cpu cpu;
> >       static int header_printed;
> >
> > @@ -2582,7 +2581,9 @@ static void __process_stat(struct evsel *counter, u64 tstamp)
> >               header_printed = 1;
> >       }
> >
> > -     for (thread = 0; thread < nthreads; thread++) {
> > +     for (int thread = 0; thread < nthreads; thread++) {
> > +             unsigned int idx;
> > +
> >               perf_cpu_map__for_each_cpu(cpu, idx, evsel__cpus(counter)) {
> >                       struct perf_counts_values *counts;
> >
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index 73c2ba7e3076..46ef99f844dd 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -410,7 +410,7 @@ static int read_tool_counters(void)
> >       struct evsel *counter;
> >
> >       evlist__for_each_entry(evsel_list, counter) {
> > -             int idx;
> > +             unsigned int idx;
> >
> >               if (!evsel__is_tool(counter))
> >                       continue;
> > diff --git a/tools/perf/tests/bitmap.c b/tools/perf/tests/bitmap.c
> > index 98956e0e0765..e7adf60be721 100644
> > --- a/tools/perf/tests/bitmap.c
> > +++ b/tools/perf/tests/bitmap.c
> > @@ -16,7 +16,7 @@ static unsigned long *get_bitmap(const char *str, int nbits)
> >       bm = bitmap_zalloc(nbits);
> >
> >       if (map && bm) {
> > -             int i;
> > +             unsigned int i;
> >               struct perf_cpu cpu;
> >
> >               perf_cpu_map__for_each_cpu(cpu, i, map)
> > diff --git a/tools/perf/tests/cpumap.c b/tools/perf/tests/cpumap.c
> > index 2354246afc5a..b051dce2cd86 100644
> > --- a/tools/perf/tests/cpumap.c
> > +++ b/tools/perf/tests/cpumap.c
> > @@ -156,7 +156,8 @@ static int test__cpu_map_print(struct test_suite *test __maybe_unused, int subte
> >       return 0;
> >  }
> >
> > -static int __test__cpu_map_merge(const char *lhs, const char *rhs, int nr, const char *expected)
> > +static int __test__cpu_map_merge(const char *lhs, const char *rhs, unsigned int nr,
> > +                              const char *expected)
> >  {
> >       struct perf_cpu_map *a = perf_cpu_map__new(lhs);
> >       struct perf_cpu_map *b = perf_cpu_map__new(rhs);
> > @@ -204,7 +205,8 @@ static int test__cpu_map_merge(struct test_suite *test __maybe_unused,
> >       return ret;
> >  }
> >
> > -static int __test__cpu_map_intersect(const char *lhs, const char *rhs, int nr, const char *expected)
> > +static int __test__cpu_map_intersect(const char *lhs, const char *rhs, unsigned int nr,
> > +                                  const char *expected)
> >  {
> >       struct perf_cpu_map *a = perf_cpu_map__new(lhs);
> >       struct perf_cpu_map *b = perf_cpu_map__new(rhs);
> > diff --git a/tools/perf/tests/mem2node.c b/tools/perf/tests/mem2node.c
> > index a0e88c496107..7ce1ad7b6ce5 100644
> > --- a/tools/perf/tests/mem2node.c
> > +++ b/tools/perf/tests/mem2node.c
> > @@ -30,7 +30,7 @@ static unsigned long *get_bitmap(const char *str, int nbits)
> >
> >       if (map && bm) {
> >               struct perf_cpu cpu;
> > -             int i;
> > +             unsigned int i;
> >
> >               perf_cpu_map__for_each_cpu(cpu, i, map)
> >                       __set_bit(cpu.cpu, bm);
> > diff --git a/tools/perf/tests/openat-syscall-all-cpus.c b/tools/perf/tests/openat-syscall-all-cpus.c
> > index 3644d6f52c07..0be43f8db3bd 100644
> > --- a/tools/perf/tests/openat-syscall-all-cpus.c
> > +++ b/tools/perf/tests/openat-syscall-all-cpus.c
> > @@ -22,7 +22,8 @@
> >  static int test__openat_syscall_event_on_all_cpus(struct test_suite *test __maybe_unused,
> >                                                 int subtest __maybe_unused)
> >  {
> > -     int err = TEST_FAIL, fd, idx;
> > +     int err = TEST_FAIL, fd;
> > +     unsigned int idx;
> >       struct perf_cpu cpu;
> >       struct perf_cpu_map *cpus;
> >       struct evsel *evsel;
> > diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c
> > index ec01150d208d..9e6a0031e9ec 100644
> > --- a/tools/perf/tests/topology.c
> > +++ b/tools/perf/tests/topology.c
> > @@ -67,7 +67,7 @@ static int check_cpu_topology(char *path, struct perf_cpu_map *map)
> >               .path = path,
> >               .mode = PERF_DATA_MODE_READ,
> >       };
> > -     int i;
> > +     unsigned int i;
> >       struct aggr_cpu_id id;
> >       struct perf_cpu cpu;
> >       struct perf_env *env;
> > @@ -114,7 +114,7 @@ static int check_cpu_topology(char *path, struct perf_cpu_map *map)
> >
> >       TEST_ASSERT_VAL("Session header CPU map not set", env->cpu);
> >
> > -     for (i = 0; i < env->nr_cpus_avail; i++) {
> > +     for (i = 0; i < (unsigned int)env->nr_cpus_avail; i++) {
> >               cpu.cpu = i;
> >               if (!perf_cpu_map__has(map, cpu))
> >                       continue;
> > diff --git a/tools/perf/util/affinity.c b/tools/perf/util/affinity.c
> > index 4fe851334296..6c64b5f69a4e 100644
> > --- a/tools/perf/util/affinity.c
> > +++ b/tools/perf/util/affinity.c
> > @@ -90,7 +90,7 @@ void cpu_map__set_affinity(const struct perf_cpu_map *cpumap)
> >       int cpu_set_size = get_cpu_set_size();
> >       unsigned long *cpuset = bitmap_zalloc(cpu_set_size * 8);
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       if (!cpuset)
> >               return;
> > diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
> > index a5882b582205..2ffd7aefb6eb 100644
> > --- a/tools/perf/util/bpf_counter.c
> > +++ b/tools/perf/util/bpf_counter.c
> > @@ -294,7 +294,8 @@ static int bpf_program_profiler__read(struct evsel *evsel)
> >       struct perf_counts_values *counts;
> >       int reading_map_fd;
> >       __u32 key = 0;
> > -     int err, idx, bpf_cpu;
> > +     int err, bpf_cpu;
> > +     unsigned int idx;
> >
> >       if (list_empty(&evsel->bpf_counter_list))
> >               return -EAGAIN;
> > @@ -318,11 +319,12 @@ static int bpf_program_profiler__read(struct evsel *evsel)
> >               }
> >
> >               for (bpf_cpu = 0; bpf_cpu < num_cpu_bpf; bpf_cpu++) {
> > -                     idx = perf_cpu_map__idx(evsel__cpus(evsel),
> > -                                             (struct perf_cpu){.cpu = bpf_cpu});
> > -                     if (idx == -1)
> > +                     int i = perf_cpu_map__idx(evsel__cpus(evsel),
> > +                                               (struct perf_cpu){.cpu = bpf_cpu});
> > +
> > +                     if (i == -1)
> >                               continue;
> > -                     counts = perf_counts(evsel->counts, idx, 0);
> > +                     counts = perf_counts(evsel->counts, i, 0);
> >                       counts->val += values[bpf_cpu].counter;
> >                       counts->ena += values[bpf_cpu].enabled;
> >                       counts->run += values[bpf_cpu].running;
> > @@ -668,7 +670,7 @@ static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
> >  static int bperf_sync_counters(struct evsel *evsel)
> >  {
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus)
> >               bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu.cpu);
> > @@ -695,13 +697,11 @@ static int bperf__read(struct evsel *evsel)
> >       struct bpf_perf_event_value values[num_cpu_bpf];
> >       struct perf_counts_values *counts;
> >       int reading_map_fd, err = 0;
> > -     __u32 i;
> > -     int j;
> >
> >       bperf_sync_counters(evsel);
> >       reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
> >
> > -     for (i = 0; i < filter_entry_cnt; i++) {
> > +     for (__u32 i = 0; i < filter_entry_cnt; i++) {
> >               struct perf_cpu entry;
> >               __u32 cpu;
> >
> > @@ -709,9 +709,10 @@ static int bperf__read(struct evsel *evsel)
> >               if (err)
> >                       goto out;
> >               switch (evsel->follower_skel->bss->type) {
> > -             case BPERF_FILTER_GLOBAL:
> > -                     assert(i == 0);
> > +             case BPERF_FILTER_GLOBAL: {
> > +                     unsigned int j;
> >
> > +                     assert(i == 0);
> >                       perf_cpu_map__for_each_cpu(entry, j, evsel__cpus(evsel)) {
> >                               counts = perf_counts(evsel->counts, j, 0);
> >                               counts->val = values[entry.cpu].counter;
> > @@ -719,6 +720,7 @@ static int bperf__read(struct evsel *evsel)
> >                               counts->run = values[entry.cpu].running;
> >                       }
> >                       break;
> > +             }
> >               case BPERF_FILTER_CPU:
> >                       cpu = perf_cpu_map__cpu(evsel__cpus(evsel), i).cpu;
> >                       assert(cpu >= 0);
> > diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
> > index 17d7196c6589..5572ceccf860 100644
> > --- a/tools/perf/util/bpf_counter_cgroup.c
> > +++ b/tools/perf/util/bpf_counter_cgroup.c
> > @@ -98,7 +98,7 @@ static int bperf_load_program(struct evlist *evlist)
> >       struct bpf_link *link;
> >       struct evsel *evsel;
> >       struct cgroup *cgrp, *leader_cgrp;
> > -     int i, j;
> > +     unsigned int i;
> >       struct perf_cpu cpu;
> >       int total_cpus = cpu__max_cpu().cpu;
> >       int map_fd, prog_fd, err;
> > @@ -146,6 +146,8 @@ static int bperf_load_program(struct evlist *evlist)
> >
> >       evlist__for_each_entry(evlist, evsel) {
> >               if (cgrp == NULL || evsel->cgrp == leader_cgrp) {
> > +                     unsigned int j;
> > +
> >                       leader_cgrp = evsel->cgrp;
> >                       evsel->cgrp = NULL;
> >
> > @@ -234,7 +236,7 @@ static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused,
> >  static int bperf_cgrp__sync_counters(struct evlist *evlist)
> >  {
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >       int prog_fd = bpf_program__fd(skel->progs.trigger_read);
> >
> >       perf_cpu_map__for_each_cpu(cpu, idx, evlist->core.all_cpus)
> > @@ -286,7 +288,7 @@ static int bperf_cgrp__read(struct evsel *evsel)
> >
> >       evlist__for_each_entry(evlist, evsel) {
> >               __u32 idx = evsel->core.idx;
> > -             int i;
> > +             unsigned int i;
> >               struct perf_cpu cpu;
> >
> >               err = bpf_map_lookup_elem(reading_map_fd, &idx, values);
> > diff --git a/tools/perf/util/bpf_kwork.c b/tools/perf/util/bpf_kwork.c
> > index 5cff755c71fa..d3a2e548f2b6 100644
> > --- a/tools/perf/util/bpf_kwork.c
> > +++ b/tools/perf/util/bpf_kwork.c
> > @@ -148,7 +148,8 @@ static bool valid_kwork_class_type(enum kwork_class_type type)
> >  static int setup_filters(struct perf_kwork *kwork)
> >  {
> >       if (kwork->cpu_list != NULL) {
> > -             int idx, nr_cpus;
> > +             unsigned int idx;
> > +             int nr_cpus;
> >               struct perf_cpu_map *map;
> >               struct perf_cpu cpu;
> >               int fd = bpf_map__fd(skel->maps.perf_kwork_cpu_filter);
> > diff --git a/tools/perf/util/bpf_kwork_top.c b/tools/perf/util/bpf_kwork_top.c
> > index b6f187dd9136..189a29d2bc96 100644
> > --- a/tools/perf/util/bpf_kwork_top.c
> > +++ b/tools/perf/util/bpf_kwork_top.c
> > @@ -123,7 +123,8 @@ static bool valid_kwork_class_type(enum kwork_class_type type)
> >  static int setup_filters(struct perf_kwork *kwork)
> >  {
> >       if (kwork->cpu_list) {
> > -             int idx, nr_cpus, fd;
> > +             unsigned int idx;
> > +             int nr_cpus, fd;
> >               struct perf_cpu_map *map;
> >               struct perf_cpu cpu;
> >
> > diff --git a/tools/perf/util/bpf_off_cpu.c b/tools/perf/util/bpf_off_cpu.c
> > index 88e0660c4bff..0891d9c73660 100644
> > --- a/tools/perf/util/bpf_off_cpu.c
> > +++ b/tools/perf/util/bpf_off_cpu.c
> > @@ -67,7 +67,7 @@ static void off_cpu_start(void *arg)
> >       struct evlist *evlist = arg;
> >       struct evsel *evsel;
> >       struct perf_cpu pcpu;
> > -     int i;
> > +     unsigned int i;
> >
> >       /* update task filter for the given workload */
> >       if (skel->rodata->has_task && skel->rodata->uses_tgid &&
> > diff --git a/tools/perf/util/bpf_trace_augment.c b/tools/perf/util/bpf_trace_augment.c
> > index 56ed17534caa..9e706f0fa53d 100644
> > --- a/tools/perf/util/bpf_trace_augment.c
> > +++ b/tools/perf/util/bpf_trace_augment.c
> > @@ -60,7 +60,7 @@ int augmented_syscalls__create_bpf_output(struct evlist *evlist)
> >  void augmented_syscalls__setup_bpf_output(void)
> >  {
> >       struct perf_cpu cpu;
> > -     int i;
> > +     unsigned int i;
> >
> >       if (bpf_output == NULL)
> >               return;
> > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> > index a80845038a5e..11922e1ded84 100644
> > --- a/tools/perf/util/cpumap.c
> > +++ b/tools/perf/util/cpumap.c
> > @@ -254,7 +254,7 @@ struct cpu_aggr_map *cpu_aggr_map__new(const struct perf_cpu_map *cpus,
> >                                      aggr_cpu_id_get_t get_id,
> >                                      void *data, bool needs_sort)
> >  {
> > -     int idx;
> > +     unsigned int idx;
> >       struct perf_cpu cpu;
> >       struct cpu_aggr_map *c = cpu_aggr_map__empty_new(perf_cpu_map__nr(cpus));
> >
> > @@ -280,7 +280,7 @@ struct cpu_aggr_map *cpu_aggr_map__new(const struct perf_cpu_map *cpus,
> >               }
> >       }
> >       /* Trim. */
> > -     if (c->nr != perf_cpu_map__nr(cpus)) {
> > +     if (c->nr != (int)perf_cpu_map__nr(cpus)) {
> >               struct cpu_aggr_map *trimmed_c =
> >                       realloc(c,
> >                               sizeof(struct cpu_aggr_map) + sizeof(struct aggr_cpu_id) * c->nr);
> > @@ -631,9 +631,9 @@ size_t cpu_map__snprint(struct perf_cpu_map *map, char *buf, size_t size)
> >
> >  #define COMMA first ? "" : ","
> >
> > -     for (i = 0; i < perf_cpu_map__nr(map) + 1; i++) {
> > +     for (i = 0; i < (int)perf_cpu_map__nr(map) + 1; i++) {
> >               struct perf_cpu cpu = { .cpu = INT16_MAX };
> > -             bool last = i == perf_cpu_map__nr(map);
> > +             bool last = i == (int)perf_cpu_map__nr(map);
> >
> >               if (!last)
> >                       cpu = perf_cpu_map__cpu(map, i);
> > @@ -679,7 +679,7 @@ static char hex_char(unsigned char val)
> >
> >  size_t cpu_map__snprint_mask(struct perf_cpu_map *map, char *buf, size_t size)
> >  {
> > -     int idx;
> > +     unsigned int idx;
> >       char *ptr = buf;
> >       unsigned char *bitmap;
> >       struct perf_cpu c, last_cpu = perf_cpu_map__max(map);
> > diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
> > index 8bbeb2dc76fd..e0091804fe98 100644
> > --- a/tools/perf/util/cputopo.c
> > +++ b/tools/perf/util/cputopo.c
> > @@ -191,7 +191,7 @@ bool cpu_topology__core_wide(const struct cpu_topology *topology,
> >               const char *core_cpu_list = topology->core_cpus_list[i];
> >               struct perf_cpu_map *core_cpus = perf_cpu_map__new(core_cpu_list);
> >               struct perf_cpu cpu;
> > -             int idx;
> > +             unsigned int idx;
> >               bool has_first, first = true;
> >
> >               perf_cpu_map__for_each_cpu(cpu, idx, core_cpus) {
> > diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> > index 93d475a80f14..1e54e2c86360 100644
> > --- a/tools/perf/util/env.c
> > +++ b/tools/perf/util/env.c
> > @@ -718,7 +718,7 @@ int perf_env__numa_node(struct perf_env *env, struct perf_cpu cpu)
> >
> >               for (i = 0; i < env->nr_numa_nodes; i++) {
> >                       struct perf_cpu tmp;
> > -                     int j;
> > +                     unsigned int j;
> >
> >                       nn = &env->numa_nodes[i];
> >                       perf_cpu_map__for_each_cpu(tmp, j, nn->map)
> > diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> > index 2b0df7bd9a46..5a30caaec73e 100644
> > --- a/tools/perf/util/scripting-engines/trace-event-python.c
> > +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> > @@ -1701,7 +1701,7 @@ static void python_process_stat(struct perf_stat_config *config,
> >       struct perf_cpu_map *cpus = counter->core.cpus;
> >
> >       for (int thread = 0; thread < perf_thread_map__nr(threads); thread++) {
> > -             int idx;
> > +             unsigned int idx;
> >               struct perf_cpu cpu;
> >
> >               perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
> > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> > index 4b465abfa36c..09de5288f9e1 100644
> > --- a/tools/perf/util/session.c
> > +++ b/tools/perf/util/session.c
> > @@ -2766,7 +2766,8 @@ struct evsel *perf_session__find_first_evtype(struct perf_session *session,
> >  int perf_session__cpu_bitmap(struct perf_session *session,
> >                            const char *cpu_list, unsigned long *cpu_bitmap)
> >  {
> > -     int i, err = -1;
> > +     unsigned int i;
> > +     int err = -1;
> >       struct perf_cpu_map *map;
> >       int nr_cpus = min(perf_session__env(session)->nr_cpus_avail, MAX_NR_CPUS);
> >       struct perf_cpu cpu;
> > diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
> > index dc2b66855f6c..993f4c4b8f44 100644
> > --- a/tools/perf/util/stat-display.c
> > +++ b/tools/perf/util/stat-display.c
> > @@ -897,7 +897,7 @@ static bool should_skip_zero_counter(struct perf_stat_config *config,
> >                                    const struct aggr_cpu_id *id)
> >  {
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       /*
> >        * Skip unsupported default events when not verbose. (default events
> > @@ -1125,7 +1125,7 @@ static void print_no_aggr_metric(struct perf_stat_config *config,
> >                                struct evlist *evlist,
> >                                struct outstate *os)
> >  {
> > -     int all_idx;
> > +     unsigned int all_idx;
> >       struct perf_cpu cpu;
> >
> >       perf_cpu_map__for_each_cpu(cpu, all_idx, evlist->core.user_requested_cpus) {
> > diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> > index 976a06e63252..14d169e22e8f 100644
> > --- a/tools/perf/util/stat.c
> > +++ b/tools/perf/util/stat.c
> > @@ -246,9 +246,11 @@ void evlist__reset_prev_raw_counts(struct evlist *evlist)
> >
> >  static void evsel__copy_prev_raw_counts(struct evsel *evsel)
> >  {
> > -     int idx, nthreads = perf_thread_map__nr(evsel->core.threads);
> > +     int nthreads = perf_thread_map__nr(evsel->core.threads);
> >
> >       for (int thread = 0; thread < nthreads; thread++) {
> > +             unsigned int idx;
> > +
> >               perf_cpu_map__for_each_idx(idx, evsel__cpus(evsel)) {
> >                       *perf_counts(evsel->counts, idx, thread) =
> >                               *perf_counts(evsel->prev_raw_counts, idx, thread);
> > @@ -580,7 +582,7 @@ static void evsel__update_percore_stats(struct evsel *evsel, struct aggr_cpu_id
> >       struct perf_counts_values counts = { 0, };
> >       struct aggr_cpu_id id;
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       /* collect per-core counts */
> >       perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus) {
> > @@ -617,7 +619,7 @@ static void evsel__process_percore(struct evsel *evsel)
> >       struct perf_stat_evsel *ps = evsel->stats;
> >       struct aggr_cpu_id core_id;
> >       struct perf_cpu cpu;
> > -     int idx;
> > +     unsigned int idx;
> >
> >       if (!evsel->percore)
> >               return;
> > diff --git a/tools/perf/util/svghelper.c b/tools/perf/util/svghelper.c
> > index b1d259f590e9..e360e7736c7b 100644
> > --- a/tools/perf/util/svghelper.c
> > +++ b/tools/perf/util/svghelper.c
> > @@ -726,7 +726,8 @@ static void scan_core_topology(int *map, struct topology *t, int nr_cpus)
> >
> >  static int str_to_bitmap(char *s, cpumask_t *b, int nr_cpus)
> >  {
> > -     int idx, ret = 0;
> > +     unsigned int idx;
> > +     int ret = 0;
> >       struct perf_cpu_map *map;
> >       struct perf_cpu cpu;
> >
> > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> > index bd811b2b7890..467517f4996a 100644
> > --- a/tools/perf/util/symbol.c
> > +++ b/tools/perf/util/symbol.c
> > @@ -2364,7 +2364,8 @@ static int setup_parallelism_bitmap(void)
> >  {
> >       struct perf_cpu_map *map;
> >       struct perf_cpu cpu;
> > -     int i, err = -1;
> > +     unsigned int i;
> > +     int err = -1;
> >
> >       if (symbol_conf.parallelism_list_str == NULL)
> >               return 0;
> > diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
> > index ef79433ebc3a..912fd4414937 100644
> > --- a/tools/perf/util/synthetic-events.c
> > +++ b/tools/perf/util/synthetic-events.c
> > @@ -1261,7 +1261,7 @@ static void synthesize_cpus(struct synthesize_cpu_map_data *data)
> >
> >  static void synthesize_mask(struct synthesize_cpu_map_data *data)
> >  {
> > -     int idx;
> > +     unsigned int idx;
> >       struct perf_cpu cpu;
> >
> >       /* Due to padding, the 4bytes per entry mask variant is always smaller. */
> > --
> > 2.53.0.851.ga537e3e6e9-goog
> >