Re: [PATCH] libperf: Fix perf_cpu_map__for_each_cpu macro

[Ian Rogers]

On Tue, Feb 15, 2022 at 7:37 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Tzvetomir Stoyanov reported an issue with using macro
> perf_cpu_map__for_each_cpu using private perf_cpu object.
>
> The issue is caused by recent change that wrapped cpu in struct
> perf_cpu to distinguish it from cpu indexes. We need to make
> struct perf_cpu public.
>
> Adding simple test for using perf_cpu_map__for_each_cpu
> macro.
>
> Fixes: 6d18804b963b ("perf cpumap: Give CPUs their own type")
> Reported-by: Tzvetomir Stoyanov <tz.stoyanov@xxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> ---
>  tools/lib/perf/include/internal/cpumap.h |  6 +-----
>  tools/lib/perf/include/perf/cpumap.h     |  5 +++++
>  tools/lib/perf/libperf.map               |  1 +
>  tools/lib/perf/tests/test-cpumap.c       | 11 +++++++++++
>  4 files changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/tools/lib/perf/include/internal/cpumap.h b/tools/lib/perf/include/internal/cpumap.h
> index 581f9ffb4237..1973a18c096b 100644
> --- a/tools/lib/perf/include/internal/cpumap.h
> +++ b/tools/lib/perf/include/internal/cpumap.h
> @@ -3,11 +3,7 @@
>  #define __LIBPERF_INTERNAL_CPUMAP_H
>
>  #include <linux/refcount.h>
> -
> -/** A wrapper around a CPU to avoid confusion with the perf_cpu_map's map's indices. */
> -struct perf_cpu {
> -       int cpu;
> -};
> +#include <perf/cpumap.h>
>
>  /**
>   * A sized, reference counted, sorted array of integers representing CPU
> diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h
> index 15b8faafd615..4a2edbdb5e2b 100644
> --- a/tools/lib/perf/include/perf/cpumap.h
> +++ b/tools/lib/perf/include/perf/cpumap.h
> @@ -7,6 +7,11 @@
>  #include <stdio.h>
>  #include <stdbool.h>
>
> +/** A wrapper around a CPU to avoid confusion with the perf_cpu_map's map's indices. */
> +struct perf_cpu {
> +       int cpu;
> +};
> +
>  LIBPERF_API struct perf_cpu_map *perf_cpu_map__dummy_new(void);
>  LIBPERF_API struct perf_cpu_map *perf_cpu_map__default_new(void);
>  LIBPERF_API struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list);
> diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map
> index 93696affda2e..6fa0d651576b 100644
> --- a/tools/lib/perf/libperf.map
> +++ b/tools/lib/perf/libperf.map
> @@ -2,6 +2,7 @@ LIBPERF_0.0.1 {
>         global:
>                 libperf_init;
>                 perf_cpu_map__dummy_new;
> +               perf_cpu_map__default_new;
>                 perf_cpu_map__get;
>                 perf_cpu_map__put;
>                 perf_cpu_map__new;
> diff --git a/tools/lib/perf/tests/test-cpumap.c b/tools/lib/perf/tests/test-cpumap.c
> index d39378eaf897..87b0510a556f 100644
> --- a/tools/lib/perf/tests/test-cpumap.c
> +++ b/tools/lib/perf/tests/test-cpumap.c
> @@ -14,6 +14,8 @@ static int libperf_print(enum libperf_print_level level,
>  int test_cpumap(int argc, char **argv)
>  {
>         struct perf_cpu_map *cpus;
> +       struct perf_cpu cpu;
> +       int idx;
>
>         __T_START;
>
> @@ -27,6 +29,15 @@ int test_cpumap(int argc, char **argv)
>         perf_cpu_map__put(cpus);
>         perf_cpu_map__put(cpus);
>
> +       cpus = perf_cpu_map__default_new();
> +       if (!cpus)
> +               return -1;
> +
> +       perf_cpu_map__for_each_cpu(cpu, idx, cpus)
> +               __T("wrong cpu number", cpu.cpu != -1);
> +
> +       perf_cpu_map__put(cpus);
> +
>         __T_END;
>         return tests_failed == 0 ? 0 : -1;
>  }
> --
> 2.35.1
>