Re: [PATCH V2 19/23] libperf evlist: Check nr_mmaps is correct

[Ian Rogers]

On Fri, May 6, 2022 at 5:26 AM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> Print an error message if the predetermined number of mmaps is
> incorrect.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> ---
>  tools/lib/perf/evlist.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
> index eae1f6179dad..f51fdb899d19 100644
> --- a/tools/lib/perf/evlist.c
> +++ b/tools/lib/perf/evlist.c
> @@ -23,6 +23,7 @@
>  #include <perf/cpumap.h>
>  #include <perf/threadmap.h>
>  #include <api/fd/array.h>
> +#include "internal.h"
>
>  void perf_evlist__init(struct perf_evlist *evlist)
>  {
> @@ -428,7 +429,7 @@ static void perf_evlist__set_mmap_first(struct perf_evlist *evlist, struct perf_
>  static int
>  mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
>                int idx, struct perf_mmap_param *mp, int cpu_idx,
> -              int thread, int *_output, int *_output_overwrite)
> +              int thread, int *_output, int *_output_overwrite, int *nr_mmaps)
>  {
>         struct perf_cpu evlist_cpu = perf_cpu_map__cpu(evlist->all_cpus, cpu_idx);
>         struct perf_evsel *evsel;
> @@ -484,6 +485,8 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
>                         if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
>                                 return -1;
>
> +                       *nr_mmaps += 1;
> +
>                         if (!idx)
>                                 perf_evlist__set_mmap_first(evlist, map, overwrite);
>                 } else {
> @@ -518,6 +521,7 @@ mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
>  {
>         int nr_threads = perf_thread_map__nr(evlist->threads);
>         int nr_cpus    = perf_cpu_map__nr(evlist->all_cpus);
> +       int nr_mmaps = 0;
>         int cpu, thread;
>
>         for (cpu = 0; cpu < nr_cpus; cpu++) {
> @@ -526,11 +530,14 @@ mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
>
>                 for (thread = 0; thread < nr_threads; thread++) {
>                         if (mmap_per_evsel(evlist, ops, cpu, mp, cpu,
> -                                          thread, &output, &output_overwrite))
> +                                          thread, &output, &output_overwrite, &nr_mmaps))
>                                 goto out_unmap;
>                 }
>         }
>
> +       if (nr_mmaps != evlist->nr_mmaps)
> +               pr_err("Miscounted nr_mmaps %d vs %d\n", nr_mmaps, evlist->nr_mmaps);
> +
>         return 0;
>
>  out_unmap:
> --
> 2.25.1
>