Re: [PATCH V14 08/11] perf tools: Add missing_features for aux_start_paused, aux_pause, aux_resume

[Leo Yan <leo.yan@arm.com>]

Hi Adrian,

On Tue, Oct 22, 2024 at 06:59:14PM +0300, Adrian Hunter wrote:
> 
> Display "feature is not supported" error message if aux_start_paused,
> aux_pause or aux_resume result in a perf_event_open() error.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Acked-by: Ian Rogers <irogers@google.com>
> Reviewed-by: Andi Kleen <ak@linux.intel.com>
> ---
> 
> 
> Changes in V13:
>         Add error message also in EOPNOTSUPP case (Leo)
> 
> 
>  tools/perf/util/evsel.c | 12 ++++++++++++
>  tools/perf/util/evsel.h |  1 +
>  2 files changed, 13 insertions(+)
> 
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 95593b55d9a7..88b31a005ac6 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2102,6 +2102,12 @@ bool evsel__detect_missing_features(struct evsel *evsel)
>                 perf_missing_features.inherit_sample_read = true;
>                 pr_debug2("Using PERF_SAMPLE_READ / :S modifier is not compatible with inherit, falling back to no-inherit.\n");
>                 return true;
> +       } else if (!perf_missing_features.aux_pause_resume &&
> +           (evsel->core.attr.aux_pause || evsel->core.attr.aux_resume ||
> +            evsel->core.attr.aux_start_paused)) {
> +               perf_missing_features.aux_pause_resume = true;
> +               pr_debug2_peo("Kernel has no aux_pause/aux_resume support, bailing out\n");
> +               return false;

This patch fails to apply on the latest perf-tools-next branch due to
conflict:

  https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git
  branch: perf-tools-next

You might need to rebase it on the latest code base.

Thanks,
Leo

>         } else if (!perf_missing_features.branch_counters &&
>             (evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS)) {
>                 perf_missing_features.branch_counters = true;
> @@ -3279,6 +3285,10 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
>                         return scnprintf(msg, size,
>         "%s: PMU Hardware doesn't support 'aux_output' feature",
>                                          evsel__name(evsel));
> +               if (evsel->core.attr.aux_action)
> +                       return scnprintf(msg, size,
> +       "%s: PMU Hardware doesn't support 'aux_action' feature",
> +                                       evsel__name(evsel));
>                 if (evsel->core.attr.sample_period != 0)
>                         return scnprintf(msg, size,
>         "%s: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'",
> @@ -3309,6 +3319,8 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
>                         return scnprintf(msg, size, "clockid feature not supported.");
>                 if (perf_missing_features.clockid_wrong)
>                         return scnprintf(msg, size, "wrong clockid (%d).", clockid);
> +               if (perf_missing_features.aux_pause_resume)
> +                       return scnprintf(msg, size, "The 'aux_pause / aux_resume' feature is not supported, update the kernel.");
>                 if (perf_missing_features.aux_output)
>                         return scnprintf(msg, size, "The 'aux_output' feature is not supported, update the kernel.");
>                 if (!target__has_cpu(target))
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 9fcaf417b277..87135012217d 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -205,6 +205,7 @@ struct perf_missing_features {
>         bool weight_struct;
>         bool read_lost;
>         bool branch_counters;
> +       bool aux_pause_resume;
>         bool inherit_sample_read;
>  };
> 
> --
> 2.43.0
> 
>