Re: [PATCH 2/2] perf x86/topdown: Refine helper arch_is_topdown_metrics()

From: Namhyung Kim
Date: Wed Oct 16 2024 - 13:38:13 EST


Hi Ian,

On Fri, Oct 11, 2024 at 11:02:07AM +0000, Dapeng Mi wrote:
> Leverage the existed function perf_pmu__name_from_config() to check if
> an event is topdown metrics event. perf_pmu__name_from_config() goes
> through the defined formats and figures out the config of pre-defined
> topdown events.
>
> This avoids to figure out the config of topdown pre-defined events with
> hard-coded format strings "event=" and "umask=" and provides more
> flexibility.
>
> Suggested-by: Ian Rogers <irogers@xxxxxxxxxx>
> Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>

Are you ok with this now?

Thanks,
Namhyung

> ---
> tools/perf/arch/x86/util/topdown.c | 39 +++++++-----------------------
> 1 file changed, 9 insertions(+), 30 deletions(-)
>
> diff --git a/tools/perf/arch/x86/util/topdown.c b/tools/perf/arch/x86/util/topdown.c
> index cb2c64928bc4..f63747d0abdf 100644
> --- a/tools/perf/arch/x86/util/topdown.c
> +++ b/tools/perf/arch/x86/util/topdown.c
> @@ -41,43 +41,22 @@ bool arch_is_topdown_slots(const struct evsel *evsel)
> return false;
> }
>
> -static int compare_topdown_event(void *vstate, struct pmu_event_info *info)
> -{
> - int *config = vstate;
> - int event = 0;
> - int umask = 0;
> - char *str;
> -
> - if (!strcasestr(info->name, "topdown"))
> - return 0;
> -
> - str = strcasestr(info->str, "event=");
> - if (str)
> - sscanf(str, "event=%x", &event);
> -
> - str = strcasestr(info->str, "umask=");
> - if (str)
> - sscanf(str, "umask=%x", &umask);
> -
> - if (event == 0 && *config == (event | umask << 8))
> - return 1;
> -
> - return 0;
> -}
> -
> bool arch_is_topdown_metrics(const struct evsel *evsel)
> {
> - struct perf_pmu *pmu = evsel__find_pmu(evsel);
> int config = evsel->core.attr.config;
> + const char *name_from_config;
> + struct perf_pmu *pmu;
>
> - if (!pmu || !pmu->is_core)
> + /* All topdown events have an event code of 0. */
> + if ((config & 0xFF) != 0)
> return false;
>
> - if (perf_pmu__for_each_event(pmu, false, &config,
> - compare_topdown_event))
> - return true;
> + pmu = evsel__find_pmu(evsel);
> + if (!pmu || !pmu->is_core)
> + return false;
>
> - return false;
> + name_from_config = perf_pmu__name_from_config(pmu, config);
> + return name_from_config && strcasestr(name_from_config, "topdown");
> }
>
> /*
> --
> 2.40.1
>