Re: [PATCH v3 5/9] perf build-id: Mark DSO in sample callchains

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Apr 28, 2025 at 02:34:04PM -0700, Ian Rogers wrote:
> Previously only the sample IP's map DSO would be marked hit for the
> purposes of populating the build ID cache. Walk the call chain to mark
> all IPs and DSOs.

I think this is correct, but I'm afraid it'd also increase the processing
time.  Do you happen to have any numbers?

Thanks,
Namhyung

> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/build-id.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index aa35dceace90..3386fa8e1e7e 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -42,10 +42,20 @@
>  
>  static bool no_buildid_cache;
>  
> +static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data __maybe_unused)
> +{
> +	struct map *map = node->ms.map;
> +
> +	if (map)
> +		dso__set_hit(map__dso(map));
> +
> +	return 0;
> +}
> +
>  int build_id__mark_dso_hit(const struct perf_tool *tool __maybe_unused,
>  			   union perf_event *event,
>  			   struct perf_sample *sample,
> -			   struct evsel *evsel __maybe_unused,
> +			   struct evsel *evsel,
>  			   struct machine *machine)
>  {
>  	struct addr_location al;
> @@ -63,6 +73,11 @@ int build_id__mark_dso_hit(const struct perf_tool *tool __maybe_unused,
>  		dso__set_hit(map__dso(al.map));
>  
>  	addr_location__exit(&al);
> +
> +	sample__for_each_callchain_node(thread, evsel, sample, PERF_MAX_STACK_DEPTH,
> +					/*symbols=*/false, mark_dso_hit_callback, /*data=*/NULL);
> +
> +
>  	thread__put(thread);
>  	return 0;
>  }
> -- 
> 2.49.0.901.g37484f566f-goog
>