Re: [PATCH RESEND 1/2] perf evlist: Return first evsel for non-sample event on old kernel

[Namhyung Kim <namhyung.kim@lge.com>]

Ping. :)


2012-02-20 10:47 AM, Namhyung Kim wrote:
> On old kernels that don't support sample_id_all feature,
> perf_evlist__id2evsel() returns NULL for non-sampling events.
> This breaks perf top when multiple events are given on command
> line. Fix it by using first evsel in the evlist. This will also
> prevent getting the same (potential) problem in such new tool/
> old kernel combo.
>
> Suggested-by: Arnaldo Carvalho de Melo<acme@ghostprotocols.net>
> Signed-off-by: Namhyung Kim<namhyung.kim@lge.com>
> ---
>   tools/perf/util/evlist.c |    4 ++++
>   1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 5c61dc57d7c7..f8da9fada002 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -349,6 +349,10 @@ struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
>   	hlist_for_each_entry(sid, pos, head, node)
>   		if (sid->id == id)
>   			return sid->evsel;
> +
> +	if (!perf_evlist__sample_id_all(evlist))
> +		return list_entry(evlist->entries.next, struct perf_evsel, node);
> +
>   	return NULL;
>   }
>