Re: [PATCH 3/5] perf tools: Reference count map_groups objects

[David Ahern <dsahern@gmail.com>]

On 4/14/14, 9:52 AM, Jiri Olsa wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
>
> We will share it among threads in the same process.
>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Don Zickus <dzickus@redhat.com>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Mike Galbraith <efault@gmx.de>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Stephane Eranian <eranian@google.com>
> Signed-off-by: Jiri Olsa <jolsa@redhat.com>
> ---
>   tools/perf/util/map.c    | 7 +++++++
>   tools/perf/util/map.h    | 9 +++++++++
>   tools/perf/util/thread.c | 2 +-
>   3 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index ae4c5e1..ba5f5c0c 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -323,6 +323,7 @@ void map_groups__init(struct map_groups *mg)
>   		INIT_LIST_HEAD(&mg->removed_maps[i]);
>   	}
>   	mg->machine = NULL;
> +	mg->refcnt = 1;
>   }
>
>   static void maps__delete(struct rb_root *maps)
> @@ -374,6 +375,12 @@ void map_groups__delete(struct map_groups *mg)
>   	free(mg);
>   }
>
> +void map_groups__put(struct map_groups *mg)
> +{
> +	if (--mg->refcnt == 0)
> +		map_groups__delete(mg);
> +}
> +
>   void map_groups__flush(struct map_groups *mg)
>   {
>   	int type;
> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
> index 1073e2d..d6445b2 100644
> --- a/tools/perf/util/map.h
> +++ b/tools/perf/util/map.h
> @@ -59,11 +59,20 @@ struct map_groups {
>   	struct rb_root	 maps[MAP__NR_TYPES];
>   	struct list_head removed_maps[MAP__NR_TYPES];
>   	struct machine	 *machine;
> +	int		 refcnt;
>   };


atomic for refcnt? This is part of a libperf; would be good to support 
multithreaded users.

David