perf c2c: Use mem_info refcnt logic

Switch to refcnt logic instead of duplicating mem_info objects. No
functional change, just saving some memory.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180307155020.32613-7-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-c2c.c

@@ -237,9 +237,12 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused,
 	if (mi == NULL)
 		return -ENOMEM;
 
-	mi_dup = memdup(mi, sizeof(*mi));
-	if (!mi_dup)
-		goto free_mi;
+	/*
+	 * The mi object is released in hists__add_entry_ops,
+	 * if it gets sorted out into existing data, so we need
+	 * to take the copy now.
+	 */
+	mi_dup = mem_info__get(mi);
 
 	c2c_decode_stats(&stats, mi);
 
@@ -247,7 +250,7 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused,
 				  &al, NULL, NULL, mi,
 				  sample, true);
 	if (he == NULL)
-		goto free_mi_dup;
+		goto free_mi;
 
 	c2c_he = container_of(he, struct c2c_hist_entry, he);
 	c2c_add_stats(&c2c_he->stats, &stats);
@@ -272,19 +275,15 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused,
 
 		mi = mi_dup;
 
-		mi_dup = memdup(mi, sizeof(*mi));
-		if (!mi_dup)
-			goto free_mi;
-
 		c2c_hists = he__get_c2c_hists(he, c2c.cl_sort, 2);
 		if (!c2c_hists)
-			goto free_mi_dup;
+			goto free_mi;
 
 		he = hists__add_entry_ops(&c2c_hists->hists, &c2c_entry_ops,
 					  &al, NULL, NULL, mi,
 					  sample, true);
 		if (he == NULL)
-			goto free_mi_dup;
+			goto free_mi;
 
 		c2c_he = container_of(he, struct c2c_hist_entry, he);
 		c2c_add_stats(&c2c_he->stats, &stats);
@@ -303,10 +302,9 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused,
 	addr_location__put(&al);
 	return ret;
 
-free_mi_dup:
-	free(mi_dup);
 free_mi:
-	free(mi);
+	mem_info__put(mi_dup);
+	mem_info__put(mi);
 	ret = -ENOMEM;
 	goto out;
 }