perf hists: Check if accumulated when adding a hist entry

To support callchain accumulation, @entry should be recognized if it's
accumulated or not when add_hist_entry() called.  The period of an
accumulated entry should be added to ->stat_acc but not ->stat. Add
@sample_self arg for that.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arun Sharma <asharma@fb.com>
Tested-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-5-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 8bff543..9a5a035 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -315,7 +315,7 @@
 			    u64 weight, u64 transaction)
 {
 	if (__hists__add_entry(hists, al, NULL, NULL, NULL, period, weight,
-			       transaction) != NULL)
+			       transaction, true) != NULL)
 		return 0;
 	return -ENOMEM;
 }