perf hists browser: Fix percentage update on key press

Currently 'perf top --tui' decrements percentage of all entries on any
key press.  This is because it adds total period as new samples are
added to hists.  As perf-top does it currently but added samples are not
passed to the display thread, the percentages are decresing
continuously.

So separate total period stat into a different variable so that it
cannot affect the output total period.  This new total period stats are
used only for calcualating callchain percent limit.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 0f58474ec835 ("perf hists: Update hists' total period when adding entries")
Link: http://lkml.kernel.org/r/1455631723-17345-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 840b6d6..045a9e7 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -66,6 +66,8 @@
 	struct rb_root		entries_collapsed;
 	u64			nr_entries;
 	u64			nr_non_filtered_entries;
+	u64			callchain_period;
+	u64			callchain_non_filtered_period;
 	struct thread		*thread_filter;
 	const struct dso	*dso_filter;
 	const char		*uid_filter_str;