perf diff: Make hist_entry_diff fields union

The period_ratio_delta, period_ratio and wdiff are never by used at the
same time.  Instead, Just one of them is accessed according to a
comparison method.  So make it union to reduce memory footprint.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1429416255-12070-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index af192f172fa2995d65eca8a6fa25d77990438eaf..de3303fe726d4e9b52476c58e6f6217f6d1d7095 100644 (file)
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -58,15 +58,16 @@ struct he_stat {
 
 struct hist_entry_diff {
        bool    computed;
+       union {
+               /* PERF_HPP__DELTA */
+               double  period_ratio_delta;
 
-       /* PERF_HPP__DELTA */
-       double  period_ratio_delta;
-
-       /* PERF_HPP__RATIO */
-       double  period_ratio;
+               /* PERF_HPP__RATIO */
+               double  period_ratio;
 
-       /* HISTC_WEIGHTED_DIFF */
-       s64     wdiff;
+               /* HISTC_WEIGHTED_DIFF */
+               s64     wdiff;
+       };
 };
 
 /**