perf stat: Fix zero total printouts

Before:

           0  sched:sched_switch #        nan M/sec

After:

           0  sched:sched_switch #      0.000 M/sec

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 14 insertions, 4 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 16af2d82e858..e5f6ece65a13 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -338,14 +338,24 @@ static void nsec_printout(int counter, double avg)
 
 static void abs_printout(int counter, double avg)
 {
+        double total, ratio = 0.0;
+
         fprintf(stderr, " %14.0f  %-24s", avg, event_name(counter));
 
         if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
-                fprintf(stderr, " # %10.3f IPC  ",
-                                avg / avg_stats(&runtime_cycles_stats));
+                total = avg_stats(&runtime_cycles_stats);
+
+                if (total)
+                        ratio = avg / total;
+
+                fprintf(stderr, " # %10.3f IPC  ", ratio);
         } else {
-                fprintf(stderr, " # %10.3f M/sec",
-                                1000.0 * avg / avg_stats(&runtime_nsecs_stats));
+                total = avg_stats(&runtime_nsecs_stats);
+
+                if (total)
+                        ratio = 1000.0 * avg / total;
+
+                fprintf(stderr, " # %10.3f M/sec", ratio);
         }
 }