[PATCH 1/8] tools/kvm_stat: fix crash when filtering out all non-child trace events

[Stefan Raspl <raspl@xxxxxxxxxxxxxxxxxx>]

From: Stefan Raspl <stefan.raspl@xxxxxxxxxx>

When we apply a filter that will only leave child trace events, we
receive a ZeroDivisionError when calculating the percentages.
In that case, provide percentages based on child events only.
To reproduce, run 'kvm_stat -f .*[\(].*'.

Signed-off-by: Stefan Raspl <raspl@xxxxxxxxxxxxxxxxxx>
---
 tools/kvm/kvm_stat/kvm_stat | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index f64feaa6d1b4..681c79a139c8 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -1084,9 +1084,15 @@ class Tui(object):
         self.screen.clrtobot()
         stats = self.stats.get(self._display_guests)
         total = 0.
+        ctotal = 0.
         for key, values in stats.items():
             if key.find('(') == -1:
                 total += values.value
+            else:
+                ctotal += values.value
+        if total == 0.:
+            # we don't have any fields, or all non-child events are filtered
+            total = ctotal
 
         if self._sorting == SORT_DEFAULT:
             def sortkey((_k, v)):
-- 
2.13.5