[Qemu-devel] [PATCH 33/34] scripts/kvm/kvm_stat: Fixup filtering

[Janosch Frank]

When filtering, the group leader event should not be disabled, as all
other events under it will also be disabled. Also we should make sure
that values from disabled fields will not be displayed.

This also filters the fields from the log and batch output for better
readability.

Also the drilldown update now directly checks for the stats' field
filter and (un)sets drilldown accordingly.
---
 scripts/kvm/kvm_stat | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
index 616ecb4..556e5ca 100755
--- a/scripts/kvm/kvm_stat
+++ b/scripts/kvm/kvm_stat
@@ -450,6 +450,9 @@ class TracepointProvider(object):
                 group.add_event(event_data)
             self.group_leaders.append(group)
 
+    def available_fields(self):
+        return self.get_available_fields()
+
     @property
     def fields(self):
         return self._fields
@@ -458,23 +461,30 @@ class TracepointProvider(object):
     def fields(self, fields):
         self._fields = fields
         for group in self.group_leaders:
-            for event in group.events:
+            for index, event in enumerate(group.events):
                 if event.name in fields:
                     event.reset()
                     event.enable()
                 else:
-                    event.disable()
+                    # Do not disable the group leader.
+                    # It would disable all of its events.
+                    if index != 0:
+                        event.disable()
 
     def read(self):
         ret = defaultdict(int)
         for group in self.group_leaders:
             for name, val in group.read().iteritems():
-                ret[name] += val
+                if name in self._fields:
+                    ret[name] += val
         return ret
 
 class DebugfsProvider(object):
     def __init__(self):
-        self._fields = walkdir(PATH_DEBUGFS)[2]
+        self._fields = self.get_available_fields()
+
+    def get_available_fields(self):
+        return walkdir(PATH_DEBUGFS)[2]
 
     @property
     def fields(self):
@@ -506,7 +516,8 @@ class Stats(object):
         # also clear the cache of old values.
         self.values = {}
         for provider in self.providers:
-            provider_fields = [key for key in provider.fields if wanted(key)]
+            provider_fields = [key for key in provider.get_available_fields()
+                               if wanted(key)]
             provider.fields = provider_fields
 
     @property
@@ -540,15 +551,14 @@ class Tui(object):
         self.drilldown = False
         curses.use_default_colors()
         curses.noecho()
-        self.fields_filter = self.stats.fields_filter
         self.update_drilldown()
 
     def update_drilldown(self):
-        if not self.fields_filter:
-            if self.drilldown:
-                self.stats.fields_filter = None
-            else:
-                self.stats.fields_filter = r'^[^\(]*$'
+        if not self.stats.fields_filter:
+            self.stats.fields_filter = r'^[^\(]*$'
+
+        elif self.stats.fields_filter == r'^[^\(]*$':
+            self.stats.fields_filter = None
 
     def refresh(self, sleeptime):
         self.screen.erase()
-- 
2.3.0