bundles/unbound: better caching

bundles/unbound/metadata.py

@@ -17,15 +17,19 @@ defaults = {
     },
     'unbound': {
         'max_ttl': 3600,
+        'cache_size': '512M',
     },
 }
 
 
 @metadata_reactor
-def cpu_cores_to_threads(metadata):
+def cpu_cores_to_config_values(metadata):
+    num_cpus = metadata.get('vm/cpu', 1)
+
     return {
         'unbound': {
-            'threads': metadata.get('vm/cpu', 1)*2,
+            'threads': num_cpus*2,
+            'cache_slabs': 2**(num_cpus-1).bit_length(),
         },
     }