From f47b3054e30ff49129596e3a703080ff6fa89588 Mon Sep 17 00:00:00 2001
From: bert hubert <bert.hubert@powerdns.com>
Date: Tue, 16 Aug 2016 14:30:41 +0200
Subject: [PATCH] limit packet cache cleaning to at most once every 30 seconds

---
 pdns/packetcache.hh | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pdns/packetcache.hh b/pdns/packetcache.hh
index 74e3770b24..14545b848b 100644
--- a/pdns/packetcache.hh
+++ b/pdns/packetcache.hh
@@ -70,8 +70,12 @@ public:
   int size(); //!< number of entries in the cache
   void cleanupIfNeeded()
   {
-    if(!(++d_ops % 300000))
-      cleanup();
+    if(!(++d_ops % 300000)) {
+      if(d_lastclean + 30 < time(0)) {
+        d_lastclean=time(0); 
+        cleanup();
+      }
+    }
   }
   void cleanup(); //!< force the cache to preen itself from expired packets
   int purge();
@@ -143,6 +147,7 @@ private:
   }
 
   AtomicCounter d_ops;
+  time_t d_lastclean{0}; // doesn't need to be atomic
   AtomicCounter *d_statnumhit;
   AtomicCounter *d_statnummiss;
   AtomicCounter *d_statnumentries;
-- 
2.47.2