Changeset 418 for branches/performance

Timestamp:

10/15/06 08:45:01 (3 years ago)

Author:

sgrimm

Message:

Only reposition items in the LRU queue once a minute. This reduces the number
of memory writes required to handle frequently-accessed items.

Files:

• branches/performance/server/items.c (modified) (2 diffs)

branches/performance/server/items.c

@@ -20 +20 @@
 #include "memcached.h"
 
+/*
+ * We only reposition items in the LRU queue if they haven't been repositioned
+ * in this many seconds. That saves us from churning on frequently-accessed
+ * items.
+ */
+#define ITEM_UPDATE_INTERVAL 60
 
 #define LARGEST_ID 255
@@ -217 +223 @@
 
 void item_update(item *it) {
-    assert((it->it_flags & ITEM_SLABBED) == 0);
-
-    item_unlink_q(it);
-    it->time = current_time;
-    item_link_q(it);
+    if (it->time < current_time - ITEM_UPDATE_INTERVAL) {
+        assert((it->it_flags & ITEM_SLABBED) == 0);
+
+        item_unlink_q(it);
+        it->time = current_time;
+        item_link_q(it);
+    }
 }