diff --git a/src/backend/storage/buffer/buf_init.c b/src/backend/storage/buffer/buf_init.c
index 94cefba..9332a74 100644
--- a/src/backend/storage/buffer/buf_init.c
+++ b/src/backend/storage/buffer/buf_init.c
@@ -115,7 +115,7 @@ InitBufferPool(void)
 			 * Initially link all the buffers together as unused. Subsequent
 			 * management of this list is done by freelist.c.
 			 */
-			buf->freeNext = i + 1;
+			StrategyInitFreelistBuffer(buf);
 
 			buf->io_in_progress_lock = LWLockAssign();
 			buf->content_lock = LWLockAssign();
diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c
index 3e62448..6b49cae 100644
--- a/src/backend/storage/buffer/freelist.c
+++ b/src/backend/storage/buffer/freelist.c
@@ -27,6 +27,7 @@ typedef struct
 	/* Clock sweep hand: index of next buffer to consider grabbing */
 	int			nextVictimBuffer;
 
+#ifdef USE_BUFMGR_FREELIST
 	int			firstFreeBuffer;	/* Head of list of unused buffers */
 	int			lastFreeBuffer; /* Tail of list of unused buffers */
 
@@ -34,7 +35,7 @@ typedef struct
 	 * NOTE: lastFreeBuffer is undefined when firstFreeBuffer is -1 (that is,
 	 * when the list is empty)
 	 */
-
+#endif
 	/*
 	 * Statistics.	These counters should be wide enough that they can't
 	 * overflow during a single bgwriter cycle.
@@ -134,6 +135,7 @@ StrategyGetBuffer(BufferAccessStrategy strategy, bool *lock_held)
 	 */
 	StrategyControl->numBufferAllocs++;
 
+#ifdef USE_BUFMGR_FREELIST
 	/*
 	 * Try to get a buffer from the freelist.  Note that the freeNext fields
 	 * are considered to be protected by the BufFreelistLock not the
@@ -165,8 +167,9 @@ StrategyGetBuffer(BufferAccessStrategy strategy, bool *lock_held)
 		}
 		UnlockBufHdr(buf);
 	}
+#endif
 
-	/* Nothing on the freelist, so run the "clock sweep" algorithm */
+	/* Run the "clock sweep" algorithm */
 	trycounter = NBuffers;
 	for (;;)
 	{
@@ -182,20 +185,25 @@ StrategyGetBuffer(BufferAccessStrategy strategy, bool *lock_held)
 		 * If the buffer is pinned or has a nonzero usage_count, we cannot use
 		 * it; decrement the usage_count (unless pinned) and keep scanning.
 		 */
-		LockBufHdr(buf);
 		if (buf->refcount == 0)
 		{
-			if (buf->usage_count > 0)
+			if (buf->usage_count > StrategyControl->completePasses)
 			{
 				buf->usage_count--;
 				trycounter = NBuffers;
 			}
 			else
 			{
-				/* Found a usable buffer */
-				if (strategy != NULL)
-					AddBufferToRing(strategy, buf);
-				return buf;
+				LockBufHdr(buf);
+				if (buf->refcount == 0)
+				{
+					UnlockBufHdr(buf);
+					/* Found a usable buffer */
+					if (strategy != NULL)
+						AddBufferToRing(strategy, buf);
+					return buf;
+				}
+				UnlockBufHdr(buf);
 			}
 		}
 		else if (--trycounter == 0)
@@ -207,10 +215,8 @@ StrategyGetBuffer(BufferAccessStrategy strategy, bool *lock_held)
 			 * probably better to fail than to risk getting stuck in an
 			 * infinite loop.
 			 */
-			UnlockBufHdr(buf);
 			elog(ERROR, "no unpinned buffers available");
 		}
-		UnlockBufHdr(buf);
 	}
 
 	/* not reached */
@@ -223,6 +229,7 @@ StrategyGetBuffer(BufferAccessStrategy strategy, bool *lock_held)
 void
 StrategyFreeBuffer(volatile BufferDesc *buf)
 {
+#ifdef USE_BUFMGR_FREELIST
 	LWLockAcquire(BufFreelistLock, LW_EXCLUSIVE);
 
 	/*
@@ -238,6 +245,24 @@ StrategyFreeBuffer(volatile BufferDesc *buf)
 	}
 
 	LWLockRelease(BufFreelistLock);
+#endif
+}
+
+/*
+ * StrategyInitFreelist: put a buffer on the freelist during InitBufferPool
+ */
+void
+StrategyInitFreelistBuffer(volatile BufferDesc *buf)
+{
+#ifdef USE_BUFMGR_FREELIST
+	/*
+	 * Initially link all the buffers together as unused. Subsequent
+	 * management of this list is done by freelist.c.
+	 */
+	buf->freeNext = i + 1;
+#else
+	buf->freeNext = FREENEXT_NOT_IN_LIST;
+#endif
 }
 
 /*
@@ -331,12 +356,14 @@ StrategyInitialize(bool init)
 		 */
 		Assert(init);
 
+#ifdef USE_BUFMGR_FREELIST
 		/*
 		 * Grab the whole linked list of free buffers for our strategy. We
 		 * assume it was previously set up by InitBufferPool().
 		 */
 		StrategyControl->firstFreeBuffer = 0;
 		StrategyControl->lastFreeBuffer = NBuffers - 1;
+#endif
 
 		/* Initialize the clock sweep pointer */
 		StrategyControl->nextVictimBuffer = 0;
diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h
index e43719e..6a03d5d 100644
--- a/src/include/storage/buf_internals.h
+++ b/src/include/storage/buf_internals.h
@@ -190,6 +190,8 @@ extern bool StrategyRejectBuffer(BufferAccessStrategy strategy,
 extern int	StrategySyncStart(uint32 *complete_passes, uint32 *num_buf_alloc);
 extern Size StrategyShmemSize(void);
 extern void StrategyInitialize(bool init);
+extern void StrategyInitFreelistBuffer(volatile BufferDesc *buf);
+
 
 /* buf_table.c */
 extern Size BufTableShmemSize(int size);