*** a/src/backend/storage/buffer/bufmgr.c
--- b/src/backend/storage/buffer/bufmgr.c
***************
*** 1390,1395 **** BgBufferSync(void)
--- 1390,1396 ----
  	/* Variables for final smoothed_density update */
  	long		new_strategy_delta;
  	uint32		new_recent_alloc;
+ 	volatile BufferDesc *bufHdr;
  
  	/*
  	 * Find out where the freelist clock sweep currently is, and how many
***************
*** 1575,1580 **** BgBufferSync(void)
--- 1576,1582 ----
  	{
  		int			buffer_state = SyncOneBuffer(next_to_clean, true);
  
+ 		bufHdr = &BufferDescriptors[next_to_clean];
  		if (++next_to_clean >= NBuffers)
  		{
  			next_to_clean = 0;
***************
*** 1592,1598 **** BgBufferSync(void)
--- 1594,1603 ----
  			}
  		}
  		else if (buffer_state & BUF_REUSABLE)
+ 		{
  			reusable_buffers++;
+ 			StrategyMoveBufferToFreeListEnd (bufHdr);
+ 		}                                                                      
  	}
  
  	BgWriterStats.m_buf_written_clean += num_written;
*** a/src/backend/storage/buffer/freelist.c
--- b/src/backend/storage/buffer/freelist.c
***************
*** 259,264 **** StrategyFreeBuffer(volatile BufferDesc *buf)
--- 259,296 ----
  }
  
  /*
+  * StrategyMoveBufferToFreeListEnd: put a buffer on the end of freelist
+  */                                                                                      
+ void
+ StrategyMoveBufferToFreeListEnd(volatile BufferDesc *buf)                                
+ {
+ 	LWLockAcquire(BufFreelistLock, LW_EXCLUSIVE);                                    
+  	/*
+  	 * It is possible that we are told to put something in the freelist that
+  	 * is already in it; don't screw up the list if so.
+  	 */                    
+  	if (buf->freeNext == FREENEXT_NOT_IN_LIST)
+  	{                   
+  		/*
+  		 * put the buffer on end of list and if list is empty then
+  		 * assign first and last freebuffer with this buffer id.             
+  		 */     
+  		buf->freeNext = FREENEXT_END_OF_LIST;
+  		if (StrategyControl->firstFreeBuffer < 0)                                
+  		{                
+  			StrategyControl->firstFreeBuffer = buf->buf_id;
+  			StrategyControl->lastFreeBuffer = buf->buf_id;                   
+  			LWLockRelease(BufFreelistLock);              
+  			return;                      
+  		}                                                         
+  		BufferDescriptors[StrategyControl->lastFreeBuffer].freeNext = buf->buf_id;
+  		StrategyControl->lastFreeBuffer = buf->buf_id;
+  	}
+  	LWLockRelease(BufFreelistLock);
+ }                                                                                        
+ 
+ 
+ /*
   * StrategySyncStart -- tell BufferSync where to start syncing
   *
   * The result is the buffer index of the best buffer to sync first.
*** a/src/include/storage/buf_internals.h
--- b/src/include/storage/buf_internals.h
***************
*** 185,190 **** extern BufferDesc *LocalBufferDescriptors;
--- 185,191 ----
  extern volatile BufferDesc *StrategyGetBuffer(BufferAccessStrategy strategy,
  				  bool *lock_held);
  extern void StrategyFreeBuffer(volatile BufferDesc *buf);
+ extern void StrategyMoveBufferToFreeListEnd(volatile BufferDesc *buf);
  extern bool StrategyRejectBuffer(BufferAccessStrategy strategy,
  					 volatile BufferDesc *buf);