diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 8b3983988a484eb8774e10bbd9a35837e3cb2429..591906bb6cdde346268ee6f6b50ab985d7073b73 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -1065,6 +1065,21 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 	walRecord.cap = 0;
 	walRecord.buf = NULL;
 	walRecord.count = 0;
+
+	/* for read page precache, not only new extend page*/
+	if (*preCacheNodesCountPtr > 0)
+	{
+		uint16 preCacheNodei = 0;
+		while (preCacheNodei < *preCacheNodesCountPtr)
+		{
+			if (preCacheNodesPtr[preCacheNodei] == bufHdr->tag.rnode.relNode)
+			{
+				bufHdr->isPreCacheEscape=true;
+				break;
+			}
+			preCacheNodei++;
+		}
+	}
 	 
 	if (isExtend)
 	{
@@ -1075,21 +1090,6 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 		
 		/* don't set checksum for all-zero page */
 
-		/* for new page precache */
-		if (*preCacheNodesCountPtr > 0)
-		{
-			uint16 preCacheNodei = 0;
-			while (preCacheNodei < *preCacheNodesCountPtr)
-			{
-				if (preCacheNodesPtr[preCacheNodei] == bufHdr->tag.rnode.relNode)
-				{
-					bufHdr->isPreCacheEscape=true;
-					break;
-				}
-				preCacheNodei++;
-			}
-		}
-
 		/*
 		 * NB: we're *not* doing a ScheduleBufferTagForWriteback here;
 		 * although we're essentially performing a write. At least on linux
@@ -1528,7 +1528,8 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 		 * won't prevent hint-bit updates).  We will recheck the dirty bit
 		 * after re-locking the buffer header.
 		 */
-		if (oldFlags & BM_DIRTY)
+		
+		if ((oldFlags & BM_DIRTY) || (buf->isPreCacheEscape == true && !IsMetaExist(buf->tag.rnode.dbNode,buf->tag.rnode.relNode,buf->tag.forkNum,buf->tag.blockNum)))
 		{
 			/*
 			 * We need a share-lock on the buffer contents to write it out
@@ -1583,10 +1584,18 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 				/* he3db: FlushBuffer to He3DBFlushBuffer*/
 				// if (push_standby == true) {
 				// master/slave/push standby need to flush dirty page to release space
-					FlushBuffer(buf, NULL,0);
+					//FlushBuffer(buf, NULL,0);
 				// } else {
 				// 	He3DBFlushBuffer(buf, NULL);
 				// }
+				if ((oldFlags & BM_DIRTY) && buf->isPreCacheEscape == false)
+				{
+					FlushBuffer(buf, NULL,0);
+				}
+				else
+				{
+					FlushBuffer(buf, NULL,1);
+				}
 
 				LWLockRelease(BufferDescriptorGetContentLock(buf));
 
diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c
index 62f2a80adc8766fc07d4fbe1230b8a1c7c340b2b..229385862c5b5a9768089bbde4ed688f64570d1b 100644
--- a/src/backend/storage/buffer/freelist.c
+++ b/src/backend/storage/buffer/freelist.c
@@ -204,6 +204,7 @@ StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
 	int			bgwprocno;
 	int			trycounter;
 	uint32		local_buf_state;	/* to avoid repeated (de-)referencing */
+	bool		secondring;
 
 	/*
 	 * If given a strategy object, see whether it can select a buffer. We
@@ -314,6 +315,7 @@ StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
 
 	/* Nothing on the freelist, so run the "clock sweep" algorithm */
 	trycounter = NBuffers;
+	secondring = false;
 	for (;;)
 	{
 		buf = GetBufferDescriptor(ClockSweepTick());
@@ -324,7 +326,7 @@ StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
 		 */
 		local_buf_state = LockBufHdr(buf);
 
-		if (buf->isPreCacheEscape == false && BUF_STATE_GET_REFCOUNT(local_buf_state) == 0)
+		if (((buf->isPreCacheEscape == false && !secondring) || (buf->isPreCacheEscape == true && secondring)) && BUF_STATE_GET_REFCOUNT(local_buf_state) == 0)
 		{
 			if (BUF_STATE_GET_USAGECOUNT(local_buf_state) != 0)
 			{
@@ -351,7 +353,12 @@ StrategyGetBuffer(BufferAccessStrategy strategy, uint32 *buf_state)
 			 * infinite loop.
 			 */
 			UnlockBufHdr(buf, local_buf_state);
-			elog(ERROR, "no unpinned buffers available");
+			if (*preCacheNodesCountPtr == 0 || secondring)
+			{
+				elog(ERROR, "no unpinned buffers available");
+			}
+			secondring = true;
+			trycounter = NBuffers;
 		}
 		UnlockBufHdr(buf, local_buf_state);
 	}