pg_buffercache_interrupt_check.patch

diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
index ae0291e6e96..5afe4c3765e 100644
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ b/contrib/pg_buffercache/pg_buffercache_pages.c
@@ -193,6 +193,8 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
 		{
 			BufferDesc *bufHdr;
 			uint32		buf_state;
+			
+			CHECK_FOR_INTERRUPTS();
 
 			bufHdr = GetBufferDescriptor(i);
 			/* Lock each buffer header before inspecting. */
@@ -560,6 +562,8 @@ pg_buffercache_summary(PG_FUNCTION_ARGS)
 		BufferDesc *bufHdr;
 		uint32		buf_state;
 
+		CHECK_FOR_INTERRUPTS();
+
 		/*
 		 * This function summarizes the state of all headers. Locking the
 		 * buffer headers wouldn't provide an improved result as the state of
@@ -620,6 +624,8 @@ pg_buffercache_usage_counts(PG_FUNCTION_ARGS)
 		uint32		buf_state = pg_atomic_read_u32(&bufHdr->state);
 		int			usage_count;
 
+		CHECK_FOR_INTERRUPTS();
+
 		usage_count = BUF_STATE_GET_USAGECOUNT(buf_state);
 		usage_counts[usage_count]++;