*** src/backend/storage/buffer/bufmgr.c~	Tue Jan  1 14:45:51 2008
--- src/backend/storage/buffer/bufmgr.c	Wed Jul  8 18:12:49 2009
***************
*** 1037,1042 ****
--- 1037,1045 ----
  		}
  
  		UnlockBufHdr(bufHdr);
+ 
+ 		if ((buf_id % 256) == 0)
+ 			pg_usleep(1000L);
  	}
  
  	if (num_to_write == 0)