page-allocator: clear N_HIGH_MEMORY map before we set it again

SRAT tables may contains nodes of very small size.  The arch code may
decide to not activate such a node.  However, currently the early boot
code sets N_HIGH_MEMORY for such nodes.  These nodes therefore seem to be
active although these nodes have no present pages.

For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too

Signed-off-by: Yinghai Lu <Yinghai@kernel.org>
Tested-by: Jack Steiner <steiner@sgi.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

@@ -4204,6 +4204,11 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
 						early_node_map[i].start_pfn,
 						early_node_map[i].end_pfn);
 
+	/*
+	 * find_zone_movable_pfns_for_nodes/early_calculate_totalpages init
+	 * that node_mask, clear it at first
+	 */
+	nodes_clear(node_states[N_HIGH_MEMORY]);
 	/* Initialise every node */
 	mminit_verify_pageflags_layout();
 	setup_nr_node_ids();