memory hotplug: alloc page from other node in memory online

To initialize hotadded node, some pages are allocated.  At that time, the
node hasn't memory, this makes the allocation always fail.  In such case,
let's allocate pages from other nodes.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Yakui Zhao <yakui.zhao@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_cgroup.c

@@ -116,10 +116,16 @@ static int __init_refok init_section_page_cgroup(unsigned long pfn)
 		nid = page_to_nid(pfn_to_page(pfn));
 		table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
 		VM_BUG_ON(!slab_is_available());
-		base = kmalloc_node(table_size,
+		if (node_state(nid, N_HIGH_MEMORY)) {
+			base = kmalloc_node(table_size,
 				GFP_KERNEL | __GFP_NOWARN, nid);
-		if (!base)
-			base = vmalloc_node(table_size, nid);
+			if (!base)
+				base = vmalloc_node(table_size, nid);
+		} else {
+			base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
+			if (!base)
+				base = vmalloc(table_size);
+		}
 	} else {
 		/*
  		 * We don't have to allocate page_cgroup again, but

mm/sparse-vmemmap.c

@@ -48,8 +48,14 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 {
 	/* If the main allocator is up use that, fallback to bootmem. */
 	if (slab_is_available()) {
-		struct page *page = alloc_pages_node(node,
+		struct page *page;
+
+		if (node_state(node, N_HIGH_MEMORY))
+			page = alloc_pages_node(node,
 				GFP_KERNEL | __GFP_ZERO, get_order(size));
+		else
+			page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
+				get_order(size));
 		if (page)
 			return page_address(page);
 		return NULL;

mm/sparse.c

@@ -62,9 +62,12 @@ static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
 	unsigned long array_size = SECTIONS_PER_ROOT *
 				   sizeof(struct mem_section);
 
-	if (slab_is_available())
-		section = kmalloc_node(array_size, GFP_KERNEL, nid);
-	else
+	if (slab_is_available()) {
+		if (node_state(nid, N_HIGH_MEMORY))
+			section = kmalloc_node(array_size, GFP_KERNEL, nid);
+		else
+			section = kmalloc(array_size, GFP_KERNEL);
+	} else
 		section = alloc_bootmem_node(NODE_DATA(nid), array_size);
 
 	if (section)