mm: use 'unsigned int' for page order

Let's try to be consistent about data type of page order.

[sfr@canb.auug.org.au: fix build (type of pageblock_order)]
[hughd@google.com: some configs end up with MAX_ORDER and pageblock_order having different types]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e361001..208e4c7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -181,7 +181,7 @@
 #endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
-int pageblock_order __read_mostly;
+unsigned int pageblock_order __read_mostly;
 #endif
 
 static void __free_pages_ok(struct page *page, unsigned int order);
@@ -462,7 +462,7 @@
 	__free_pages_ok(page, compound_order(page));
 }
 
-void prep_compound_page(struct page *page, unsigned long order)
+void prep_compound_page(struct page *page, unsigned int order)
 {
 	int i;
 	int nr_pages = 1 << order;
@@ -662,7 +662,7 @@
 	unsigned long combined_idx;
 	unsigned long uninitialized_var(buddy_idx);
 	struct page *buddy;
-	int max_order = MAX_ORDER;
+	unsigned int max_order = MAX_ORDER;
 
 	VM_BUG_ON(!zone_is_initialized(zone));
 	VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
@@ -675,7 +675,7 @@
 		 * pageblock. Without this, pageblock isolation
 		 * could cause incorrect freepage accounting.
 		 */
-		max_order = min(MAX_ORDER, pageblock_order + 1);
+		max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
 	} else {
 		__mod_zone_freepage_state(zone, 1 << order, migratetype);
 	}
@@ -1471,7 +1471,7 @@
 			  int migratetype)
 {
 	struct page *page;
-	unsigned long order;
+	unsigned int order;
 	int pages_moved = 0;
 
 #ifndef CONFIG_HOLES_IN_ZONE
@@ -1584,7 +1584,7 @@
 static void steal_suitable_fallback(struct zone *zone, struct page *page,
 							  int start_type)
 {
-	int current_order = page_order(page);
+	unsigned int current_order = page_order(page);
 	int pages;
 
 	/* Take ownership for orders >= pageblock_order */
@@ -2637,7 +2637,7 @@
 		DEFAULT_RATELIMIT_INTERVAL,
 		DEFAULT_RATELIMIT_BURST);
 
-void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
+void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
 {
 	unsigned int filter = SHOW_MEM_FILTER_NODES;
 
@@ -2671,7 +2671,7 @@
 		va_end(args);
 	}
 
-	pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
+	pr_warn("%s: page allocation failure: order:%u, mode:0x%x\n",
 		current->comm, order, gfp_mask);
 
 	dump_stack();
@@ -3449,7 +3449,8 @@
 	}
 }
 
-static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
+static void *make_alloc_exact(unsigned long addr, unsigned int order,
+		size_t size)
 {
 	if (addr) {
 		unsigned long alloc_end = addr + (PAGE_SIZE << order);
@@ -3499,7 +3500,7 @@
  */
 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
 {
-	unsigned order = get_order(size);
+	unsigned int order = get_order(size);
 	struct page *p = alloc_pages_node(nid, gfp_mask, order);
 	if (!p)
 		return NULL;
@@ -3800,7 +3801,8 @@
 	}
 
 	for_each_populated_zone(zone) {
-		unsigned long nr[MAX_ORDER], flags, order, total = 0;
+		unsigned int order;
+		unsigned long nr[MAX_ORDER], flags, total = 0;
 		unsigned char types[MAX_ORDER];
 
 		if (skip_free_areas_node(filter, zone_to_nid(zone)))
@@ -4149,7 +4151,7 @@
 	nodemask_t used_mask;
 	int local_node, prev_node;
 	struct zonelist *zonelist;
-	int order = current_zonelist_order;
+	unsigned int order = current_zonelist_order;
 
 	/* initialize zonelists */
 	for (i = 0; i < MAX_ZONELISTS; i++) {
@@ -6678,7 +6680,8 @@
 		       unsigned migratetype)
 {
 	unsigned long outer_start, outer_end;
-	int ret = 0, order;
+	unsigned int order;
+	int ret = 0;
 
 	struct compact_control cc = {
 		.nr_migratepages = 0,