[PATCH] stop using page.list in the page allocator

Switch the page allocator over to using page.lru for the buddy lists.

mm/page_alloc.c

@@ -199,13 +199,13 @@ static inline void __free_pages_bulk (struct page *page, struct page *base,
 		buddy2 = base + page_idx;
 		BUG_ON(bad_range(zone, buddy1));
 		BUG_ON(bad_range(zone, buddy2));
-		list_del(&buddy1->list);
+		list_del(&buddy1->lru);
 		mask <<= 1;
 		area++;
 		index >>= 1;
 		page_idx &= mask;
 	}
-	list_add(&(base + page_idx)->list, &area->free_list);
+	list_add(&(base + page_idx)->lru, &area->free_list);
 }
 
 static inline void free_pages_check(const char *function, struct page *page)
@@ -253,9 +253,9 @@ free_pages_bulk(struct zone *zone, int count,
 	zone->all_unreclaimable = 0;
 	zone->pages_scanned = 0;
 	while (!list_empty(list) && count--) {
-		page = list_entry(list->prev, struct page, list);
+		page = list_entry(list->prev, struct page, lru);
 		/* have to delete it as __free_pages_bulk list manipulates */
-		list_del(&page->list);
+		list_del(&page->lru);
 		__free_pages_bulk(page, base, zone, area, mask, order);
 		ret++;
 	}
@@ -271,7 +271,7 @@ void __free_pages_ok(struct page *page, unsigned int order)
 	mod_page_state(pgfree, 1 << order);
 	for (i = 0 ; i < (1 << order) ; ++i)
 		free_pages_check(__FUNCTION__, page + i);
-	list_add(&page->list, &list);
+	list_add(&page->lru, &list);
 	kernel_map_pages(page, 1<<order, 0);
 	free_pages_bulk(page_zone(page), 1, &list, order);
 }
@@ -290,7 +290,7 @@ expand(struct zone *zone, struct page *page,
 		area--;
 		high--;
 		size >>= 1;
-		list_add(&page->list, &area->free_list);
+		list_add(&page->lru, &area->free_list);
 		MARK_USED(index, high, area);
 		index += size;
 		page += size;
@@ -353,8 +353,8 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order)
 		if (list_empty(&area->free_list))
 			continue;
 
-		page = list_entry(area->free_list.next, struct page, list);
-		list_del(&page->list);
+		page = list_entry(area->free_list.next, struct page, lru);
+		list_del(&page->lru);
 		index = page - zone->zone_mem_map;
 		if (current_order != MAX_ORDER-1)
 			MARK_USED(index, current_order, area);
@@ -384,7 +384,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
 		if (page == NULL)
 			break;
 		allocated++;
-		list_add_tail(&page->list, list);
+		list_add_tail(&page->lru, list);
 	}
 	spin_unlock_irqrestore(&zone->lock, flags);
 	return allocated;
@@ -426,7 +426,7 @@ int is_head_of_free_region(struct page *page)
 	spin_lock_irqsave(&zone->lock, flags);
 	for (order = MAX_ORDER - 1; order >= 0; --order)
 		list_for_each(curr, &zone->free_area[order].free_list)
-			if (page == list_entry(curr, struct page, list)) {
+			if (page == list_entry(curr, struct page, lru)) {
 				spin_unlock_irqrestore(&zone->lock, flags);
 				return 1 << order;
 			}
@@ -464,7 +464,7 @@ static void fastcall free_hot_cold_page(struct page *page, int cold)
 	local_irq_save(flags);
 	if (pcp->count >= pcp->high)
 		pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
-	list_add(&page->list, &pcp->list);
+	list_add(&page->lru, &pcp->list);
 	pcp->count++;
 	local_irq_restore(flags);
 	put_cpu();
@@ -500,8 +500,8 @@ static struct page *buffered_rmqueue(struct zone *zone, int order, int cold)
 			pcp->count += rmqueue_bulk(zone, 0,
 						pcp->batch, &pcp->list);
 		if (pcp->count) {
-			page = list_entry(pcp->list.next, struct page, list);
-			list_del(&page->list);
+			page = list_entry(pcp->list.next, struct page, lru);
+			list_del(&page->lru);
 			pcp->count--;
 		}
 		local_irq_restore(flags);
@@ -1368,7 +1368,7 @@ void __init memmap_init_zone(struct page *start, unsigned long size, int nid,
 		set_page_zone(page, NODEZONE(nid, zone));
 		set_page_count(page, 0);
 		SetPageReserved(page);
-		INIT_LIST_HEAD(&page->list);
+		INIT_LIST_HEAD(&page->lru);
 #ifdef WANT_PAGE_VIRTUAL
 		/* The shift won't overflow because ZONE_NORMAL is below 4G. */
 		if (zone != ZONE_HIGHMEM)