1 files changed, 29 insertions, 39 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9cd36b822444..616a2c956b4b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -467,29 +467,6 @@ static inline void rmv_page_order(struct page *page)
 }
 
 /*
- * Locate the struct page for both the matching buddy in our
- * pair (buddy1) and the combined O(n+1) page they form (page).
- *
- * 1) Any buddy B1 will have an order O twin B2 which satisfies
- * the following equation:
- *     B2 = B1 ^ (1 << O)
- * For example, if the starting buddy (buddy2) is #8 its order
- * 1 buddy is #10:
- *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
- *
- * 2) Any buddy B will have an order O+1 parent P which
- * satisfies the following equation:
- *     P = B & ~(1 << O)
- *
- * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
- */
-static inline unsigned long
-__find_buddy_index(unsigned long page_idx, unsigned int order)
-{
-        return page_idx ^ (1 << order);
-}
-
-/*
  * This function checks whether a page is free && is the buddy
  * we can do coalesce a page and its buddy if
  * (a) the buddy is not in a hole &&
@@ -569,6 +546,7 @@ static inline void __free_one_page(struct page *page,
         unsigned long combined_idx;
         unsigned long uninitialized_var(buddy_idx);
         struct page *buddy;
+        int max_order = MAX_ORDER;
 
         VM_BUG_ON(!zone_is_initialized(zone));
 
@@ -577,13 +555,24 @@ static inline void __free_one_page(struct page *page,
                         return;
 
         VM_BUG_ON(migratetype == -1);
+        if (is_migrate_isolate(migratetype)) {
+                /*
+                 * We restrict max order of merging to prevent merge
+                 * between freepages on isolate pageblock and normal
+                 * pageblock. Without this, pageblock isolation
+                 * could cause incorrect freepage accounting.
+                 */
+                max_order = min(MAX_ORDER, pageblock_order + 1);
+        } else {
+                __mod_zone_freepage_state(zone, 1 << order, migratetype);
+        }
 
-        page_idx = pfn & ((1 << MAX_ORDER) - 1);
+        page_idx = pfn & ((1 << max_order) - 1);
 
         VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
         VM_BUG_ON_PAGE(bad_range(zone, page), page);
 
-        while (order < MAX_ORDER-1) {
+        while (order < max_order - 1) {
                 buddy_idx = __find_buddy_index(page_idx, order);
                 buddy = page + (buddy_idx - page_idx);
                 if (!page_is_buddy(page, buddy, order))
@@ -594,9 +583,11 @@ static inline void __free_one_page(struct page *page,
                  */
                 if (page_is_guard(buddy)) {
                         clear_page_guard_flag(buddy);
-                        set_page_private(page, 0);
-                        __mod_zone_freepage_state(zone, 1 << order,
-                                                  migratetype);
+                        set_page_private(buddy, 0);
+                        if (!is_migrate_isolate(migratetype)) {
+                                __mod_zone_freepage_state(zone, 1 << order,
+                                                          migratetype);
+                        }
                 } else {
                         list_del(&buddy->lru);
                         zone->free_area[order].nr_free--;
@@ -715,14 +706,12 @@ static void free_pcppages_bulk(struct zone *zone, int count,
                         /* must delete as __free_one_page list manipulates */
                         list_del(&page->lru);
                         mt = get_freepage_migratetype(page);
+                        if (unlikely(has_isolate_pageblock(zone)))
+                                mt = get_pageblock_migratetype(page);
+
                         /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
                         __free_one_page(page, page_to_pfn(page), zone, 0, mt);
                         trace_mm_page_pcpu_drain(page, 0, mt);
-                        if (likely(!is_migrate_isolate_page(page))) {
-                                __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
-                                if (is_migrate_cma(mt))
-                                        __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
-                        }
                 } while (--to_free && --batch_free && !list_empty(list));
         }
         spin_unlock(&zone->lock);
@@ -739,9 +728,11 @@ static void free_one_page(struct zone *zone,
         if (nr_scanned)
                 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
 
+        if (unlikely(has_isolate_pageblock(zone) ||
+                is_migrate_isolate(migratetype))) {
+                migratetype = get_pfnblock_migratetype(page, pfn);
+        }
         __free_one_page(page, pfn, zone, order, migratetype);
-        if (unlikely(!is_migrate_isolate(migratetype)))
-                __mod_zone_freepage_state(zone, 1 << order, migratetype);
         spin_unlock(&zone->lock);
 }
 
@@ -1484,7 +1475,7 @@ void split_page(struct page *page, unsigned int order)
 }
 EXPORT_SYMBOL_GPL(split_page);
 
-static int __isolate_free_page(struct page *page, unsigned int order)
+int __isolate_free_page(struct page *page, unsigned int order)
 {
         unsigned long watermark;
         struct zone *zone;
@@ -6408,13 +6399,12 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 
         /* Make sure the range is really isolated. */
         if (test_pages_isolated(outer_start, end, false)) {
-                pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
-                       outer_start, end);
+                pr_info("%s: [%lx, %lx) PFNs busy\n",
+                        __func__, outer_start, end);
                 ret = -EBUSY;
                 goto done;
         }
 
-
         /* Grab isolated pages from freelists. */
         outer_end = isolate_freepages_range(&cc, outer_start, end);
         if (!outer_end) {