1 files changed, 40 insertions, 45 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b9a667d36c55..1ad28323fb9f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1188,11 +1188,13 @@ static inline int pageblock_free(struct page *page)
         return PageBuddy(page) && page_order(page) >= pageblock_order;
 }
 
-/* Return the start of the next active pageblock after a given page */
-static struct page *next_active_pageblock(struct page *page)
+/* Return the pfn of the start of the next active pageblock after a given pfn */
+static unsigned long next_active_pageblock(unsigned long pfn)
 {
+        struct page *page = pfn_to_page(pfn);
+
         /* Ensure the starting page is pageblock-aligned */
-        BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
+        BUG_ON(pfn & (pageblock_nr_pages - 1));
 
         /* If the entire pageblock is free, move to the end of free page */
         if (pageblock_free(page)) {
@@ -1200,16 +1202,16 @@ static struct page *next_active_pageblock(struct page *page)
                 /* be careful. we don't have locks, page_order can be changed.*/
                 order = page_order(page);
                 if ((order < MAX_ORDER) && (order >= pageblock_order))
-                        return page + (1 << order);
+                        return pfn + (1 << order);
         }
 
-        return page + pageblock_nr_pages;
+        return pfn + pageblock_nr_pages;
 }
 
-static bool is_pageblock_removable_nolock(struct page *page)
+static bool is_pageblock_removable_nolock(unsigned long pfn)
 {
+        struct page *page = pfn_to_page(pfn);
         struct zone *zone;
-        unsigned long pfn;
 
         /*
          * We have to be careful here because we are iterating over memory
@@ -1232,12 +1234,14 @@ static bool is_pageblock_removable_nolock(struct page *page)
 /* Checks if this range of memory is likely to be hot-removable. */
 bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
 {
-        struct page *page = pfn_to_page(start_pfn);
-        struct page *end_page = page + nr_pages;
+        unsigned long end_pfn, pfn;
+
+        end_pfn = min(start_pfn + nr_pages,
+                        zone_end_pfn(page_zone(pfn_to_page(start_pfn))));
 
         /* Check the starting page of each pageblock within the range */
-        for (; page < end_page; page = next_active_pageblock(page)) {
-                if (!is_pageblock_removable_nolock(page))
+        for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) {
+                if (!is_pageblock_removable_nolock(pfn))
                         return false;
                 cond_resched();
         }
@@ -1273,6 +1277,9 @@ int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
                                 i++;
                         if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn)
                                 continue;
+                        /* Check if we got outside of the zone */
+                        if (zone && !zone_spans_pfn(zone, pfn + i))
+                                return 0;
                         page = pfn_to_page(pfn + i);
                         if (zone && page_zone(page) != zone)
                                 return 0;
@@ -1301,23 +1308,27 @@ int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
 static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
 {
         unsigned long pfn;
-        struct page *page;
+
         for (pfn = start; pfn < end; pfn++) {
-                if (pfn_valid(pfn)) {
-                        page = pfn_to_page(pfn);
-                        if (PageLRU(page))
-                                return pfn;
-                        if (__PageMovable(page))
-                                return pfn;
-                        if (PageHuge(page)) {
-                                if (hugepage_migration_supported(page_hstate(page)) &&
-                                    page_huge_active(page))
-                                        return pfn;
-                                else
-                                        pfn = round_up(pfn + 1,
-                                                1 << compound_order(page)) - 1;
-                        }
-                }
+                struct page *page, *head;
+                unsigned long skip;
+
+                if (!pfn_valid(pfn))
+                        continue;
+                page = pfn_to_page(pfn);
+                if (PageLRU(page))
+                        return pfn;
+                if (__PageMovable(page))
+                        return pfn;
+
+                if (!PageHuge(page))
+                        continue;
+                head = compound_head(page);
+                if (hugepage_migration_supported(page_hstate(head)) &&
+                    page_huge_active(head))
+                        return pfn;
+                skip = (1 << compound_order(head)) - (page - head);
+                pfn += skip - 1;
         }
         return 0;
 }
@@ -1344,7 +1355,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 {
         unsigned long pfn;
         struct page *page;
-        int not_managed = 0;
         int ret = 0;
         LIST_HEAD(source);
 
@@ -1392,7 +1402,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
                 else
                         ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
                 if (!ret) { /* Success */
-                        put_page(page);
                         list_add_tail(&page->lru, &source);
                         if (!__PageMovable(page))
                                 inc_node_page_state(page, NR_ISOLATED_ANON +
@@ -1401,22 +1410,10 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
                 } else {
                         pr_warn("failed to isolate pfn %lx\n", pfn);
                         dump_page(page, "isolation failed");
-                        put_page(page);
-                        /* Because we don't have big zone->lock. we should
-                           check this again here. */
-                        if (page_count(page)) {
-                                not_managed++;
-                                ret = -EBUSY;
-                                break;
-                        }
                 }
+                put_page(page);
         }
         if (!list_empty(&source)) {
-                if (not_managed) {
-                        putback_movable_pages(&source);
-                        goto out;
-                }
-
                 /* Allocate a new page from the nearest neighbor node */
                 ret = migrate_pages(&source, new_node_page, NULL, 0,
                                         MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
@@ -1429,7 +1426,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
                         putback_movable_pages(&source);
                 }
         }
-out:
+
         return ret;
 }
 
@@ -1576,7 +1573,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
            we assume this for now. .*/
         if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start,
                                   &valid_end)) {
-                mem_hotplug_done();
                 ret = -EINVAL;
                 reason = "multizone range";
                 goto failed_removal;
@@ -1591,7 +1587,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
                                        MIGRATE_MOVABLE,
                                        SKIP_HWPOISON | REPORT_FAILURE);
         if (ret) {
-                mem_hotplug_done();
                 reason = "failure to isolate range";
                 goto failed_removal;
         }