1 files changed, 50 insertions, 7 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 74af449b1f1d..998eacc1e4c3 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -48,6 +48,7 @@
 #include <linux/page_cgroup.h>
 #include <linux/debugobjects.h>
 #include <linux/kmemleak.h>
+#include <linux/memory.h>
 #include <trace/events/kmem.h>
 
 #include <asm/tlbflush.h>
@@ -5008,23 +5009,65 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags,
 int set_migratetype_isolate(struct page *page)
 {
         struct zone *zone;
-        unsigned long flags;
+        struct page *curr_page;
+        unsigned long flags, pfn, iter;
+        unsigned long immobile = 0;
+        struct memory_isolate_notify arg;
+        int notifier_ret;
         int ret = -EBUSY;
         int zone_idx;
 
         zone = page_zone(page);
         zone_idx = zone_idx(zone);
+
         spin_lock_irqsave(&zone->lock, flags);
+        if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE ||
+            zone_idx == ZONE_MOVABLE) {
+                ret = 0;
+                goto out;
+        }
+
+        pfn = page_to_pfn(page);
+        arg.start_pfn = pfn;
+        arg.nr_pages = pageblock_nr_pages;
+        arg.pages_found = 0;
+
         /*
-         * In future, more migrate types will be able to be isolation target.
+         * It may be possible to isolate a pageblock even if the
+         * migratetype is not MIGRATE_MOVABLE. The memory isolation
+         * notifier chain is used by balloon drivers to return the
+         * number of pages in a range that are held by the balloon
+         * driver to shrink memory. If all the pages are accounted for
+         * by balloons, are free, or on the LRU, isolation can continue.
+         * Later, for example, when memory hotplug notifier runs, these
+         * pages reported as "can be isolated" should be isolated(freed)
+         * by the balloon driver through the memory notifier chain.
          */
-        if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
-            zone_idx != ZONE_MOVABLE)
+        notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
+        notifier_ret = notifier_to_errno(notifier_ret);
+        if (notifier_ret || !arg.pages_found)
                 goto out;
-        set_pageblock_migratetype(page, MIGRATE_ISOLATE);
-        move_freepages_block(zone, page, MIGRATE_ISOLATE);
-        ret = 0;
+
+        for (iter = pfn; iter < (pfn + pageblock_nr_pages); iter++) {
+                if (!pfn_valid_within(pfn))
+                        continue;
+
+                curr_page = pfn_to_page(iter);
+                if (!page_count(curr_page) || PageLRU(curr_page))
+                        continue;
+
+                immobile++;
+        }
+
+        if (arg.pages_found == immobile)
+                ret = 0;
+
 out:
+        if (!ret) {
+                set_pageblock_migratetype(page, MIGRATE_ISOLATE);
+                move_freepages_block(zone, page, MIGRATE_ISOLATE);
+        }
+
         spin_unlock_irqrestore(&zone->lock, flags);
         if (!ret)
                 drain_all_pages();