Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

[safe/jmp/linux-2.6] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e86965..d79b925 100644 (file)
--- 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();