Merge branch 'akpm' (Andrew's patch-bomb)

Merge misc VM changes from Andrew Morton:
 "The rest of most-of-MM.  The other MM bits await a slab merge.

  This patch includes the addition of a huge zero_page.  Not a
  performance boost but it an save large amounts of physical memory in
  some situations.

  Also a bunch of Fujitsu engineers are working on memory hotplug.
  Which, as it turns out, was badly broken.  About half of their patches
  are included here; the remainder are 3.8 material."

However, this merge disables CONFIG_MOVABLE_NODE, which was totally
broken.  We don't add new features with "default y", nor do we add
Kconfig questions that are incomprehensible to most people without any
help text.  Does the feature even make sense without compaction or
memory hotplug?

* akpm: (54 commits)
  mm/bootmem.c: remove unused wrapper function reserve_bootmem_generic()
  mm/memory.c: remove unused code from do_wp_page()
  asm-generic, mm: pgtable: consolidate zero page helpers
  mm/hugetlb.c: fix warning on freeing hwpoisoned hugepage
  hwpoison, hugetlbfs: fix RSS-counter warning
  hwpoison, hugetlbfs: fix "bad pmd" warning in unmapping hwpoisoned hugepage
  mm: protect against concurrent vma expansion
  memcg: do not check for mm in __mem_cgroup_count_vm_event
  tmpfs: support SEEK_DATA and SEEK_HOLE (reprise)
  mm: provide more accurate estimation of pages occupied by memmap
  fs/buffer.c: remove redundant initialization in alloc_page_buffers()
  fs/buffer.c: do not inline exported function
  writeback: fix a typo in comment
  mm: introduce new field "managed_pages" to struct zone
  mm, oom: remove statically defined arch functions of same name
  mm, oom: remove redundant sleep in pagefault oom handler
  mm, oom: cleanup pagefault oom handler
  memory_hotplug: allow online/offline memory to result movable node
  numa: add CONFIG_MOVABLE_NODE for movable-dedicated node
  mm, memcg: avoid unnecessary function call when memcg is disabled
  ...

1 files changed, 98 insertions, 15 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c3e66ae411fd..518baa896e83 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -106,6 +106,7 @@ static void get_page_bootmem(unsigned long info,  struct page *page,
 void __ref put_page_bootmem(struct page *page)
 {
         unsigned long type;
+        static DEFINE_MUTEX(ppb_lock);
 
         type = (unsigned long) page->lru.next;
         BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
@@ -115,7 +116,14 @@ void __ref put_page_bootmem(struct page *page)
                 ClearPagePrivate(page);
                 set_page_private(page, 0);
                 INIT_LIST_HEAD(&page->lru);
+
+                /*
+                 * Please refer to comment for __free_pages_bootmem()
+                 * for why we serialize here.
+                 */
+                mutex_lock(&ppb_lock);
                 __free_pages_bootmem(page, 0);
+                mutex_unlock(&ppb_lock);
         }
 
 }
@@ -581,11 +589,19 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
         return 0;
 }
 
+#ifdef CONFIG_MOVABLE_NODE
+/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */
+static bool can_online_high_movable(struct zone *zone)
+{
+        return true;
+}
+#else /* #ifdef CONFIG_MOVABLE_NODE */
 /* ensure every online node has NORMAL memory */
 static bool can_online_high_movable(struct zone *zone)
 {
         return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);
 }
+#endif /* #ifdef CONFIG_MOVABLE_NODE */
 
 /* check which state of node_states will be changed when online memory */
 static void node_states_check_changes_online(unsigned long nr_pages,
@@ -595,13 +611,15 @@ static void node_states_check_changes_online(unsigned long nr_pages,
         enum zone_type zone_last = ZONE_NORMAL;
 
         /*
-         * If we have HIGHMEM, node_states[N_NORMAL_MEMORY] contains nodes
-         * which have 0...ZONE_NORMAL, set zone_last to ZONE_NORMAL.
+         * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
+         * contains nodes which have zones of 0...ZONE_NORMAL,
+         * set zone_last to ZONE_NORMAL.
          *
-         * If we don't have HIGHMEM, node_states[N_NORMAL_MEMORY] contains nodes
-         * which have 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
+         * If we don't have HIGHMEM nor movable node,
+         * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
+         * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
          */
-        if (N_HIGH_MEMORY == N_NORMAL_MEMORY)
+        if (N_MEMORY == N_NORMAL_MEMORY)
                 zone_last = ZONE_MOVABLE;
 
         /*
@@ -615,12 +633,34 @@ static void node_states_check_changes_online(unsigned long nr_pages,
         else
                 arg->status_change_nid_normal = -1;
 
+#ifdef CONFIG_HIGHMEM
+        /*
+         * If we have movable node, node_states[N_HIGH_MEMORY]
+         * contains nodes which have zones of 0...ZONE_HIGHMEM,
+         * set zone_last to ZONE_HIGHMEM.
+         *
+         * If we don't have movable node, node_states[N_NORMAL_MEMORY]
+         * contains nodes which have zones of 0...ZONE_MOVABLE,
+         * set zone_last to ZONE_MOVABLE.
+         */
+        zone_last = ZONE_HIGHMEM;
+        if (N_MEMORY == N_HIGH_MEMORY)
+                zone_last = ZONE_MOVABLE;
+
+        if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY))
+                arg->status_change_nid_high = nid;
+        else
+                arg->status_change_nid_high = -1;
+#else
+        arg->status_change_nid_high = arg->status_change_nid_normal;
+#endif
+
         /*
          * if the node don't have memory befor online, we will need to
-         * set the node to node_states[N_HIGH_MEMORY] after the memory
+         * set the node to node_states[N_MEMORY] after the memory
          * is online.
          */
-        if (!node_state(nid, N_HIGH_MEMORY))
+        if (!node_state(nid, N_MEMORY))
                 arg->status_change_nid = nid;
         else
                 arg->status_change_nid = -1;
@@ -631,7 +671,10 @@ static void node_states_set_node(int node, struct memory_notify *arg)
         if (arg->status_change_nid_normal >= 0)
                 node_set_state(node, N_NORMAL_MEMORY);
 
-        node_set_state(node, N_HIGH_MEMORY);
+        if (arg->status_change_nid_high >= 0)
+                node_set_state(node, N_HIGH_MEMORY);
+
+        node_set_state(node, N_MEMORY);
 }
 
 
@@ -713,6 +756,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
                 return ret;
         }
 
+        zone->managed_pages += onlined_pages;
         zone->present_pages += onlined_pages;
         zone->zone_pgdat->node_present_pages += onlined_pages;
         if (onlined_pages) {
@@ -1066,6 +1110,13 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
         return offlined;
 }
 
+#ifdef CONFIG_MOVABLE_NODE
+/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */
+static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
+{
+        return true;
+}
+#else /* #ifdef CONFIG_MOVABLE_NODE */
 /* ensure the node has NORMAL memory if it is still online */
 static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
 {
@@ -1089,6 +1140,7 @@ static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
          */
         return present_pages == 0;
 }
+#endif /* #ifdef CONFIG_MOVABLE_NODE */
 
 /* check which state of node_states will be changed when offline memory */
 static void node_states_check_changes_offline(unsigned long nr_pages,
@@ -1099,13 +1151,15 @@ static void node_states_check_changes_offline(unsigned long nr_pages,
         enum zone_type zt, zone_last = ZONE_NORMAL;
 
         /*
-         * If we have HIGHMEM, node_states[N_NORMAL_MEMORY] contains nodes
-         * which have 0...ZONE_NORMAL, set zone_last to ZONE_NORMAL.
+         * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
+         * contains nodes which have zones of 0...ZONE_NORMAL,
+         * set zone_last to ZONE_NORMAL.
          *
-         * If we don't have HIGHMEM, node_states[N_NORMAL_MEMORY] contains nodes
-         * which have 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
+         * If we don't have HIGHMEM nor movable node,
+         * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
+         * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
          */
-        if (N_HIGH_MEMORY == N_NORMAL_MEMORY)
+        if (N_MEMORY == N_NORMAL_MEMORY)
                 zone_last = ZONE_MOVABLE;
 
         /*
@@ -1122,6 +1176,30 @@ static void node_states_check_changes_offline(unsigned long nr_pages,
         else
                 arg->status_change_nid_normal = -1;
 
+#ifdef CONFIG_HIGHMEM
+        /*
+         * If we have movable node, node_states[N_HIGH_MEMORY]
+         * contains nodes which have zones of 0...ZONE_HIGHMEM,
+         * set zone_last to ZONE_HIGHMEM.
+         *
+         * If we don't have movable node, node_states[N_NORMAL_MEMORY]
+         * contains nodes which have zones of 0...ZONE_MOVABLE,
+         * set zone_last to ZONE_MOVABLE.
+         */
+        zone_last = ZONE_HIGHMEM;
+        if (N_MEMORY == N_HIGH_MEMORY)
+                zone_last = ZONE_MOVABLE;
+
+        for (; zt <= zone_last; zt++)
+                present_pages += pgdat->node_zones[zt].present_pages;
+        if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
+                arg->status_change_nid_high = zone_to_nid(zone);
+        else
+                arg->status_change_nid_high = -1;
+#else
+        arg->status_change_nid_high = arg->status_change_nid_normal;
+#endif
+
         /*
          * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
          */
@@ -1146,9 +1224,13 @@ static void node_states_clear_node(int node, struct memory_notify *arg)
         if (arg->status_change_nid_normal >= 0)
                 node_clear_state(node, N_NORMAL_MEMORY);
 
-        if ((N_HIGH_MEMORY != N_NORMAL_MEMORY) &&
-            (arg->status_change_nid >= 0))
+        if ((N_MEMORY != N_NORMAL_MEMORY) &&
+            (arg->status_change_nid_high >= 0))
                 node_clear_state(node, N_HIGH_MEMORY);
+
+        if ((N_MEMORY != N_HIGH_MEMORY) &&
+            (arg->status_change_nid >= 0))
+                node_clear_state(node, N_MEMORY);
 }
 
 static int __ref __offline_pages(unsigned long start_pfn,
@@ -1248,6 +1330,7 @@ repeat:
         /* reset pagetype flags and makes migrate type to be MOVABLE */
         undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
         /* removal success */
+        zone->managed_pages -= offlined_pages;
         zone->present_pages -= offlined_pages;
         zone->zone_pgdat->node_present_pages -= offlined_pages;
         totalram_pages -= offlined_pages;