memcg: memory hotplug fix for notifier callback

[linux-2.6-omap-h63xx.git] / mm / page_cgroup.c

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 436c00229e703f2d588e5064cb13592b9df014b3..0b3cbf090a674a1424cb1d7cc9e4cd4f3bfa4c02 100644 (file)
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -107,19 +107,29 @@ int __init_refok init_section_page_cgroup(unsigned long pfn)
 
        section = __pfn_to_section(pfn);
 
-       if (section->page_cgroup)
-               return 0;
-
-       nid = page_to_nid(pfn_to_page(pfn));
-
-       table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
-       if (slab_is_available()) {
-               base = kmalloc_node(table_size, GFP_KERNEL, nid);
-               if (!base)
-                       base = vmalloc_node(table_size, nid);
-       } else {
-               base = __alloc_bootmem_node_nopanic(NODE_DATA(nid), table_size,
+       if (!section->page_cgroup) {
+               nid = page_to_nid(pfn_to_page(pfn));
+               table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+               if (slab_is_available()) {
+                       base = kmalloc_node(table_size, GFP_KERNEL, nid);
+                       if (!base)
+                               base = vmalloc_node(table_size, nid);
+               } else {
+                       base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
+                               table_size,
                                PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+               }
+       } else {
+               /*
+                * We don't have to allocate page_cgroup again, but
+                * address of memmap may be changed. So, we have to initialize
+                * again.
+                */
+               base = section->page_cgroup + pfn;
+               table_size = 0;
+               /* check address of memmap is changed or not. */
+               if (base->page == pfn_to_page(pfn))
+                       return 0;
        }
 
        if (!base) {
@@ -208,18 +218,23 @@ static int __meminit page_cgroup_callback(struct notifier_block *self,
                ret = online_page_cgroup(mn->start_pfn,
                                   mn->nr_pages, mn->status_change_nid);
                break;
-       case MEM_CANCEL_ONLINE:
        case MEM_OFFLINE:
                offline_page_cgroup(mn->start_pfn,
                                mn->nr_pages, mn->status_change_nid);
                break;
+       case MEM_CANCEL_ONLINE:
        case MEM_GOING_OFFLINE:
                break;
        case MEM_ONLINE:
        case MEM_CANCEL_OFFLINE:
                break;
        }
-       ret = notifier_from_errno(ret);
+
+       if (ret)
+               ret = notifier_from_errno(ret);
+       else
+               ret = NOTIFY_OK;
+
        return ret;
 }