1 files changed, 52 insertions, 0 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 6cdeabe9f6d4..83d37a401b3b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -164,13 +164,65 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
         return 0;
 }
 
+static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
+{
+        struct pglist_data *pgdat;
+        unsigned long zones_size[MAX_NR_ZONES] = {0};
+        unsigned long zholes_size[MAX_NR_ZONES] = {0};
+        unsigned long start_pfn = start >> PAGE_SHIFT;
+
+        pgdat = arch_alloc_nodedata(nid);
+        if (!pgdat)
+                return NULL;
+
+        arch_refresh_nodedata(nid, pgdat);
+
+        /* we can use NODE_DATA(nid) from here */
+
+        /* init node's zones as empty zones, we don't have any present pages.*/
+        free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
+
+        return pgdat;
+}
+
+static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
+{
+        arch_refresh_nodedata(nid, NULL);
+        arch_free_nodedata(pgdat);
+        return;
+}
+
 int add_memory(int nid, u64 start, u64 size)
 {
+        pg_data_t *pgdat = NULL;
+        int new_pgdat = 0;
         int ret;
 
+        if (!node_online(nid)) {
+                pgdat = hotadd_new_pgdat(nid, start);
+                if (!pgdat)
+                        return -ENOMEM;
+                new_pgdat = 1;
+                ret = kswapd_run(nid);
+                if (ret)
+                        goto error;
+        }
+
         /* call arch's memory hotadd */
         ret = arch_add_memory(nid, start, size);
 
+        if (ret < 0)
+                goto error;
+
+        /* we online node here. we have no error path from here. */
+        node_set_online(nid);
+
+        return ret;
+error:
+        /* rollback pgdat allocation and others */
+        if (new_pgdat)
+                rollback_node_hotadd(nid, pgdat);
+
         return ret;
 }
 EXPORT_SYMBOL_GPL(add_memory);