diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 3721f8d..5652569 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -234,6 +234,17 @@
 	 * (i.e. memory-hot-remove function)
 	 */
 	list_for_each_entry(info, &mem_device->res_list, list) {
+		u64 start_pfn, end_pfn;
+
+		start_pfn = info->start_addr >> PAGE_SHIFT;
+		end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
+
+		if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
+			/* already enabled. try next area */
+			num_enabled++;
+			continue;
+		}
+
 		result = add_memory(info->start_addr, info->length);
 		if (result)
 			continue;