+ /*
+ * The lock_memory_hotplug prevents a race with memory hotplug.
+ * This is a big hammer, a better would be nicer.
+ */
+ lock_memory_hotplug();
+
+ /*
+ * Isolate the page, so that it doesn't get reallocated if it
+ * was free. This flag should be kept set until the source page
+ * is freed and PG_hwpoison on it is set.
+ */
+ if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
+ set_migratetype_isolate(page, true);
+