+bool _debug_pagealloc_enabled __read_mostly;
+bool _debug_guardpage_enabled __read_mostly;
+
+static int __init early_debug_pagealloc(char *buf)
+{
+ if (!buf)
+ return -EINVAL;
+
+ if (strcmp(buf, "on") == 0)
+ _debug_pagealloc_enabled = true;
+
+ return 0;
+}
+early_param("debug_pagealloc", early_debug_pagealloc);
+
+static bool need_debug_guardpage(void)
+{
+ /* If we don't use debug_pagealloc, we don't need guard page */
+ if (!debug_pagealloc_enabled())
+ return false;
+
+ return true;
+}
+
+static void init_debug_guardpage(void)
+{
+ if (!debug_pagealloc_enabled())
+ return;
+
+ _debug_guardpage_enabled = true;
+}
+
+struct page_ext_operations debug_guardpage_ops = {
+ .need = need_debug_guardpage,
+ .init = init_debug_guardpage,
+};