diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7c06581..40fca1b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2592,7 +2592,7 @@ extern int get_hwpoison_page(struct page *page);
 extern int sysctl_memory_failure_early_kill;
 extern int sysctl_memory_failure_recovery;
 extern void shake_page(struct page *p, int access);
-extern atomic_long_t num_poisoned_pages;
+extern atomic_long_t num_poisoned_pages __read_mostly;
 extern int soft_offline_page(struct page *page, int flags);