mm/debug-pagealloc: prepare boottime configurable on/off

[cascardo/linux.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3b337ef..66560f1 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -19,6 +19,7 @@
 #include <linux/bit_spinlock.h>
 #include <linux/shrinker.h>
 #include <linux/resource.h>
+#include <linux/page_ext.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -2155,20 +2156,36 @@ extern void copy_user_huge_page(struct page *dst, struct page *src,
                                unsigned int pages_per_huge_page);
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
 
+extern struct page_ext_operations debug_guardpage_ops;
+extern struct page_ext_operations page_poisoning_ops;
+
 #ifdef CONFIG_DEBUG_PAGEALLOC
 extern unsigned int _debug_guardpage_minorder;
+extern bool _debug_guardpage_enabled;
 
 static inline unsigned int debug_guardpage_minorder(void)
 {
        return _debug_guardpage_minorder;
 }
 
+static inline bool debug_guardpage_enabled(void)
+{
+       return _debug_guardpage_enabled;
+}
+
 static inline bool page_is_guard(struct page *page)
 {
-       return test_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
+       struct page_ext *page_ext;
+
+       if (!debug_guardpage_enabled())
+               return false;
+
+       page_ext = lookup_page_ext(page);
+       return test_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
 }
 #else
 static inline unsigned int debug_guardpage_minorder(void) { return 0; }
+static inline bool debug_guardpage_enabled(void) { return false; }
 static inline bool page_is_guard(struct page *page) { return false; }
 #endif /* CONFIG_DEBUG_PAGEALLOC */