1 files changed, 28 insertions, 0 deletions
diff --git a/kernel/include/linux/mm.h b/kernel/include/linux/mm.h
index 0755b9fd0..b2085582d 100644
--- a/kernel/include/linux/mm.h
+++ b/kernel/include/linux/mm.h
@@ -1002,6 +1002,34 @@ static inline int page_mapped(struct page *page)
 }
 
 /*
+ * Return true only if the page has been allocated with
+ * ALLOC_NO_WATERMARKS and the low watermark was not
+ * met implying that the system is under some pressure.
+ */
+static inline bool page_is_pfmemalloc(struct page *page)
+{
+	/*
+	 * Page index cannot be this large so this must be
+	 * a pfmemalloc page.
+	 */
+	return page->index == -1UL;
+}
+
+/*
+ * Only to be called by the page allocator on a freshly allocated
+ * page.
+ */
+static inline void set_page_pfmemalloc(struct page *page)
+{
+	page->index = -1UL;
+}
+
+static inline void clear_page_pfmemalloc(struct page *page)
+{
+	page->index = 0;
+}
+
+/*
  * Different kinds of faults, as returned by handle_mm_fault().
  * Used to decide whether a process gets delivered SIGBUS or
  * just gets major/minor fault counters bumped up.