return atomic_read(&(page)->_mapcount) >= 0;
}
+/*
+ * 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