[v6,1/3] export __get_user_pages_fast() function

Commit Message

Xiao Guangrong Aug. 4, 2010, 3:28 a.m. UTC

None

Patch

diff --git a/mm/util.c b/mm/util.c
index f5712e8..4f0d32b 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -250,6 +250,19 @@  void arch_pick_mmap_layout(struct mm_struct *mm)
 }
 #endif
 
+/*
+ * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
+ * back to the regular GUP.
+ * If the architecture not support this fucntion, simply return with no
+ * page pinned
+ */
+int __attribute__((weak)) __get_user_pages_fast(unsigned long start,
+				 int nr_pages, int write, struct page **pages)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__get_user_pages_fast);
+
 /**
  * get_user_pages_fast() - pin user pages in memory
  * @start:	starting user address