2 files changed, 9 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 527ea6382d..579dbaa712 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Dec 20 01:55:03 2010  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* io.c (Init_IO): Added O_DIRECT. This feature was propsed by Run Paint Run Run.
+	  [Feature #4015] [ruby-core:33018]
+
 Sun Dec 19 19:15:23 2010  Tanaka Akira  <akr@fsij.org>
 
 	* marshal.c: parenthesize macro arguments.
diff --git a/io.c b/io.c
index 55d8eb5e16..26ab703eb3 100644
--- a/io.c
+++ b/io.c
@@ -10509,6 +10509,10 @@ Init_IO(void)
     /* do not change atime */
     rb_file_const("NOATIME", INT2FIX(O_NOATIME)); /* Linux */
 #endif
+#ifdef O_DIRECT
+    /*  Try to minimize cache effects of the I/O to and from this file. */
+    rb_file_const("DIRECT", INT2FIX(O_DIRECT));
+#endif
 
     sym_mode = ID2SYM(rb_intern("mode"));
     sym_perm = ID2SYM(rb_intern("perm"));