fix for old kernels which don't have epoll_create1
diff --git a/configure.in b/configure.in
index 95fb8c5..b7eccb7 100644
--- a/configure.in
+++ b/configure.in
@@ -2628,6 +2628,12 @@
    AC_MSG_RESULT(yes)],
   [AC_MSG_RESULT(no)
 ])
+AC_MSG_CHECKING(for epoll_create1)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/epoll.h>]], [[void *x=epoll_create1]])],
+  [AC_DEFINE(HAVE_EPOLL_CREATE1, 1, Define if you have the 'epoll_create1' function.)
+   AC_MSG_RESULT(yes)],
+  [AC_MSG_RESULT(no)
+])
 AC_MSG_CHECKING(for kqueue)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>