diff -r bd86485d966a -r 64fe22ca6e6f config/libc.in
--- a/config/libc.in	Sun Dec 12 22:18:52 2010 +0100
+++ b/config/libc.in	Fri Nov 18 11:32:50 2011 +0800
@@ -23,26 +23,21 @@
 
 config LIBC_SUPPORT_THREADS_ANY
     bool
-    default n
 
 config LIBC_SUPPORT_NPTL
     bool
-    default n
     select LIBC_SUPPORT_THREADS_ANY
 
 config LIBC_SUPPORT_LINUXTHREADS
     bool
-    default n
     select LIBC_SUPPORT_THREADS_ANY
 
 config LIBC_SUPPORT_WIN32THREADS
     bool
-    default n
     select LIBC_SUPPORT_THREADS_ANY
 
 config LIBC_SUPPORT_THREADS_NONE
     bool
-    default n
 
 config THREADS
     string