Index: kernel/generic/include/arch.h
===================================================================
--- kernel/generic/include/arch.h	(revision 1066041e4e1803c9b6506af8a869b03669a25957)
+++ kernel/generic/include/arch.h	(revision ee1c2d9cd5399d6bcfa9ffa802a3e8598188074b)
@@ -38,4 +38,5 @@
 #include <arch/arch.h>  /* arch_pre_main() */
 #include <arch/asm.h>   /* get_stack_base() */
+#include <config.h>
 
 
@@ -69,4 +70,7 @@
 typedef struct {
 	size_t preemption;     /**< Preemption disabled counter and flag. */
+#ifdef RCU_PREEMPT_A
+	size_t rcu_nesting;    /**< RCU nesting count and flag. */
+#endif 
 	struct thread *thread; /**< Current thread. */
 	struct task *task;     /**< Current task. */