Index: generic/include/cpu.h
===================================================================
--- generic/include/cpu.h	(revision 6212095a5f8f2d683b1a3e823a12400c54f8efbf)
+++ generic/include/cpu.h	(revision 74fbedb410d3a5939cd2f14e3a15cd2654eb37cf)
@@ -62,4 +62,9 @@
 	link_t timeout_active_head;
 
+	count_t missed_clock_ticks;	/**< When system clock loses a tick, it is recorded here
+					     so that clock() can react. This variable is
+					     CPU-local and can be only accessed when interrupts
+					     are disabled. */
+
 	/**
 	 * Processor ID assigned by kernel.