Index: /trunk/include/iprt/semaphore.h
===================================================================
--- /trunk/include/iprt/semaphore.h	(revision 42345)
+++ /trunk/include/iprt/semaphore.h	(revision 42346)
@@ -664,4 +664,7 @@
  * they require no syscall if the fast mutex is not held (like critical
  * sections).  Unlike critical sections however, they are *not* recursive.
+ *
+ * @remarks The fast mutexes has sideeffects on IRQL on Windows hosts.  So use
+ *          with care and test on windows with driver verifier.
  *
  * @{ */