The -rt patch includes the following update:
Index: linux/arch/i386/oprofile/Kconfig
===================================================================
--- linux.orig/arch/i386/oprofile/Kconfig
+++ linux/arch/i386/oprofile/Kconfig
@@ -15,3 +15,6 @@ config OPROFILE
If unsure, say N.
+config PROFILE_NMI
+ bool
+ default y
What is the purpose of the PROFILE_NMI config symbol?
(It does not seem to be used anywhere else in the -rt patch.)