XXX Rearchitect and replace interrupt distribution

@@ -48,10 +48,11 @@
 #define A_FTRACE        15
 #define A_SWAPCTL       16
 /*                      17-21      reserved for obsolete interface */
 #define A_SDTTEST       22      /* DTrace sdt:::test */
 #define A_CONFIG        23      /* For system configuration */
+#define A_INTRD         24      /* Interrupt balancer */
 
 #define AD_UNKNOWN      -1      /* no method */
 #define AD_HALT         0       /* halt the processor */
 #define AD_BOOT         1       /* multi-user reboot */
 #define AD_IBOOT        2       /* multi-user reboot, ask for name of file */