--- src/sys/kern/kern_subr.c	2004/10/25 19:14:32	1.19
+++ src/sys/kern/kern_subr.c	2004/11/09 17:52:45	1.20
@@ -49,6 +49,8 @@
 #include <sys/malloc.h>
 #include <sys/lock.h>
 #include <sys/resourcevar.h>
+#include <sys/sysctl.h>
+#include <sys/uio.h>
 #include <sys/vnode.h>
 #include <machine/limits.h>
 
@@ -56,6 +58,9 @@
 #include <vm/vm_page.h>
 #include <vm/vm_map.h>
 
+SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, NULL, UIO_MAXIOV,
+	"Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");
+
 /*
  * UIO_READ:	copy the kernelspace cp to the user or kernelspace UIO
  * UIO_WRITE:	copy the user or kernelspace UIO to cp