Index: kern/subr_param.c
===================================================================
--- kern/subr_param.c	(revision 245047)
+++ kern/subr_param.c	(working copy)
@@ -333,7 +333,7 @@
 	 * At most it can be 3/4 of available kernel memory.
 	 */
 	realmem = qmin((quad_t)physpages * PAGE_SIZE,
-	    VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS);
+	    virtual_end - virtual_avail);
 	maxmbufmem = realmem / 2;
 	TUNABLE_QUAD_FETCH("kern.maxmbufmem", &maxmbufmem);
 	if (maxmbufmem > (realmem / 4) * 3)
@@ -347,8 +347,8 @@
 	TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
 	if (maxpipekva < 512 * 1024)
 		maxpipekva = 512 * 1024;
-	if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64)
-		maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
+	if (maxpipekva > (virtual_end - virtual_avail) / 64)
+		maxpipekva = (virtual_end - virtual_avail) /
 		    64;
 }