panic: vm_proc_new: upage allocation failed (5.6-BETA6)

PAE still panics on boot, GENERIC still works flawlessly save 4G of RAM.

(kgdb) where
#0  kdb_enter (msg=???) at /usr/src/sys/kern/subr_kdb.c:241
#1  0xc039e3c7 in panic (fmt=0xc0564ae2 "vm_proc_new: upage allocation failed")
    at /usr/src/sys/kern/kern_shutdown.c:537
#2  0xc04c1a68 in vm_proc_new (p=0xca86ba80) at /usr/src/sys/vm/vm_glue.c:255
#3  0xc0396add in proc_init (mem=0xca86ba80, size=448, flags=259)
    at /usr/src/sys/kern/kern_proc.c:182
#4  0xc04d33f5 in slab_zalloc (zone=0xc0a232c0, wait=259)
    at /usr/src/sys/vm/uma_core.c:839
#5  0xc04d4a18 in uma_zone_slab (zone=0xc0a232c0, flags=3)
    at /usr/src/sys/vm/uma_core.c:1959
#6  0xc04d4c2c in uma_zalloc_bucket (zone=0xc0a232c0, flags=3)
    at /usr/src/sys/vm/uma_core.c:2062
#7  0xc04d48c2 in uma_zalloc_arg (zone=0xc0a232c0, udata=0x0, flags=2)
    at /usr/src/sys/vm/uma_core.c:1886
#8  0xc038765f in fork1 (td=0xc05d9fc0, flags=131124, pages=0,
    procp=0xc087fd50) at uma.h:274
#9  0xc038dafd in kthread_create (func=0xc04d14bc <vm_pageout>, arg=0x0,
    newpp=0xc05f2d98, flags=0, pages=0, fmt=0xc0536614 "%s")
    at /usr/src/sys/kern/kern_kthread.c:86
#10 0xc038daa3 in kproc_start (udata=0xc05c7840)
    at /usr/src/sys/kern/kern_kthread.c:58
#11 0xc03761f2 in mi_startup () at /usr/src/sys/kern/init_main.c:210
#12 0xc024113e in begin () at /usr/src/sys/i386/i386/locore.s:348