anchor.diff:  
   (defun initialize-pager ()
     (when (not (boundp '*pager-waiting-threads*))
  -    (setf *pager-noisy* nil
  +    (setf *pager-noisy* t
             *pager-waiting-threads* '()
             *pager-current-thread* nil
             *pager-lock* (place-spinlock-initializer)
  
positive.code:   (assert (>= (+ base length) (* 2 1024 1024 1024)) () "Wired area can't be protected.")
    ;; Implementing this is a litle complicated. It'll need to keep dirty pages in memory.
    ;; Actual possible implementation strategy: Commit if uncommitted, then back write to disk.
    (assert (or (logtest sys.int::+block-map-present+ flags)
                (logtest sys.int::+block-map-zero-fill+ flags))
            () "TODO: Cannot mark block not-present without zero-fill")
    (pager-rpc 'protect-memory-range-in-pager base length flags))
  
  
negative.code:                (with-disk-block (disk-repr block-id)
                   (dotimes (i 512)
                     (let ((entry (sys.int::memref-unsigned-byte-64 disk-repr i)))
                       (when (block-info-present-p entry)
                         (setf (sys.int::memref-signed-byte-64 memory-repr i)
                               (funcall fn (block-info-block-id entry)))))))
                 memory-repr))
             (level-1 (block-id)
               (read-disk-block block-id))
  