; cat x.scm
(define (foo k) (k 123))

(let loop ((i 0))
  (if (< i 1000000)
      (begin
        (call-with-current-continuation
          (lambda (k) (foo k)))
        (loop (+ i 1)))))
; csc x.scm -o a.out
; time ./a.out
0.330u 0.000s 0.321r 	 ./a.out