title: Increasing Stack Space
body: <p>When I run the following code: </p>
  
  <pre><code>(defun countdown (n)
    (if (&gt;= n 0)
      (cons n (countdown (- n 1)))))
  
  (countdown 100000)
  </code></pre>
  
  <p>I get the following message : </p>
  
  <pre><code>INFO: Control stack guard page unprotected
  Control stack guard page temporarily disabled: proceed with caution
  
  debugger invoked on a SB-KERNEL::CONTROL-STACK-EXHAUSTED in thread
  #&lt;THREAD "main thread" RUNNING {1002B03653}&gt;:
    Control stack exhausted (no more space for function call frames).
  This is probably due to heavily nested or infinitely recursive function
  calls, or a tail call that SBCL cannot or has not optimized away.
  
  PROCEED WITH CAUTION.
  
  Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.
  
  restarts (invokable by number or by possibly-abbreviated name):
    0: [ABORT] Exit debugger, returning to top level.
  
  (SB-KERNEL::CONTROL-STACK-EXHAUSTED-ERROR)
  </code></pre>
  
  <p><strong>How do I increase the stack space?</strong> I do not want to change the code above; I supplied it purely to illustrate stack exhaustion.</p>