Butenhof on Solaris 1:1 vs M:N

[Daniel Eischen]

I found this interesting take by David Butenhof on Sun's choice of the 1:1
model over the M:N model:

  http://groups.google.com/groups?q=M+x+N+group:comp.programming.threads&hl=en&lr=&ie=UTF-8&oe=UTF-8&scoring=d&selm=3f1e86d9%40usenet01.boi.hp.com&rnum=3

  "Yes, it is hard to get M:N working right, though there are real advantages. 
  (System Software development is not generally dedicated to the principle of 
  avoiding "hard" problems, after all.) But the history of Sun's trouble with 
  M:N isn't nearly as much technical as political. Even when developers tried 
  to address design problems, they weren't allowed. So, yes, giving up on M:N 
  probably was the best course, for Sun. M:N isn't something that can be done 
  halfway -- you either commit to the whole thing and follow through, or 
  you're better off not trying. Unlike Solaris, the Tru64 UNIX M:N scheduling 
  model was actually designed to work, and does. It (like all else) isn't 
  perfect, but it scales, it supports detailed and effective debugging, and 
  it's cleanly and deeply integrated with the kernel."

-- 
Dan Eischen