OS-5192 need faster clock_gettime
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Joshua M. Clulow <jmc@joyent.com>
Reviewed by: Ryan Zezeski <ryan@zinascii.com>

*** 19,28 ****
--- 19,29 ----
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2015 by Delphix. All rights reserved.
+  * Copyright 2016 Joyent, Inc.
   */
  
  /*      Copyright (c) 1988 AT&T */
  /*        All Rights Reserved   */
  
*** 52,61 ****
--- 53,66 ----
  /*
   * Machine dependent parameters and limits.
   */
  
  #if defined(__amd64)
+ /*
+  * If NCPU grows beyond 256, sizing for the x86 comm page will require
+  * adjustment.
+  */
  #define NCPU    256
  #define NCPU_LOG2       8
  #elif defined(__i386)
  #define NCPU    32
  #define NCPU_LOG2       5