4781 sd shouldn't abuse ddi_get_time(9f)
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 23,33 ****
   * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
   */
  /*
   * Copyright (c) 2011 Bayard G. Bell.  All rights reserved.
   * Copyright (c) 2012 by Delphix. All rights reserved.
!  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
   * Copyright 2012 DEY Storage Systems, Inc.  All rights reserved.
   */
  /*
   * Copyright 2011 cyril.galibern@opensvc.com
   */
--- 23,33 ----
   * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
   */
  /*
   * Copyright (c) 2011 Bayard G. Bell.  All rights reserved.
   * Copyright (c) 2012 by Delphix. All rights reserved.
!  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
   * Copyright 2012 DEY Storage Systems, Inc.  All rights reserved.
   */
  /*
   * Copyright 2011 cyril.galibern@opensvc.com
   */
*** 6539,6568 ****
   */
  
  static void
  sd_pm_idletimeout_handler(void *arg)
  {
          struct sd_lun *un = arg;
  
-         time_t  now;
- 
          mutex_enter(&sd_detach_mutex);
          if (un->un_detach_count != 0) {
                  /* Abort if the instance is detaching */
                  mutex_exit(&sd_detach_mutex);
                  return;
          }
          mutex_exit(&sd_detach_mutex);
  
-         now = ddi_get_time();
          /*
           * Grab both mutexes, in the proper order, since we're accessing
           * both PM and softstate variables.
           */
          mutex_enter(SD_MUTEX(un));
          mutex_enter(&un->un_pm_mutex);
!         if (((now - un->un_pm_idle_time) > sd_pm_idletime) &&
              (un->un_ncmds_in_driver == 0) && (un->un_pm_count == 0)) {
                  /*
                   * Update the chain types.
                   * This takes affect on the next new command received.
                   */
--- 6539,6566 ----
   */
  
  static void
  sd_pm_idletimeout_handler(void *arg)
  {
+         const hrtime_t idletime = sd_pm_idletime * NANOSEC;
          struct sd_lun *un = arg;
  
          mutex_enter(&sd_detach_mutex);
          if (un->un_detach_count != 0) {
                  /* Abort if the instance is detaching */
                  mutex_exit(&sd_detach_mutex);
                  return;
          }
          mutex_exit(&sd_detach_mutex);
  
          /*
           * Grab both mutexes, in the proper order, since we're accessing
           * both PM and softstate variables.
           */
          mutex_enter(SD_MUTEX(un));
          mutex_enter(&un->un_pm_mutex);
!         if (((gethrtime() - un->un_pm_idle_time) > idletime) &&
              (un->un_ncmds_in_driver == 0) && (un->un_pm_count == 0)) {
                  /*
                   * Update the chain types.
                   * This takes affect on the next new command received.
                   */
*** 12459,12469 ****
                   * This is used for determining if the system has been
                   * idle long enough to make it idle to the PM framework.
                   * This is for lowering the overhead, and therefore improving
                   * performance per I/O operation.
                   */
!                 un->un_pm_idle_time = ddi_get_time();
  
                  un->un_ncmds_in_driver--;
                  ASSERT(un->un_ncmds_in_driver >= 0);
                  SD_INFO(SD_LOG_IO, un,
                      "sd_buf_iodone: un_ncmds_in_driver = %ld\n",
--- 12457,12467 ----
                   * This is used for determining if the system has been
                   * idle long enough to make it idle to the PM framework.
                   * This is for lowering the overhead, and therefore improving
                   * performance per I/O operation.
                   */
!                 un->un_pm_idle_time = gethrtime();
  
                  un->un_ncmds_in_driver--;
                  ASSERT(un->un_ncmds_in_driver >= 0);
                  SD_INFO(SD_LOG_IO, un,
                      "sd_buf_iodone: un_ncmds_in_driver = %ld\n",
*** 12509,12519 ****
           * This is used for determining if the system has been
           * idle long enough to make it idle to the PM framework.
           * This is for lowering the overhead, and therefore improving
           * performance per I/O operation.
           */
!         un->un_pm_idle_time = ddi_get_time();
  
          un->un_ncmds_in_driver--;
          ASSERT(un->un_ncmds_in_driver >= 0);
          SD_INFO(SD_LOG_IO, un, "sd_uscsi_iodone: un_ncmds_in_driver = %ld\n",
              un->un_ncmds_in_driver);
--- 12507,12517 ----
           * This is used for determining if the system has been
           * idle long enough to make it idle to the PM framework.
           * This is for lowering the overhead, and therefore improving
           * performance per I/O operation.
           */
!         un->un_pm_idle_time = gethrtime();
  
          un->un_ncmds_in_driver--;
          ASSERT(un->un_ncmds_in_driver >= 0);
          SD_INFO(SD_LOG_IO, un, "sd_uscsi_iodone: un_ncmds_in_driver = %ld\n",
              un->un_ncmds_in_driver);