OS-6363 system went to dark side of moon for ~467 seconds OS-6404 ARC reclaim should throttle its calls to arc_kmem_reap_now() Reviewed by: Bryan Cantrill <bryan@joyent.com> Reviewed by: Dan McDonald <danmcd@joyent.com>

*** 23,33 ****
   * Use is subject to license terms.
   */
  
  /*
   * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
!  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
   */
  
  /*
   * Big Theory Statement for the virtual memory allocator.
   *
--- 23,33 ----
   * Use is subject to license terms.
   */
  
  /*
   * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
!  * Copyright (c) 2017, Joyent, Inc.
   */
  
  /*
   * Big Theory Statement for the virtual memory allocator.
   *
*** 1743,1753 ****
          /*
           * Reap any quantum caches that may be part of this vmem.
           */
          for (i = 0; i < VMEM_NQCACHE_MAX; i++)
                  if (vmp->vm_qcache[i])
!                         kmem_cache_reap_now(vmp->vm_qcache[i]);
  }
  
  /*
   * Prepare vmem for use.
   */
--- 1743,1753 ----
          /*
           * Reap any quantum caches that may be part of this vmem.
           */
          for (i = 0; i < VMEM_NQCACHE_MAX; i++)
                  if (vmp->vm_qcache[i])
!                         kmem_cache_reap_soon(vmp->vm_qcache[i]);
  }
  
  /*
   * Prepare vmem for use.
   */