13902 Fix for 13717 may break 8-disk raidz2
13915 installctx() blocking allocate causes problems
Portions contributed by: Jerry Jelinek <gjelinek@gmail.com>
Change-Id: I934d69946cec42630fc541fa8c7385b862b69ca2

*** 18,28 ****
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
!  * Copyright 2019 Joyent, Inc.
   */
  
  /*
   * x86-specific routines used by the CPU Performance counter driver.
   */
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
!  * Copyright 2021 Joyent, Inc.
   */
  
  /*
   * x86-specific routines used by the CPU Performance counter driver.
   */
*** 167,177 ****
  
          if (kcpc_counts_include_idle)
                  return;
  
          installctx(t, cp, kcpc_idle_save, kcpc_idle_restore,
!             NULL, NULL, NULL, NULL);
  }
  
  void
  kcpc_hw_fini(cpu_t *cp)
  {
--- 167,177 ----
  
          if (kcpc_counts_include_idle)
                  return;
  
          installctx(t, cp, kcpc_idle_save, kcpc_idle_restore,
!             NULL, NULL, NULL, NULL, NULL);
  }
  
  void
  kcpc_hw_fini(cpu_t *cp)
  {