OS-73 do not do IO completions in the ISR
NEX-1889 mpt_sas should support 12G HBAs

          --- old/usr/src/uts/common/io/scsi/adapters/mpt_sas/mpt_sas.conf
          +++ new/usr/src/uts/common/io/scsi/adapters/mpt_sas/mpt_sas.conf

   1    1  #
   2    2  # CDDL HEADER START
   3    3  #
   4    4  # The contents of this file are subject to the terms of the
   5    5  # Common Development and Distribution License (the "License").
   6    6  # You may not use this file except in compliance with the License.
   7    7  #
   8    8  # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9  # or http://www.opensolaris.org/os/licensing.
  10   10  # See the License for the specific language governing permissions
  11   11  # and limitations under the License.
  12   12  #
  13   13  # When distributing Covered Code, include this CDDL HEADER in each
  14   14  # file and include the License file at usr/src/OPENSOLARIS.LICENSE.

  15   15  # If applicable, add the following below this CDDL HEADER, with the
  16   16  # fields enclosed by brackets "[]" replaced with your own identifying
  17   17  # information: Portions Copyright [yyyy] [name of copyright owner]
  18   18  #
  19   19  # CDDL HEADER END
  20   20  #
  21   21  #
  22   22  # Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23   23  # Use is subject to license terms.
  24   24  #
       25 +# Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
  25   26  #
  26   27  
  27   28  #
  28   29  # The mpt_sas driver, as a pHCI driver, must specify the vHCI class it
  29   30  # belongs to(scsi_vhci).
  30   31  #
  31   32  ddi-vhci-class="scsi_vhci";
  32   33  #
  33   34  # I/O multipathing feature (MPxIO) can be enabled or disabled using
  34   35  # mpxio-disable property. Setting mpxio-disable="no" will activate

  35   36  # I/O multipathing; setting mpxio-disable="yes" disables the feature.
  36   37  #
  37   38  # Global mpxio-disable property:
  38   39  #
  39   40  # To globally enable MPxIO on all LSI MPT SAS 2.0/2.5 controllers set:
  40   41  # mpxio-disable="no";
  41   42  #

  42   43  # To globally disable MPxIO on all LSI MPT SAS 2.0/2.5 controllers set:
  43   44  # mpxio-disable="yes";
  44   45  #
  45   46  # You can also enable or disable MPxIO on a per HBA basis. 
  46   47  # Per HBA settings override the global setting for the specified HBAs.
  47   48  # To disable MPxIO on a controller whose parent is /pci@7c0/pci@0/pci@9
  48   49  # and the unit-address is "0" set:
  49   50  # name="mpt_sas" parent="/pci@7c0/pci@0/pci@9" unit-address="0" mpxio-disable="yes";
  50   51  #
  51   52  mpxio-disable="no";
       53 +
       54 +# mpt_sas can do I/O completion in helper threads, reducing the amount
       55 +# of work done within interrupt context.
       56 +#
       57 +# mptsas_doneq_length_threshold_prop specifies the minimum number of
       58 +# I/O completions pending to handle them in a helper thread, a value
       59 +# of 0 causes all I/O completions to be passed to the helper threads.
       60 +mptsas_doneq_length_threshold_prop=0;
    

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