src/patches/suse-2.6.27.39/patches.fixes/zfcp-make-queue_depth-adjustable

   1 From: Christof Schmitt <christof.schmitt@de.ibm.com>
   2 Subject: [SCSI] zfcp: Make queue_depth adjustable
   3 Patch-mainline: 2.6.31-rc1
   4 Git-commit: a40a1bafe7da0afe61b1c20fc50e18c07ce724f9
   5 References: bnc#513954
   6
   7 [SCSI] zfcp: Make queue_depth adjustable
   8
   9 zfcp did always set the queue_depth for SCSI devices to 32, not
  10 allowing to change this. Introduce a kernel parameter zfcp.queue_depth
  11 and the change_queue_depth callback to allow changing the queue_depth
  12 when it is required.
  13
  14 Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
  15 Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
  16 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
  17 Acked-by: Jeff Mahoney <jeffm@suse.com>
  18 ---
  19  drivers/s390/scsi/zfcp_scsi.c |   13 ++++++++++++-
  20  1 file changed, 12 insertions(+), 1 deletion(-)
  21
  22 --- a/drivers/s390/scsi/zfcp_scsi.c
  23 +++ b/drivers/s390/scsi/zfcp_scsi.c
  24 @@ -11,6 +11,10 @@
  25  #include "zfcp_ext.h"
  26  #include <asm/atomic.h>
  27
  28 +static unsigned int default_depth = 32;
  29 +module_param_named(queue_depth, default_depth, uint, 0600);
  30 +MODULE_PARM_DESC(queue_depth, "Default queue depth for new SCSI devices");
  31 +
  32  /* Find start of Sense Information in FCP response unit*/
  33  char *zfcp_get_fcp_sns_info_ptr(struct fcp_rsp_iu *fcp_rsp_iu)
  34  {
  35 @@ -23,6 +27,12 @@ char *zfcp_get_fcp_sns_info_ptr(struct f
  36         return fcp_sns_info_ptr;
  37  }
  38
  39 +static int zfcp_scsi_change_queue_depth(struct scsi_device *sdev, int depth)
  40 +{
  41 +       scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
  42 +       return sdev->queue_depth;
  43 +}
  44 +
  45  static void zfcp_scsi_slave_destroy(struct scsi_device *sdpnt)
  46  {
  47         struct zfcp_unit *unit = (struct zfcp_unit *) sdpnt->hostdata;
  48 @@ -34,7 +44,7 @@ static void zfcp_scsi_slave_destroy(stru
  49  static int zfcp_scsi_slave_configure(struct scsi_device *sdp)
  50  {
  51         if (sdp->tagged_supported)
  52 -               scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, 32);
  53 +               scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, default_depth);
  54         else
  55                 scsi_adjust_queue_depth(sdp, 0, 1);
  56         return 0;
  57 @@ -653,6 +663,7 @@ struct zfcp_data zfcp_data = {
  58                 .name                    = "zfcp",
  59                 .module                  = THIS_MODULE,
  60                 .proc_name               = "zfcp",
  61 +               .change_queue_depth      = zfcp_scsi_change_queue_depth,
  62                 .slave_alloc             = zfcp_scsi_slave_alloc,
  63                 .slave_configure         = zfcp_scsi_slave_configure,
  64                 .slave_destroy           = zfcp_scsi_slave_destroy,