[SCSI] lpfc 8.1.1 : Added code to adjust lun queue depth to avoid target overloading

Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 1f3873ae9d682b3dfefc36820041a4ddcdd55fa6..38ffa8d6e62901ed94231c45c42571750308e107 100644 (file)
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -29,9 +29,10 @@ struct lpfc_sli2_slim;
 #define LPFC_LC_HBA_Q_DEPTH    1024    /* max cmds per low cost hba */
 #define LPFC_LP101_HBA_Q_DEPTH 128     /* max cmds per low cost hba */
 
-#define LPFC_CMD_PER_LUN       30      /* max outstanding cmds per lun */
+#define LPFC_CMD_PER_LUN       3       /* max outstanding cmds per lun */
 #define LPFC_SG_SEG_CNT                64      /* sg element count per scsi cmnd */
 #define LPFC_IOCB_LIST_CNT     2250    /* list of IOCBs for fast-path usage. */
+#define LPFC_Q_RAMP_UP_INTERVAL 120     /* lun q_depth ramp up interval */
 
 /* Define macros for 64 bit support */
 #define putPaddrLow(addr)    ((uint32_t) (0xffffffff & (u64)(addr)))

diff --git a/drivers/scsi/lpfc/lpfc_disc.h b/drivers/scsi/lpfc/lpfc_disc.h
index 084e7628ce172dc087a41d35b4d678fd7581f860..ed6c81660e03563f94d7720970086e17dd9af08b 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_disc.h
+++ b/drivers/scsi/lpfc/lpfc_disc.h
@@ -73,6 +73,8 @@ struct lpfc_nodelist {
        struct lpfc_hba      *nlp_phba;
        struct lpfc_work_evt nodev_timeout_evt;
        struct lpfc_work_evt els_retry_evt;
+       unsigned long last_ramp_up_time;        /* jiffy of last ramp up */
+       unsigned long last_q_full_time;         /* jiffy of last queue full */
 };
 
 /* Defines for nlp_flag (uint32) */

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index c422220db0ae62cb466d99ddb81bea76488f4a81..9ee8218404c058bc44e40157c891ad6464c2a605 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -409,6 +409,9 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
        struct lpfc_rport_data *rdata = lpfc_cmd->rdata;
        struct lpfc_nodelist *pnode = rdata->pnode;
        struct scsi_cmnd *cmd = lpfc_cmd->pCmd;
+       int result;
+       struct scsi_device *sdev, *tmp_sdev;
+       int depth = 0;
 
        lpfc_cmd->result = pIocbOut->iocb.un.ulpWord[4];
        lpfc_cmd->status = pIocbOut->iocb.ulpStatus;
@@ -460,8 +463,63 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
                                *lp, *(lp + 3), cmd->retries, cmd->resid);
        }
 
+       result = cmd->result;
+       sdev = cmd->device;
        cmd->scsi_done(cmd);
 
+       if (!result &&
+          ((jiffies - pnode->last_ramp_up_time) >
+               LPFC_Q_RAMP_UP_INTERVAL * HZ) &&
+          ((jiffies - pnode->last_q_full_time) >
+               LPFC_Q_RAMP_UP_INTERVAL * HZ) &&
+          (phba->cfg_lun_queue_depth > sdev->queue_depth)) {
+               shost_for_each_device(tmp_sdev, sdev->host) {
+                       if (phba->cfg_lun_queue_depth > tmp_sdev->queue_depth) {
+                               if (tmp_sdev->id != sdev->id)
+                                       continue;
+                               if (tmp_sdev->ordered_tags)
+                                       scsi_adjust_queue_depth(tmp_sdev,
+                                               MSG_ORDERED_TAG,
+                                               tmp_sdev->queue_depth+1);
+                               else
+                                       scsi_adjust_queue_depth(tmp_sdev,
+                                               MSG_SIMPLE_TAG,
+                                               tmp_sdev->queue_depth+1);
+
+                               pnode->last_ramp_up_time = jiffies;
+                       }
+               }
+       }
+
+       /*
+        * Check for queue full.  If the lun is reporting queue full, then
+        * back off the lun queue depth to prevent target overloads.
+        */
+       if (result == SAM_STAT_TASK_SET_FULL) {
+               pnode->last_q_full_time = jiffies;
+
+               shost_for_each_device(tmp_sdev, sdev->host) {
+                       if (tmp_sdev->id != sdev->id)
+                               continue;
+                       depth = scsi_track_queue_full(tmp_sdev,
+                                       tmp_sdev->queue_depth - 1);
+               }
+               /*
+                * The queue depth cannot be lowered any more.
+                * Modify the returned error code to store
+                * the final depth value set by
+                * scsi_track_queue_full.
+                */
+               if (depth == -1)
+                       depth = sdev->host->cmd_per_lun;
+
+               if (depth) {
+                       lpfc_printf_log(phba, KERN_WARNING, LOG_FCP,
+                               "%d:0711 detected queue full - lun queue depth "
+                               " adjusted to %d.\n", phba->brd_no, depth);
+               }
+       }
+
        lpfc_release_scsi_buf(phba, lpfc_cmd);
 }