Added code to adjust lun queue depth to avoid target overloading.
Signed-off-by: James Smart <James.Smart@xxxxxxxxxx>
diff -upNr a/drivers/scsi/lpfc/lpfc_disc.h b/drivers/scsi/lpfc/lpfc_disc.h
--- a/drivers/scsi/lpfc/lpfc_disc.h 2005-11-28 10:36:16.000000000 -0500
+++ b/drivers/scsi/lpfc/lpfc_disc.h 2005-11-28 11:08:23.000000000 -0500
@@ -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 -upNr a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
--- a/drivers/scsi/lpfc/lpfc.h 2005-11-28 11:06:46.000000000 -0500
+++ b/drivers/scsi/lpfc/lpfc.h 2005-11-28 11:08:23.000000000 -0500
@@ -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 -upNr a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
--- a/drivers/scsi/lpfc/lpfc_scsi.c 2005-11-28 11:06:46.000000000 -0500
+++ b/drivers/scsi/lpfc/lpfc_scsi.c 2005-11-28 11:08:23.000000000 -0500
@@ -409,6 +409,9 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba
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
*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);
}
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