[SCSI] qla2xxx: Ramp down queue depth for attached SCSI devices when driver resources are low.

Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index a84bb8d6ff74..06c6271d5911 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2536,6 +2536,7 @@ struct req_que {
         srb_t **outstanding_cmds;
         uint32_t current_outstanding_cmd;
         uint16_t num_outstanding_cmds;
+#define MAX_Q_DEPTH             32
         int max_q_depth;
 };
 
@@ -3058,6 +3059,12 @@ struct qla_hw_data {
         struct work_struct idc_state_handler;
         struct work_struct nic_core_unrecoverable;
 
+#define HOST_QUEUE_RAMPDOWN_INTERVAL           (60 * HZ)
+#define HOST_QUEUE_RAMPUP_INTERVAL             (30 * HZ)
+        unsigned long   host_last_rampdown_time;
+        unsigned long   host_last_rampup_time;
+        int             cfg_lun_q_depth;
+
         struct qlt_hw_data tgt;
 };
 
@@ -3117,6 +3124,8 @@ typedef struct scsi_qla_host {
 #define MPI_RESET_NEEDED        19      /* Initiate MPI FW reset */
 #define ISP_QUIESCE_NEEDED      20      /* Driver need some quiescence */
 #define SCR_PENDING             21      /* SCR in target mode */
+#define HOST_RAMP_DOWN_QUEUE_DEPTH     22
+#define HOST_RAMP_UP_QUEUE_DEPTH       23
 
         uint32_t        device_flags;
 #define SWITCH_FOUND            BIT_0