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authorVasu Dev <vasu.dev@intel.com>2009-10-22 15:46:33 -0700
committerJames Bottomley <James.Bottomley@suse.de>2009-12-04 12:00:44 -0600
commit4a84067dbfce436b81779e585bf712b02ceee552 (patch)
treef787d413a11c6564ad4440d0a245f56d0e6b73bf /drivers/scsi/scsi_scan.c
parent14caf44c69184ed72d46a2f883311daf27a4192f (diff)
downloadblackbird-op-linux-4a84067dbfce436b81779e585bf712b02ceee552.tar.gz
blackbird-op-linux-4a84067dbfce436b81779e585bf712b02ceee552.zip
[SCSI] add queue_depth ramp up code
Current FC HBA queue_depth ramp up code depends on last queue full time. The sdev already has last_queue_full_time field to track last queue full time but stored value is truncated by last four bits. So this patch updates last_queue_full_time without truncating last 4 bits to store full value and then updates its only current usages in scsi_track_queue_full to ignore last four bits to keep current usages same while also use this field in added ramp up code. Adds scsi_handle_queue_ramp_up to ramp up queue_depth on successful completion of IO. The scsi_handle_queue_ramp_up will do ramp up on all luns of a target, just same as ramp down done on all luns on a target. The ramp up is skipped in case the change_queue_depth is not supported by LLD or already reached to added max_queue_depth. Updates added max_queue_depth on every new update to default queue_depth value. The ramp up is also skipped if lapsed time since either last queue ramp up or down is less than LLD specified queue_ramp_up_period. Adds queue_ramp_up_period to sysfs but only if change_queue_depth is supported since ramp up and queue_ramp_up_period is needed only in case change_queue_depth is supported first. Initializes queue_ramp_up_period to 120HZ jiffies as initial default value, it is same as used in existing lpfc and qla2xxx. -v2 Combined all ramp code into this single patch. -v3 Moves max_queue_depth initialization after slave_configure is called from after slave_alloc calling done. Also adjusted max_queue_depth check to skip ramp up if current queue_depth is >= max_queue_depth. -v4 Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f to store or show its value. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com> Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'drivers/scsi/scsi_scan.c')
-rw-r--r--drivers/scsi/scsi_scan.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 0547a7f44d42..50526fa207e5 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -251,6 +251,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
sdev->model = scsi_null_device_strs;
sdev->rev = scsi_null_device_strs;
sdev->host = shost;
+ sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
sdev->id = starget->id;
sdev->lun = lun;
sdev->channel = starget->channel;
@@ -941,6 +942,8 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
}
}
+ sdev->max_queue_depth = sdev->queue_depth;
+
/*
* Ok, the device is now all set up, we can
* register it and tell the rest of the kernel
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