[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>
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index a487828..758598f 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -771,6 +771,8 @@
if (retval < 0)
return retval;
+ sdev->max_queue_depth = sdev->queue_depth;
+
return count;
}
@@ -779,6 +781,37 @@
sdev_store_queue_depth_rw);
static ssize_t
+sdev_show_queue_ramp_up_period(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev;
+ sdev = to_scsi_device(dev);
+ return snprintf(buf, 20, "%u\n",
+ jiffies_to_msecs(sdev->queue_ramp_up_period));
+}
+
+static ssize_t
+sdev_store_queue_ramp_up_period(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ unsigned long period;
+
+ if (strict_strtoul(buf, 10, &period))
+ return -EINVAL;
+
+ sdev->queue_ramp_up_period = msecs_to_jiffies(period);
+ return period;
+}
+
+static struct device_attribute sdev_attr_queue_ramp_up_period =
+ __ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR,
+ sdev_show_queue_ramp_up_period,
+ sdev_store_queue_ramp_up_period);
+
+static ssize_t
sdev_store_queue_type_rw(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -866,8 +899,12 @@
}
/* create queue files, which may be writable, depending on the host */
- if (sdev->host->hostt->change_queue_depth)
- error = device_create_file(&sdev->sdev_gendev, &sdev_attr_queue_depth_rw);
+ if (sdev->host->hostt->change_queue_depth) {
+ error = device_create_file(&sdev->sdev_gendev,
+ &sdev_attr_queue_depth_rw);
+ error = device_create_file(&sdev->sdev_gendev,
+ &sdev_attr_queue_ramp_up_period);
+ }
else
error = device_create_file(&sdev->sdev_gendev, &dev_attr_queue_depth);
if (error) {
