[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.c b/drivers/scsi/scsi.c
index dd098ca..a60da55 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -940,10 +940,16 @@
*/
int scsi_track_queue_full(struct scsi_device *sdev, int depth)
{
- if ((jiffies >> 4) == sdev->last_queue_full_time)
+
+ /*
+ * Don't let QUEUE_FULLs on the same
+ * jiffies count, they could all be from
+ * same event.
+ */
+ if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
return 0;
- sdev->last_queue_full_time = (jiffies >> 4);
+ sdev->last_queue_full_time = jiffies;
if (sdev->last_queue_full_depth != depth) {
sdev->last_queue_full_count = 1;
sdev->last_queue_full_depth = depth;
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 7b1e20f..08ed506 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -331,6 +331,42 @@
}
}
+static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
+{
+ struct scsi_host_template *sht = sdev->host->hostt;
+ struct scsi_device *tmp_sdev;
+
+ if (!sht->change_queue_depth ||
+ sdev->queue_depth >= sdev->max_queue_depth)
+ return;
+
+ if (time_before(jiffies,
+ sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
+ return;
+
+ if (time_before(jiffies,
+ sdev->last_queue_full_time + sdev->queue_ramp_up_period))
+ return;
+
+ /*
+ * Walk all devices of a target and do
+ * ramp up on them.
+ */
+ shost_for_each_device(tmp_sdev, sdev->host) {
+ if (tmp_sdev->channel != sdev->channel ||
+ tmp_sdev->id != sdev->id ||
+ tmp_sdev->queue_depth == sdev->max_queue_depth)
+ continue;
+ /*
+ * call back into LLD to increase queue_depth by one
+ * with ramp up reason code.
+ */
+ sht->change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1,
+ SCSI_QDEPTH_RAMP_UP);
+ sdev->last_queue_ramp_up = jiffies;
+ }
+}
+
static void scsi_handle_queue_full(struct scsi_device *sdev)
{
struct scsi_host_template *sht = sdev->host->hostt;
@@ -393,6 +429,7 @@
*/
switch (status_byte(scmd->result)) {
case GOOD:
+ scsi_handle_queue_ramp_up(scmd->device);
case COMMAND_TERMINATED:
return SUCCESS;
case CHECK_CONDITION:
@@ -1425,6 +1462,7 @@
*/
return ADD_TO_MLQUEUE;
case GOOD:
+ scsi_handle_queue_ramp_up(scmd->device);
case COMMAND_TERMINATED:
return SUCCESS;
case TASK_ABORTED:
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 0547a7f..50526fa 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -251,6 +251,7 @@
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 @@
}
}
+ 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
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) {
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 9af48cb..92c4c3b 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -81,11 +81,14 @@
struct list_head starved_entry;
struct scsi_cmnd *current_cmnd; /* currently active command */
unsigned short queue_depth; /* How deep of a queue we want */
+ unsigned short max_queue_depth; /* max queue depth */
unsigned short last_queue_full_depth; /* These two are used by */
unsigned short last_queue_full_count; /* scsi_track_queue_full() */
- unsigned long last_queue_full_time;/* don't let QUEUE_FULLs on the same
- jiffie count on our counter, they
- could all be from the same event. */
+ unsigned long last_queue_full_time; /* last queue full time */
+ unsigned long queue_ramp_up_period; /* ramp up period in jiffies */
+#define SCSI_DEFAULT_RAMP_UP_PERIOD (120 * HZ)
+
+ unsigned long last_queue_ramp_up; /* last queue ramp up time */
unsigned int id, lun, channel;
