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authorVasu Dev <vasu.dev@intel.com>2009-10-23 02:46:33 +0400
committerJames Bottomley <James.Bottomley@suse.de>2009-12-04 21:00:44 +0300
commit4a84067dbfce436b81779e585bf712b02ceee552 (patch)
treef787d413a11c6564ad4440d0a245f56d0e6b73bf /drivers/scsi/scsi_error.c
parent14caf44c69184ed72d46a2f883311daf27a4192f (diff)
downloadlinux-4a84067dbfce436b81779e585bf712b02ceee552.tar.xz
[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_error.c')
-rw-r--r--drivers/scsi/scsi_error.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 7b1e20fee906..08ed506e6059 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -331,6 +331,42 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
}
}
+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 @@ static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
*/
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 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
*/
return ADD_TO_MLQUEUE;
case GOOD:
+ scsi_handle_queue_ramp_up(scmd->device);
case COMMAND_TERMINATED:
return SUCCESS;
case TASK_ABORTED: