On Thu, Oct 22, 2009 at 03:46:33PM -0700, Vasu Dev wrote:
> 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@xxxxxxxxx>
The patch looks good. I also ran a brief test on s390 again.
Acked-and-tested-by: Christof Schmitt <christof.schmitt@xxxxxxxxxx>
> ---
>
> drivers/scsi/scsi.c | 10 ++++++++--
> drivers/scsi/scsi_error.c | 38 ++++++++++++++++++++++++++++++++++++++
> drivers/scsi/scsi_scan.c | 3 +++
> drivers/scsi/scsi_sysfs.c | 41 +++++++++++++++++++++++++++++++++++++++--
> include/scsi/scsi_device.h | 9 ++++++---
> 5 files changed, 94 insertions(+), 7 deletions(-)
>
> 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 @@ EXPORT_SYMBOL(scsi_adjust_queue_depth);
> */
> 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 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:
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index cb6338f..2847a86 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;
> @@ -940,6 +941,8 @@ 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
> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
> index 4c59336..3a9e805 100644
> --- a/drivers/scsi/scsi_sysfs.c
> +++ b/drivers/scsi/scsi_sysfs.c
> @@ -771,6 +771,8 @@ sdev_store_queue_depth_rw(struct device *dev, struct device_attribute *attr,
> if (retval < 0)
> return retval;
>
> + sdev->max_queue_depth = sdev->queue_depth;
> +
> return count;
> }
>
> @@ -779,6 +781,37 @@ static struct device_attribute sdev_attr_queue_depth_rw =
> 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)
> {
> @@ -870,8 +903,12 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
> get_device(&sdev->sdev_gendev);
>
> /* 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 scsi_device {
> 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;
>
>
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