From 4a84067dbfce436b81779e585bf712b02ceee552 Mon Sep 17 00:00:00 2001 From: Vasu Dev Date: Thu, 22 Oct 2009 15:46:33 -0700 Subject: [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 Tested-by: Christof Schmitt Tested-by: Giridhar Malavali Signed-off-by: James Bottomley 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 0547a7f..50526fa 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 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 @@ 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) { @@ -866,8 +899,12 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev) } /* 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; -- cgit v0.10.2