target: Add counters for ABORT_TASK success + failure

This patch introduces two counters for ABORT_TASK success +
failure under:

   /sys/kernel/config/target/core/$HBA/$DEV/statistics/scsi_tgt_dev/

that are useful for diagnosing various backend device latency
and front fabric issues.

Normally when folks see alot of aborts_complete happening,
it means the backend device I/O completion latency is high,
and not returning completions fast enough before host side
timeouts trigger.

And normally when folks see alot of aborts_no_task, it means
completions are being posted by target-core into fabric driver
code, but the responses aren't making it back to the host.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2017-01-19 15:45:57 -08:00 committed by Nicholas Bellinger
parent 17c61ad66f
commit c87ba9c49c
3 changed files with 22 additions and 0 deletions

View File

@ -158,12 +158,28 @@ static ssize_t target_stat_tgt_resets_show(struct config_item *item,
atomic_long_read(&to_stat_tgt_dev(item)->num_resets));
}
static ssize_t target_stat_tgt_aborts_complete_show(struct config_item *item,
char *page)
{
return snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&to_stat_tgt_dev(item)->aborts_complete));
}
static ssize_t target_stat_tgt_aborts_no_task_show(struct config_item *item,
char *page)
{
return snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&to_stat_tgt_dev(item)->aborts_no_task));
}
CONFIGFS_ATTR_RO(target_stat_tgt_, inst);
CONFIGFS_ATTR_RO(target_stat_tgt_, indx);
CONFIGFS_ATTR_RO(target_stat_tgt_, num_lus);
CONFIGFS_ATTR_RO(target_stat_tgt_, status);
CONFIGFS_ATTR_RO(target_stat_tgt_, non_access_lus);
CONFIGFS_ATTR_RO(target_stat_tgt_, resets);
CONFIGFS_ATTR_RO(target_stat_tgt_, aborts_complete);
CONFIGFS_ATTR_RO(target_stat_tgt_, aborts_no_task);
static struct configfs_attribute *target_stat_scsi_tgt_dev_attrs[] = {
&target_stat_tgt_attr_inst,
@ -172,6 +188,8 @@ static struct configfs_attribute *target_stat_scsi_tgt_dev_attrs[] = {
&target_stat_tgt_attr_status,
&target_stat_tgt_attr_non_access_lus,
&target_stat_tgt_attr_resets,
&target_stat_tgt_attr_aborts_complete,
&target_stat_tgt_attr_aborts_no_task,
NULL,
};

View File

@ -190,6 +190,7 @@ void core_tmr_abort_task(
printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
" ref_tag: %llu\n", ref_tag);
tmr->response = TMR_FUNCTION_COMPLETE;
atomic_long_inc(&dev->aborts_complete);
return;
}
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
@ -197,6 +198,7 @@ void core_tmr_abort_task(
printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
tmr->ref_task_tag);
tmr->response = TMR_TASK_DOES_NOT_EXIST;
atomic_long_inc(&dev->aborts_no_task);
}
static void core_tmr_drain_tmr_list(

View File

@ -766,6 +766,8 @@ struct se_device {
u32 dev_index;
u64 creation_time;
atomic_long_t num_resets;
atomic_long_t aborts_complete;
atomic_long_t aborts_no_task;
atomic_long_t num_cmds;
atomic_long_t read_bytes;
atomic_long_t write_bytes;