blkio: Add io_queued and avg_queue_size stats
These stats are useful for getting a feel for the queue depth of the cgroup,
i.e., how filled up its queues are at a given instant and over the existence of
the cgroup. This ability is useful when debugging problems in the wild as it
helps understand the application's IO pattern w/o having to read through the
userspace code (coz its tedious or just not available) or w/o the ability
to run blktrace (since you may not have root access and/or not want to disturb
performance).
Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4eb1906..8e0b86a 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1380,7 +1380,12 @@
{
elv_rb_del(&cfqq->sort_list, rq);
cfqq->queued[rq_is_sync(rq)]--;
+ blkiocg_update_request_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
+ rq_is_sync(rq));
cfq_add_rq_rb(rq);
+ blkiocg_update_request_add_stats(
+ &cfqq->cfqg->blkg, &cfqq->cfqd->serving_group->blkg,
+ rq_data_dir(rq), rq_is_sync(rq));
}
static struct request *
@@ -1436,6 +1441,8 @@
cfq_del_rq_rb(rq);
cfqq->cfqd->rq_queued--;
+ blkiocg_update_request_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
+ rq_is_sync(rq));
if (rq_is_meta(rq)) {
WARN_ON(!cfqq->meta_pending);
cfqq->meta_pending--;
@@ -1527,6 +1534,7 @@
if (cfqq) {
cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
cfqd->serving_prio, cfqd->serving_type);
+ blkiocg_update_set_active_queue_stats(&cfqq->cfqg->blkg);
cfqq->slice_start = 0;
cfqq->dispatch_start = jiffies;
cfqq->allocated_slice = 0;
@@ -3213,6 +3221,9 @@
list_add_tail(&rq->queuelist, &cfqq->fifo);
cfq_add_rq_rb(rq);
+ blkiocg_update_request_add_stats(&cfqq->cfqg->blkg,
+ &cfqd->serving_group->blkg, rq_data_dir(rq),
+ rq_is_sync(rq));
cfq_rq_enqueued(cfqd, cfqq, rq);
}