blkio: Add root group to td->tg_list

o Currently all the dynamically allocated groups, except root grp is added
  to td->tg_list. This was not a problem so far but in next patch I will
  travel through td->tg_list to process any updates of limits on the group.
  If root group is not in tg_list, then root group's updates are not
  processed.

o It is better to root group also to tg_list instead of doing special
  processing for it during limit updates.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Vivek Goyal 2010-10-01 14:49:48 +02:00 committed by Jens Axboe
parent 61014e96e6
commit 02977e4af7

View File

@ -87,7 +87,7 @@ struct throtl_data
unsigned int nr_queued[2];
/*
* number of total undestroyed groups (excluding root group)
* number of total undestroyed groups
*/
unsigned int nr_undestroyed_grps;
@ -940,7 +940,17 @@ int blk_throtl_init(struct request_queue *q)
/* Practically unlimited BW */
tg->bps[0] = tg->bps[1] = -1;
tg->iops[0] = tg->iops[1] = -1;
atomic_set(&tg->ref, 1);
/*
* Set root group reference to 2. One reference will be dropped when
* all groups on tg_list are being deleted during queue exit. Other
* reference will remain there as we don't want to delete this group
* as it is statically allocated and gets destroyed when throtl_data
* goes away.
*/
atomic_set(&tg->ref, 2);
hlist_add_head(&tg->tg_node, &td->tg_list);
td->nr_undestroyed_grps++;
INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work);
@ -966,10 +976,9 @@ void blk_throtl_exit(struct request_queue *q)
spin_lock_irq(q->queue_lock);
throtl_release_tgs(td);
blkiocg_del_blkio_group(&td->root_tg.blkg);
/* If there are other groups */
if (td->nr_undestroyed_grps >= 1)
if (td->nr_undestroyed_grps > 0)
wait = true;
spin_unlock_irq(q->queue_lock);