diff options
Diffstat (limited to 'block/blk-throttle.c')
| -rw-r--r-- | block/blk-throttle.c | 40 |
1 files changed, 33 insertions, 7 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 04202617fda5..bc65077f6e43 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -952,23 +952,33 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) * This timer is armed when a child throtl_grp with active bio's become * pending and queued on the service_queue's pending_tree and expires when * the first child throtl_grp should be dispatched. This function - * dispatches bio's from the children throtl_grps and kicks - * throtl_data->dispatch_work if there are bio's ready to be issued. + * dispatches bio's from the children throtl_grps to the parent + * service_queue. + * + * If the parent's parent is another throtl_grp, dispatching is propagated + * by either arming its pending_timer or repeating dispatch directly. If + * the top-level service_tree is reached, throtl_data->dispatch_work is + * kicked so that the ready bio's are issued. */ static void throtl_pending_timer_fn(unsigned long arg) { struct throtl_service_queue *sq = (void *)arg; + struct throtl_grp *tg = sq_to_tg(sq); struct throtl_data *td = sq_to_td(sq); struct request_queue *q = td->queue; - bool dispatched = false; + struct throtl_service_queue *parent_sq; + bool dispatched; int ret; spin_lock_irq(q->queue_lock); +again: + parent_sq = sq->parent_sq; + dispatched = false; while (true) { throtl_log(sq, "dispatch nr_queued=%u read=%u write=%u", - td->nr_queued[READ] + td->nr_queued[WRITE], - td->nr_queued[READ], td->nr_queued[WRITE]); + sq->nr_queued[READ] + sq->nr_queued[WRITE], + sq->nr_queued[READ], sq->nr_queued[WRITE]); ret = throtl_select_dispatch(sq); if (ret) { @@ -985,9 +995,25 @@ static void throtl_pending_timer_fn(unsigned long arg) spin_lock_irq(q->queue_lock); } - if (dispatched) - queue_work(kthrotld_workqueue, &td->dispatch_work); + if (!dispatched) + goto out_unlock; + if (parent_sq) { + /* @parent_sq is another throl_grp, propagate dispatch */ + if (tg->flags & THROTL_TG_WAS_EMPTY) { + tg_update_disptime(tg); + if (!throtl_schedule_next_dispatch(parent_sq, false)) { + /* window is already open, repeat dispatching */ + sq = parent_sq; + tg = sq_to_tg(sq); + goto again; + } + } + } else { + /* reached the top-level, queue issueing */ + queue_work(kthrotld_workqueue, &td->dispatch_work); + } +out_unlock: spin_unlock_irq(q->queue_lock); } |