diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-throttle.c | 74 |
1 files changed, 20 insertions, 54 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 3960787358b6..7dbd0e695df0 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -85,9 +85,6 @@ struct throtl_grp { unsigned long slice_start[2]; unsigned long slice_end[2]; - /* Some throttle limits got updated for the group */ - int limits_changed; - /* Per cpu stats pointer */ struct tg_stats_cpu __percpu *stats_cpu; @@ -112,8 +109,6 @@ struct throtl_data /* Work for dispatching throttled bios */ struct delayed_work throtl_work; - - int limits_changed; }; /* list and work item to allocate percpu group stats */ @@ -223,7 +218,6 @@ static void throtl_pd_init(struct blkcg_gq *blkg) RB_CLEAR_NODE(&tg->rb_node); bio_list_init(&tg->bio_lists[0]); bio_list_init(&tg->bio_lists[1]); - tg->limits_changed = false; tg->bps[READ] = -1; tg->bps[WRITE] = -1; @@ -826,45 +820,6 @@ static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl) return nr_disp; } -static void throtl_process_limit_change(struct throtl_data *td) -{ - struct request_queue *q = td->queue; - struct blkcg_gq *blkg, *n; - - if (!td->limits_changed) - return; - - xchg(&td->limits_changed, false); - - throtl_log(td, "limits changed"); - - list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) { - struct throtl_grp *tg = blkg_to_tg(blkg); - - if (!tg->limits_changed) - continue; - - if (!xchg(&tg->limits_changed, false)) - continue; - - throtl_log_tg(td, tg, "limit change rbps=%llu wbps=%llu" - " riops=%u wiops=%u", tg->bps[READ], tg->bps[WRITE], - tg->iops[READ], tg->iops[WRITE]); - - /* - * Restart the slices for both READ and WRITES. It - * might happen that a group's limit are dropped - * suddenly and we don't want to account recently - * dispatched IO with new low rate - */ - throtl_start_new_slice(td, tg, 0); - throtl_start_new_slice(td, tg, 1); - - if (throtl_tg_on_rr(tg)) - tg_update_disptime(td, tg); - } -} - /* Dispatch throttled bios. Should be called without queue lock held. */ static int throtl_dispatch(struct request_queue *q) { @@ -876,8 +831,6 @@ static int throtl_dispatch(struct request_queue *q) spin_lock_irq(q->queue_lock); - throtl_process_limit_change(td); - if (!total_nr_queued(td)) goto out; @@ -925,8 +878,7 @@ throtl_schedule_delayed_work(struct throtl_data *td, unsigned long delay) struct delayed_work *dwork = &td->throtl_work; - /* schedule work if limits changed even if no bio is queued */ - if (total_nr_queued(td) || td->limits_changed) { + if (total_nr_queued(td)) { mod_delayed_work(kthrotld_workqueue, dwork, delay); throtl_log(td, "schedule work. delay=%lu jiffies=%lu", delay, jiffies); @@ -1023,10 +975,25 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, else *(unsigned int *)((void *)tg + cft->private) = ctx.v; - /* XXX: we don't need the following deferred processing */ - xchg(&tg->limits_changed, true); - xchg(&td->limits_changed, true); - throtl_schedule_delayed_work(td, 0); + throtl_log_tg(td, tg, "limit change rbps=%llu wbps=%llu riops=%u wiops=%u", + tg->bps[READ], tg->bps[WRITE], + tg->iops[READ], tg->iops[WRITE]); + + /* + * We're already holding queue_lock and know @tg is valid. Let's + * apply the new config directly. + * + * Restart the slices for both READ and WRITES. It might happen + * that a group's limit are dropped suddenly and we don't want to + * account recently dispatched IO with new low rate. + */ + throtl_start_new_slice(td, tg, 0); + throtl_start_new_slice(td, tg, 1); + + if (throtl_tg_on_rr(tg)) { + tg_update_disptime(td, tg); + throtl_schedule_next_dispatch(td); + } blkg_conf_finish(&ctx); return 0; @@ -1239,7 +1206,6 @@ int blk_throtl_init(struct request_queue *q) return -ENOMEM; td->tg_service_tree = THROTL_RB_ROOT; - td->limits_changed = false; INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work); q->td = td; |