diff options
Diffstat (limited to 'block/blk-throttle.c')
| -rw-r--r-- | block/blk-throttle.c | 68 |
1 files changed, 45 insertions, 23 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 420eaa150d11..a8d23f0cf357 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -44,6 +44,7 @@ struct throtl_service_queue { struct rb_node *first_pending; /* first node in the tree */ unsigned int nr_pending; /* # queued in the tree */ unsigned long first_pending_disptime; /* disptime of the first tg */ + struct timer_list pending_timer; /* fires on first_pending_disptime */ }; enum tg_state_flags { @@ -121,7 +122,7 @@ struct throtl_data unsigned int nr_undestroyed_grps; /* Work for dispatching throttled bios */ - struct delayed_work dispatch_work; + struct work_struct dispatch_work; }; /* list and work item to allocate percpu group stats */ @@ -131,6 +132,8 @@ static LIST_HEAD(tg_stats_alloc_list); static void tg_stats_alloc_fn(struct work_struct *); static DECLARE_DELAYED_WORK(tg_stats_alloc_work, tg_stats_alloc_fn); +static void throtl_pending_timer_fn(unsigned long arg); + static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd) { return pd ? container_of(pd, struct throtl_grp, pd) : NULL; @@ -255,6 +258,13 @@ static void throtl_service_queue_init(struct throtl_service_queue *sq, bio_list_init(&sq->bio_lists[1]); sq->pending_tree = RB_ROOT; sq->parent_sq = parent_sq; + setup_timer(&sq->pending_timer, throtl_pending_timer_fn, + (unsigned long)sq); +} + +static void throtl_service_queue_exit(struct throtl_service_queue *sq) +{ + del_timer_sync(&sq->pending_timer); } static void throtl_pd_init(struct blkcg_gq *blkg) @@ -293,6 +303,8 @@ static void throtl_pd_exit(struct blkcg_gq *blkg) spin_unlock_irqrestore(&tg_stats_alloc_lock, flags); free_percpu(tg->stats_cpu); + + throtl_service_queue_exit(&tg->service_queue); } static void throtl_pd_reset_stats(struct blkcg_gq *blkg) @@ -447,19 +459,17 @@ static void throtl_dequeue_tg(struct throtl_grp *tg) } /* Call with queue lock held */ -static void throtl_schedule_delayed_work(struct throtl_data *td, - unsigned long delay) +static void throtl_schedule_pending_timer(struct throtl_service_queue *sq, + unsigned long expires) { - struct delayed_work *dwork = &td->dispatch_work; - struct throtl_service_queue *sq = &td->service_queue; - - mod_delayed_work(kthrotld_workqueue, dwork, delay); - throtl_log(sq, "schedule work. delay=%lu jiffies=%lu", delay, jiffies); + mod_timer(&sq->pending_timer, expires); + throtl_log(sq, "schedule timer. delay=%lu jiffies=%lu", + expires - jiffies, jiffies); } -static void throtl_schedule_next_dispatch(struct throtl_data *td) +static void throtl_schedule_next_dispatch(struct throtl_service_queue *sq) { - struct throtl_service_queue *sq = &td->service_queue; + struct throtl_data *td = sq_to_td(sq); /* any pending children left? */ if (!sq->nr_pending) @@ -467,10 +477,14 @@ static void throtl_schedule_next_dispatch(struct throtl_data *td) update_min_dispatch_time(sq); - if (time_before_eq(sq->first_pending_disptime, jiffies)) - throtl_schedule_delayed_work(td, 0); - else - throtl_schedule_delayed_work(td, sq->first_pending_disptime - jiffies); + /* is the next dispatch time in the future? */ + if (time_after(sq->first_pending_disptime, jiffies)) { + throtl_schedule_pending_timer(sq, sq->first_pending_disptime); + return; + } + + /* kick immediate execution */ + queue_work(kthrotld_workqueue, &td->dispatch_work); } static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw) @@ -901,11 +915,19 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) return nr_disp; } +static void throtl_pending_timer_fn(unsigned long arg) +{ + struct throtl_service_queue *sq = (void *)arg; + struct throtl_data *td = sq_to_td(sq); + + queue_work(kthrotld_workqueue, &td->dispatch_work); +} + /* work function to dispatch throttled bios */ void blk_throtl_dispatch_work_fn(struct work_struct *work) { - struct throtl_data *td = container_of(to_delayed_work(work), - struct throtl_data, dispatch_work); + struct throtl_data *td = container_of(work, struct throtl_data, + dispatch_work); struct throtl_service_queue *sq = &td->service_queue; struct request_queue *q = td->queue; unsigned int nr_disp = 0; @@ -932,7 +954,7 @@ void blk_throtl_dispatch_work_fn(struct work_struct *work) throtl_log(sq, "bios disp=%u", nr_disp); } - throtl_schedule_next_dispatch(td); + throtl_schedule_next_dispatch(sq); spin_unlock_irq(q->queue_lock); @@ -1020,7 +1042,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, struct blkcg *blkcg = cgroup_to_blkcg(cgrp); struct blkg_conf_ctx ctx; struct throtl_grp *tg; - struct throtl_data *td; + struct throtl_service_queue *sq; int ret; ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); @@ -1028,7 +1050,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, return ret; tg = blkg_to_tg(ctx.blkg); - td = ctx.blkg->q->td; + sq = &tg->service_queue; if (!ctx.v) ctx.v = -1; @@ -1056,7 +1078,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, if (tg->flags & THROTL_TG_PENDING) { tg_update_disptime(tg); - throtl_schedule_next_dispatch(td); + throtl_schedule_next_dispatch(sq->parent_sq); } blkg_conf_finish(&ctx); @@ -1121,7 +1143,7 @@ static void throtl_shutdown_wq(struct request_queue *q) { struct throtl_data *td = q->td; - cancel_delayed_work_sync(&td->dispatch_work); + cancel_work_sync(&td->dispatch_work); } static struct blkcg_policy blkcg_policy_throtl = { @@ -1210,7 +1232,7 @@ queue_bio: /* update @tg's dispatch time if @tg was empty before @bio */ if (tg->flags & THROTL_TG_WAS_EMPTY) { tg_update_disptime(tg); - throtl_schedule_next_dispatch(td); + throtl_schedule_next_dispatch(tg->service_queue.parent_sq); } out_unlock: @@ -1273,7 +1295,7 @@ int blk_throtl_init(struct request_queue *q) if (!td) return -ENOMEM; - INIT_DELAYED_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); + INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); throtl_service_queue_init(&td->service_queue, NULL); q->td = td; |