From c9e0332e877c1a1ccfe4ba315a437c7a8cf6e575 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 14 May 2013 13:52:32 -0700 Subject: [PATCH] blk-throttle: rename throtl_rb_root to throtl_service_queue throtl_rb_root will be expanded to cover more roles for hierarchy support. Rename it to throtl_service_queue and make its fields more descriptive. * rb -> pending_tree * left -> first_pending * count -> nr_pending * min_disptime -> first_pending_disptime This patch is purely cosmetic. Signed-off-by: Tejun Heo --- block/blk-throttle.c | 84 ++++++++++++++++++++++---------------------- 1 file changed, 42 insertions(+), 42 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index dbeef303f27b..b279110ba287 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -26,15 +26,15 @@ static struct blkcg_policy blkcg_policy_throtl; /* A workqueue to queue throttle related work */ static struct workqueue_struct *kthrotld_workqueue; -struct throtl_rb_root { - struct rb_root rb; - struct rb_node *left; - unsigned int count; - unsigned long min_disptime; +struct throtl_service_queue { + struct rb_root pending_tree; /* RB tree of active tgs */ + 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 */ }; -#define THROTL_RB_ROOT (struct throtl_rb_root) { .rb = RB_ROOT, .left = NULL, \ - .count = 0, .min_disptime = 0} +#define THROTL_SERVICE_QUEUE_INITIALIZER \ + (struct throtl_service_queue){ .pending_tree = RB_ROOT } #define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node) @@ -50,7 +50,7 @@ struct throtl_grp { /* must be the first member */ struct blkg_policy_data pd; - /* active throtl group service_tree member */ + /* active throtl group service_queue member */ struct rb_node rb_node; /* @@ -93,7 +93,7 @@ struct throtl_grp { struct throtl_data { /* service tree for active throtl groups */ - struct throtl_rb_root tg_service_tree; + struct throtl_service_queue service_queue; struct request_queue *queue; @@ -296,17 +296,17 @@ static struct throtl_grp *throtl_lookup_create_tg(struct throtl_data *td, return tg; } -static struct throtl_grp *throtl_rb_first(struct throtl_rb_root *root) +static struct throtl_grp *throtl_rb_first(struct throtl_service_queue *sq) { /* Service tree is empty */ - if (!root->count) + if (!sq->nr_pending) return NULL; - if (!root->left) - root->left = rb_first(&root->rb); + if (!sq->first_pending) + sq->first_pending = rb_first(&sq->pending_tree); - if (root->left) - return rb_entry_tg(root->left); + if (sq->first_pending) + return rb_entry_tg(sq->first_pending); return NULL; } @@ -317,29 +317,29 @@ static void rb_erase_init(struct rb_node *n, struct rb_root *root) RB_CLEAR_NODE(n); } -static void throtl_rb_erase(struct rb_node *n, struct throtl_rb_root *root) +static void throtl_rb_erase(struct rb_node *n, struct throtl_service_queue *sq) { - if (root->left == n) - root->left = NULL; - rb_erase_init(n, &root->rb); - --root->count; + if (sq->first_pending == n) + sq->first_pending = NULL; + rb_erase_init(n, &sq->pending_tree); + --sq->nr_pending; } -static void update_min_dispatch_time(struct throtl_rb_root *st) +static void update_min_dispatch_time(struct throtl_service_queue *sq) { struct throtl_grp *tg; - tg = throtl_rb_first(st); + tg = throtl_rb_first(sq); if (!tg) return; - st->min_disptime = tg->disptime; + sq->first_pending_disptime = tg->disptime; } -static void -tg_service_tree_add(struct throtl_rb_root *st, struct throtl_grp *tg) +static void tg_service_queue_add(struct throtl_service_queue *sq, + struct throtl_grp *tg) { - struct rb_node **node = &st->rb.rb_node; + struct rb_node **node = &sq->pending_tree.rb_node; struct rb_node *parent = NULL; struct throtl_grp *__tg; unsigned long key = tg->disptime; @@ -358,19 +358,19 @@ tg_service_tree_add(struct throtl_rb_root *st, struct throtl_grp *tg) } if (left) - st->left = &tg->rb_node; + sq->first_pending = &tg->rb_node; rb_link_node(&tg->rb_node, parent, node); - rb_insert_color(&tg->rb_node, &st->rb); + rb_insert_color(&tg->rb_node, &sq->pending_tree); } static void __throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg) { - struct throtl_rb_root *st = &td->tg_service_tree; + struct throtl_service_queue *sq = &td->service_queue; - tg_service_tree_add(st, tg); + tg_service_queue_add(sq, tg); throtl_mark_tg_on_rr(tg); - st->count++; + sq->nr_pending++; } static void throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg) @@ -381,7 +381,7 @@ static void throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg) static void __throtl_dequeue_tg(struct throtl_data *td, struct throtl_grp *tg) { - throtl_rb_erase(&tg->rb_node, &td->tg_service_tree); + throtl_rb_erase(&tg->rb_node, &td->service_queue); throtl_clear_tg_on_rr(tg); } @@ -403,18 +403,18 @@ static void throtl_schedule_delayed_work(struct throtl_data *td, static void throtl_schedule_next_dispatch(struct throtl_data *td) { - struct throtl_rb_root *st = &td->tg_service_tree; + struct throtl_service_queue *sq = &td->service_queue; /* any pending children left? */ - if (!st->count) + if (!sq->nr_pending) return; - update_min_dispatch_time(st); + update_min_dispatch_time(sq); - if (time_before_eq(st->min_disptime, jiffies)) + if (time_before_eq(sq->first_pending_disptime, jiffies)) throtl_schedule_delayed_work(td, 0); else - throtl_schedule_delayed_work(td, (st->min_disptime - jiffies)); + throtl_schedule_delayed_work(td, sq->first_pending_disptime - jiffies); } static inline void @@ -794,10 +794,10 @@ static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl) { unsigned int nr_disp = 0; struct throtl_grp *tg; - struct throtl_rb_root *st = &td->tg_service_tree; + struct throtl_service_queue *sq = &td->service_queue; while (1) { - tg = throtl_rb_first(st); + tg = throtl_rb_first(sq); if (!tg) break; @@ -1145,7 +1145,7 @@ void blk_throtl_drain(struct request_queue *q) __releases(q->queue_lock) __acquires(q->queue_lock) { struct throtl_data *td = q->td; - struct throtl_rb_root *st = &td->tg_service_tree; + struct throtl_service_queue *sq = &td->service_queue; struct throtl_grp *tg; struct bio_list bl; struct bio *bio; @@ -1154,7 +1154,7 @@ void blk_throtl_drain(struct request_queue *q) bio_list_init(&bl); - while ((tg = throtl_rb_first(st))) { + while ((tg = throtl_rb_first(sq))) { throtl_dequeue_tg(td, tg); while ((bio = bio_list_peek(&tg->bio_lists[READ]))) @@ -1179,7 +1179,7 @@ int blk_throtl_init(struct request_queue *q) if (!td) return -ENOMEM; - td->tg_service_tree = THROTL_RB_ROOT; + td->service_queue = THROTL_SERVICE_QUEUE_INITIALIZER; INIT_DELAYED_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); q->td = td; -- 2.30.2