Commit c9e0332e authored by Tejun Heo's avatar Tejun Heo
Browse files

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: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
parent 6a525600

block/blk-throttle.c

+42 −42
Original line number Diff line number Diff line
@@ -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;

CRA Git | Maintained and supported by SUSTech CRA and CCSE