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authorTejun Heo <tj@kernel.org>2013-05-14 13:52:32 -0700
committerTejun Heo <tj@kernel.org>2013-05-14 13:52:32 -0700
commitc9e0332e877c1a1ccfe4ba315a437c7a8cf6e575 (patch)
treed5bab892cad9080643d619684e9d3dc59f320022
parent6a525600ffeb9e0d6cbbebda49eb89d6d3408c2b (diff)
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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 <tj@kernel.org Acked-by: Vivek Goyal <vgoyal@redhat.com>
-rw-r--r--block/blk-throttle.c84
1 files 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;