2010-11-15 00:56:48

by Gui, Jianfeng/归 剑峰

[permalink] [raw]
Subject: [RFC] [PATCH 5/8] cfq-iosched: Extract some common code of service tree handling for CFQ queue and CFQ group.

Extract some common code of service tree handling for CFQ queue
and CFQ group. This helps when CFQ queue and CFQ group are scheduling
together.

Signed-off-by: Gui Jianfeng <[email protected]>
---
block/cfq-iosched.c | 114 ++++++++++++++++++++++----------------------------
1 files changed, 50 insertions(+), 64 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ad577b5..1b9b4b2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -855,20 +855,20 @@ entity_key(struct cfq_rb_root *st, struct io_sched_entity *entity)
}

static void
-__cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
+__io_entity_service_tree_add(struct cfq_rb_root *st,
+ struct io_sched_entity *io_entity)
{
struct rb_node **node = &st->rb.rb_node;
struct rb_node *parent = NULL;
- struct io_sched_entity *__group_entity;
- struct io_sched_entity *group_entity = &cfqg->group_entity;
- s64 key = entity_key(st, group_entity);
+ struct io_sched_entity *__io_entity;
+ s64 key = entity_key(st, io_entity);
int left = 1;

while (*node != NULL) {
parent = *node;
- __group_entity = rb_entry_entity(parent);
+ __io_entity = rb_entry_entity(parent);

- if (key < entity_key(st, __group_entity))
+ if (key < entity_key(st, __io_entity))
node = &parent->rb_left;
else {
node = &parent->rb_right;
@@ -877,10 +877,21 @@ __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
}

if (left)
- st->left = &group_entity->rb_node;
+ st->left = &io_entity->rb_node;

- rb_link_node(&group_entity->rb_node, parent, node);
- rb_insert_color(&group_entity->rb_node, &st->rb);
+ rb_link_node(&io_entity->rb_node, parent, node);
+ rb_insert_color(&io_entity->rb_node, &st->rb);
+}
+
+static void
+io_entity_service_tree_add(struct cfq_rb_root *st,
+ struct io_sched_entity *io_entity)
+{
+ __io_entity_service_tree_add(st, io_entity);
+ st->count++;
+ st->total_weight += io_entity->weight;
+ if (io_entity->is_group_entity)
+ io_entity->on_st = true;
}

static void
@@ -908,9 +919,27 @@ cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
} else
group_entity->vdisktime = st->min_vdisktime;

- __cfq_group_service_tree_add(st, cfqg);
- group_entity->on_st = true;
- st->total_weight += group_entity->weight;
+ io_entity_service_tree_add(st, group_entity);
+}
+
+static void
+__io_entity_service_tree_del(struct cfq_rb_root *st,
+ struct io_sched_entity *io_entity)
+{
+ cfq_rb_erase(&io_entity->rb_node, st);
+}
+
+static void
+io_entity_service_tree_del(struct cfq_rb_root *st,
+ struct io_sched_entity *io_entity)
+{
+ if (!RB_EMPTY_NODE(&io_entity->rb_node)) {
+ __io_entity_service_tree_del(st, io_entity);
+ st->total_weight -= io_entity->weight;
+ if (io_entity->is_group_entity)
+ io_entity->on_st = false;
+ io_entity->service_tree = NULL;
+ }
}

static void
@@ -927,10 +956,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
return;

cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
- group_entity->on_st = false;
- st->total_weight -= group_entity->weight;
- if (!RB_EMPTY_NODE(&group_entity->rb_node))
- cfq_rb_erase(&group_entity->rb_node, st);
+ io_entity_service_tree_del(st, group_entity);
cfqg->saved_workload_slice = 0;
cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
}
@@ -979,9 +1005,9 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
charge = cfqq->allocated_slice;

/* Can't update vdisktime while group is on service tree */
- cfq_rb_erase(&group_entity->rb_node, st);
+ __io_entity_service_tree_del(st, group_entity);
group_entity->vdisktime += cfq_scale_slice(charge, group_entity);
- __cfq_group_service_tree_add(st, cfqg);
+ __io_entity_service_tree_add(st, group_entity);

/* This group is being expired. Save the context */
if (time_after(cfqd->workload_expires, jiffies)) {
@@ -1209,13 +1235,11 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
bool add_front)
{
struct io_sched_entity *queue_entity;
- struct rb_node **p, *parent;
+ struct rb_node *parent;
struct io_sched_entity *__queue_entity;
struct cfq_rb_root *service_tree, *orig_st;
- int left;
int new_cfqq = 1;
int group_changed = 0;
- s64 key;

queue_entity = &cfqq->queue_entity;
orig_st = queue_entity->service_tree;
@@ -1232,9 +1256,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
* Group changed, dequeue this CFQ queue from the
* original service tree.
*/
- cfq_rb_erase(&queue_entity->rb_node,
- queue_entity->service_tree);
- orig_st->total_weight -= queue_entity->weight;
+ io_entity_service_tree_del(orig_st, queue_entity);
}
cfqq->orig_cfqg = cfqq->cfqg;
cfqq->cfqg = &cfqd->root_group;
@@ -1250,9 +1272,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
* Group changed, dequeue this CFQ queue from the
* original service tree.
*/
- cfq_rb_erase(&queue_entity->rb_node,
- queue_entity->service_tree);
- orig_st->total_weight -= queue_entity->weight;
+ io_entity_service_tree_del(orig_st, queue_entity);
}
cfq_put_cfqg(cfqq->cfqg);
cfqq->cfqg = cfqq->orig_cfqg;
@@ -1290,9 +1310,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
* Ok, we get here, this CFQ queue is on the service tree, dequeue it
* firstly.
*/
- cfq_rb_erase(&queue_entity->rb_node,
- queue_entity->service_tree);
- orig_st->total_weight -= queue_entity->weight;
+ io_entity_service_tree_del(orig_st, queue_entity);

new_cfqq = 0;
if (cfq_class_idle(cfqq)) {
@@ -1320,39 +1338,10 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
}

insert:
- left = 1;
- parent = NULL;
queue_entity->service_tree = service_tree;
- p = &service_tree->rb.rb_node;
- key = entity_key(service_tree, queue_entity);
- while (*p) {
- struct rb_node **n;
-
- parent = *p;
- __queue_entity = rb_entry(parent, struct io_sched_entity,
- rb_node);
-
- /*
- * sort by key, that represents service time.
- */
- if (key < entity_key(service_tree, __queue_entity))
- n = &(*p)->rb_left;
- else {
- n = &(*p)->rb_right;
- left = 0;
- }
-
- p = n;
- }
-
- if (left)
- service_tree->left = &queue_entity->rb_node;
+ io_entity_service_tree_add(service_tree, queue_entity);

- rb_link_node(&queue_entity->rb_node, parent, p);
- rb_insert_color(&queue_entity->rb_node, &service_tree->rb);
update_min_vdisktime(service_tree);
- service_tree->count++;
- service_tree->total_weight += queue_entity->weight;
cfqq->reposition_time = jiffies;
if ((add_front || !new_cfqq) && !group_changed)
return;
@@ -1465,10 +1454,7 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
service_tree = queue_entity->service_tree;

if (!RB_EMPTY_NODE(&queue_entity->rb_node)) {
- cfq_rb_erase(&queue_entity->rb_node,
- queue_entity->service_tree);
- service_tree->total_weight -= queue_entity->weight;
- queue_entity->service_tree = NULL;
+ io_entity_service_tree_del(service_tree, queue_entity);
}
if (cfqq->p_root) {
rb_erase(&cfqq->p_node, cfqq->p_root);
--
1.6.5.2