[PATCH 07/20] blkio: Provide capablity to enqueue/dequeue group entities
From: Vivek Goyal
Date: Tue Nov 03 2009 - 18:47:00 EST
o This patch embeds cfq_entity object in cfq_group and provides helper routines
so that group entities can be scheduled.
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
block/cfq-iosched.c | 110 +++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 93 insertions(+), 17 deletions(-)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index bc99163..8ec8a82 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -79,6 +79,7 @@ struct cfq_service_tree {
#define CFQ_RB_ROOT (struct cfq_service_tree) { RB_ROOT, NULL, 0, NULL}
struct cfq_sched_data {
+ unsigned int nr_active;
struct cfq_service_tree service_tree[IO_IOPRIO_CLASSES];
};
@@ -89,6 +90,10 @@ struct cfq_entity {
struct cfq_service_tree *st;
unsigned short ioprio_class;
bool ioprio_class_changed;
+ struct cfq_entity *parent;
+ bool on_st;
+ /* Points to the sched_data of group entity. Null for cfqq */
+ struct cfq_sched_data *my_sd;
};
/*
@@ -136,6 +141,7 @@ struct cfq_queue {
/* Per cgroup grouping structure */
struct cfq_group {
+ struct cfq_entity entity;
struct cfq_sched_data sched_data;
#ifdef CONFIG_CFQ_GROUP_IOSCHED
struct blkio_group blkg;
@@ -260,9 +266,23 @@ static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *,
static void cfq_put_queue(struct cfq_queue *cfqq);
static struct cfq_entity *__cfq_get_next_entity(struct cfq_service_tree *st);
+static inline struct cfq_entity *parent_entity(struct cfq_entity *cfqe)
+{
+ return cfqe->parent;
+}
+
static inline struct cfq_queue *cfqq_of(struct cfq_entity *cfqe)
{
- return container_of(cfqe, struct cfq_queue, entity);
+ if (!cfqe->my_sd)
+ return container_of(cfqe, struct cfq_queue, entity);
+ return NULL;
+}
+
+static inline struct cfq_group *cfqg_of(struct cfq_entity *cfqe)
+{
+ if (cfqe->my_sd)
+ return container_of(cfqe, struct cfq_group, entity);
+ return NULL;
}
static inline void
@@ -352,6 +372,33 @@ cfq_weight_slice(struct cfq_data *cfqd, int sync, unsigned int weight)
return cfq_delta(base_slice, weight, BLKIO_WEIGHT_DEFAULT);
}
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+/* check for entity->parent so that loop is not executed for root entity. */
+#define for_each_entity(entity) \
+ for (; entity && entity->parent; entity = entity->parent)
+
+static inline struct cfq_sched_data *
+cfq_entity_sched_data(struct cfq_entity *cfqe)
+{
+ return &cfqg_of(parent_entity(cfqe))->sched_data;
+}
+#else /* CONFIG_CFQ_GROUP_IOSCHED */
+#define for_each_entity(entity) \
+ for (; entity != NULL; entity = NULL)
+static inline struct cfq_data *cfqd_of(struct cfq_entity *cfqe)
+{
+ return cfqq_of(cfqe)->cfqd;
+}
+
+static inline struct cfq_sched_data *
+cfq_entity_sched_data(struct cfq_entity *cfqe)
+{
+ struct cfq_data *cfqd = cfqd_of(cfqe);
+
+ return &cfqd->root_group.sched_data;
+}
+#endif /* CONFIG_CFQ_GROUP_IOSCHED */
+
static inline int rq_in_driver(struct cfq_data *cfqd)
{
return cfqd->rq_in_driver[0] + cfqd->rq_in_driver[1];
@@ -606,16 +653,28 @@ static void __dequeue_cfqe(struct cfq_service_tree *st, struct cfq_entity *cfqe)
static void dequeue_cfqe(struct cfq_entity *cfqe)
{
struct cfq_service_tree *st = cfqe->st;
+ struct cfq_sched_data *sd = cfq_entity_sched_data(cfqe);
if (st->active == cfqe)
st->active = NULL;
__dequeue_cfqe(st, cfqe);
+ sd->nr_active--;
+ cfqe->on_st = 0;
}
static void dequeue_cfqq(struct cfq_queue *cfqq)
{
- dequeue_cfqe(&cfqq->entity);
+ struct cfq_entity *cfqe = &cfqq->entity;
+
+ for_each_entity(cfqe) {
+ struct cfq_sched_data *sd = cfq_entity_sched_data(cfqe);
+
+ dequeue_cfqe(cfqe);
+ /* Do not dequeue parent if it has other entities under it */
+ if (sd->nr_active)
+ break;
+ }
}
static void __enqueue_cfqe(struct cfq_service_tree *st, struct cfq_entity *cfqe,
@@ -653,6 +712,10 @@ static void __enqueue_cfqe(struct cfq_service_tree *st, struct cfq_entity *cfqe,
static void enqueue_cfqe(struct cfq_entity *cfqe)
{
+ struct cfq_sched_data *sd = cfq_entity_sched_data(cfqe);
+
+ cfqe->on_st = 1;
+ sd->nr_active++;
cfqe_update_ioprio_class(cfqe);
place_cfqe(cfqe->st, cfqe, 0);
__enqueue_cfqe(cfqe->st, cfqe, 0);
@@ -660,7 +723,13 @@ static void enqueue_cfqe(struct cfq_entity *cfqe)
static void enqueue_cfqq(struct cfq_queue *cfqq)
{
- enqueue_cfqe(&cfqq->entity);
+ struct cfq_entity *cfqe = &cfqq->entity;
+
+ for_each_entity(cfqe) {
+ if (cfqe->on_st)
+ break;
+ enqueue_cfqe(cfqe);
+ }
}
/* Requeue a cfqq which is already on the service tree */
@@ -687,14 +756,22 @@ static void requeue_cfqq(struct cfq_queue *cfqq, int add_front)
static void cfqe_served(struct cfq_entity *cfqe, unsigned long served)
{
- /*
- * Can't update entity disk time while it is on sorted rb-tree
- * as vdisktime is used as key.
- */
- __dequeue_cfqe(cfqe->st, cfqe);
- cfqe->vdisktime += cfq_delta_fair(served, cfqe);
- update_min_vdisktime(cfqe->st);
- __enqueue_cfqe(cfqe->st, cfqe, 0);
+ for_each_entity(cfqe) {
+ /*
+ * Can't update entity disk time while it is on sorted rb-tree
+ * as vdisktime is used as key.
+ */
+ __dequeue_cfqe(cfqe->st, cfqe);
+ cfqe->vdisktime += cfq_delta_fair(served, cfqe);
+ update_min_vdisktime(cfqe->st);
+ __enqueue_cfqe(cfqe->st, cfqe, 0);
+
+ /* If entity prio class has changed, take that into account */
+ if (unlikely(cfqe->ioprio_class_changed)) {
+ dequeue_cfqe(cfqe);
+ enqueue_cfqe(cfqe);
+ }
+ }
}
static void cfqq_served(struct cfq_queue *cfqq, unsigned long served)
@@ -708,12 +785,6 @@ static void cfqq_served(struct cfq_queue *cfqq, unsigned long served)
*/
served = cfq_prio_to_slice(cfqq->cfqd, cfqq);
cfqe_served(&cfqq->entity, served);
-
- /* If cfqq prio class has changed, take that into account */
- if (unlikely(cfqq->entity.ioprio_class_changed)) {
- dequeue_cfqq(cfqq);
- enqueue_cfqq(cfqq);
- }
}
/*
@@ -1941,6 +2012,8 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfq_mark_cfqq_sync(cfqq);
}
cfqq->pid = pid;
+ cfqq->entity.parent = &cfqd->root_group.entity;
+ cfqq->entity.my_sd = NULL;
}
static struct cfq_queue *
@@ -2707,6 +2780,9 @@ static void cfq_init_root_group(struct cfq_data *cfqd)
struct cfq_group *cfqg = &cfqd->root_group;
int i;
+ cfqg->entity.parent = NULL;
+ cfqg->entity.my_sd = &cfqg->sched_data;
+
for (i = 0; i < IO_IOPRIO_CLASSES; i++)
cfqg->sched_data.service_tree[i] = CFQ_RB_ROOT;
}
--
1.6.2.5
--
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