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-rw-r--r--block/cfq-iosched.c53
1 files changed, 41 insertions, 12 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 89e0d1c..12e380b 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -178,6 +178,8 @@ struct cfq_group {
/* group service_tree key */
u64 vdisktime;
unsigned int weight;
+ unsigned int new_weight;
+ bool needs_update;
/* number of cfqq currently on this group */
int nr_cfqq;
@@ -853,7 +855,27 @@ __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
}
static void
-cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
+cfq_update_group_weight(struct cfq_group *cfqg)
+{
+ BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
+ if (cfqg->needs_update) {
+ cfqg->weight = cfqg->new_weight;
+ cfqg->needs_update = false;
+ }
+}
+
+static void
+cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
+{
+ BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
+
+ cfq_update_group_weight(cfqg);
+ __cfq_group_service_tree_add(st, cfqg);
+ st->total_weight += cfqg->weight;
+}
+
+static void
+cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
struct cfq_rb_root *st = &cfqd->grp_service_tree;
struct cfq_group *__cfqg;
@@ -874,13 +896,19 @@ cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY;
} else
cfqg->vdisktime = st->min_vdisktime;
+ cfq_group_service_tree_add(st, cfqg);
+}
- __cfq_group_service_tree_add(st, cfqg);
- st->total_weight += cfqg->weight;
+static void
+cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg)
+{
+ st->total_weight -= cfqg->weight;
+ if (!RB_EMPTY_NODE(&cfqg->rb_node))
+ cfq_rb_erase(&cfqg->rb_node, st);
}
static void
-cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
+cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
struct cfq_rb_root *st = &cfqd->grp_service_tree;
@@ -892,9 +920,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
return;
cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
- st->total_weight -= cfqg->weight;
- if (!RB_EMPTY_NODE(&cfqg->rb_node))
- cfq_rb_erase(&cfqg->rb_node, st);
+ cfq_group_service_tree_del(st, cfqg);
cfqg->saved_workload_slice = 0;
cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
}
@@ -948,9 +974,10 @@ 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(&cfqg->rb_node, st);
+ cfq_group_service_tree_del(st, cfqg);
cfqg->vdisktime += cfq_scale_slice(charge, cfqg);
- __cfq_group_service_tree_add(st, cfqg);
+ /* If a new weight was requested, update now, off tree */
+ cfq_group_service_tree_add(st, cfqg);
/* This group is being expired. Save the context */
if (time_after(cfqd->workload_expires, jiffies)) {
@@ -982,7 +1009,9 @@ static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg)
void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg,
unsigned int weight)
{
- cfqg_of_blkg(blkg)->weight = weight;
+ struct cfq_group *cfqg = cfqg_of_blkg(blkg);
+ cfqg->new_weight = weight;
+ cfqg->needs_update = true;
}
static struct cfq_group *
@@ -1255,7 +1284,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
service_tree->count++;
if ((add_front || !new_cfqq) && !group_changed)
return;
- cfq_group_service_tree_add(cfqd, cfqq->cfqg);
+ cfq_group_notify_queue_add(cfqd, cfqq->cfqg);
}
static struct cfq_queue *
@@ -1368,7 +1397,7 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
cfqq->p_root = NULL;
}
- cfq_group_service_tree_del(cfqd, cfqq->cfqg);
+ cfq_group_notify_queue_del(cfqd, cfqq->cfqg);
BUG_ON(!cfqd->busy_queues);
cfqd->busy_queues--;
if (cfq_cfqq_sync(cfqq))