diff options
| -rw-r--r-- | block/cfq-iosched.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 89e0d1cc14ba..12e380b2c4e4 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)) |