diff options
| -rw-r--r-- | block/cfq-iosched.c | 57 |
1 files changed, 56 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index f8b34bbbd372..4d75b7944574 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -289,7 +289,8 @@ struct cfq_group { /* number of requests that are on the dispatch list or inside driver */ int dispatched; struct cfq_ttime ttime; - struct cfqg_stats stats; + struct cfqg_stats stats; /* stats for this cfqg */ + struct cfqg_stats dead_stats; /* stats pushed from dead children */ }; struct cfq_io_cq { @@ -709,6 +710,47 @@ static void cfqg_stats_reset(struct cfqg_stats *stats) #endif } +/* @to += @from */ +static void cfqg_stats_merge(struct cfqg_stats *to, struct cfqg_stats *from) +{ + /* queued stats shouldn't be cleared */ + blkg_rwstat_merge(&to->service_bytes, &from->service_bytes); + blkg_rwstat_merge(&to->serviced, &from->serviced); + blkg_rwstat_merge(&to->merged, &from->merged); + blkg_rwstat_merge(&to->service_time, &from->service_time); + blkg_rwstat_merge(&to->wait_time, &from->wait_time); + blkg_stat_merge(&from->time, &from->time); +#ifdef CONFIG_DEBUG_BLK_CGROUP + blkg_stat_merge(&to->unaccounted_time, &from->unaccounted_time); + blkg_stat_merge(&to->avg_queue_size_sum, &from->avg_queue_size_sum); + blkg_stat_merge(&to->avg_queue_size_samples, &from->avg_queue_size_samples); + blkg_stat_merge(&to->dequeue, &from->dequeue); + blkg_stat_merge(&to->group_wait_time, &from->group_wait_time); + blkg_stat_merge(&to->idle_time, &from->idle_time); + blkg_stat_merge(&to->empty_time, &from->empty_time); +#endif +} + +/* + * Transfer @cfqg's stats to its parent's dead_stats so that the ancestors' + * recursive stats can still account for the amount used by this cfqg after + * it's gone. + */ +static void cfqg_stats_xfer_dead(struct cfq_group *cfqg) +{ + struct cfq_group *parent = cfqg_parent(cfqg); + + lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock); + + if (unlikely(!parent)) + return; + + cfqg_stats_merge(&parent->dead_stats, &cfqg->stats); + cfqg_stats_merge(&parent->dead_stats, &cfqg->dead_stats); + cfqg_stats_reset(&cfqg->stats); + cfqg_stats_reset(&cfqg->dead_stats); +} + #else /* CONFIG_CFQ_GROUP_IOSCHED */ static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; } @@ -1475,11 +1517,23 @@ static void cfq_pd_init(struct blkcg_gq *blkg) cfqg->leaf_weight = blkg->blkcg->cfq_leaf_weight; } +static void cfq_pd_offline(struct blkcg_gq *blkg) +{ + /* + * @blkg is going offline and will be ignored by + * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so + * that they don't get lost. If IOs complete after this point, the + * stats for them will be lost. Oh well... + */ + cfqg_stats_xfer_dead(blkg_to_cfqg(blkg)); +} + static void cfq_pd_reset_stats(struct blkcg_gq *blkg) { struct cfq_group *cfqg = blkg_to_cfqg(blkg); cfqg_stats_reset(&cfqg->stats); + cfqg_stats_reset(&cfqg->dead_stats); } /* @@ -4408,6 +4462,7 @@ static struct blkcg_policy blkcg_policy_cfq = { .cftypes = cfq_blkcg_files, .pd_init_fn = cfq_pd_init, + .pd_offline_fn = cfq_pd_offline, .pd_reset_stats_fn = cfq_pd_reset_stats, }; #endif |