diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index e00d0458a9d6..696d28151c9a 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -711,6 +711,77 @@ void blkg_conf_finish(struct blkg_conf_ctx *ctx) } EXPORT_SYMBOL_GPL(blkg_conf_finish); +static void blkg_iostat_set(struct blkg_iostat *dst, struct blkg_iostat *src) +{ + int i; + + for (i = 0; i < BLKG_IOSTAT_NR; i++) { + dst->bytes[i] = src->bytes[i]; + dst->ios[i] = src->ios[i]; + } +} + +static void blkg_iostat_add(struct blkg_iostat *dst, struct blkg_iostat *src) +{ + int i; + + for (i = 0; i < BLKG_IOSTAT_NR; i++) { + dst->bytes[i] += src->bytes[i]; + dst->ios[i] += src->ios[i]; + } +} + +static void blkg_iostat_sub(struct blkg_iostat *dst, struct blkg_iostat *src) +{ + int i; + + for (i = 0; i < BLKG_IOSTAT_NR; i++) { + dst->bytes[i] -= src->bytes[i]; + dst->ios[i] -= src->ios[i]; + } +} + +static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu) +{ + struct blkcg *blkcg = css_to_blkcg(css); + struct blkcg_gq *blkg; + + rcu_read_lock(); + + hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { + struct blkcg_gq *parent = blkg->parent; + struct blkg_iostat_set *bisc = per_cpu_ptr(blkg->iostat_cpu, cpu); + struct blkg_iostat cur, delta; + unsigned int seq; + + /* fetch the current per-cpu values */ + do { + seq = u64_stats_fetch_begin(&bisc->sync); + blkg_iostat_set(&cur, &bisc->cur); + } while (u64_stats_fetch_retry(&bisc->sync, seq)); + + /* propagate percpu delta to global */ + u64_stats_update_begin(&blkg->iostat.sync); + blkg_iostat_set(&delta, &cur); + blkg_iostat_sub(&delta, &bisc->last); + blkg_iostat_add(&blkg->iostat.cur, &delta); + blkg_iostat_add(&bisc->last, &delta); + u64_stats_update_end(&blkg->iostat.sync); + + /* propagate global delta to parent */ + if (parent) { + u64_stats_update_begin(&parent->iostat.sync); + blkg_iostat_set(&delta, &blkg->iostat.cur); + blkg_iostat_sub(&delta, &blkg->iostat.last); + blkg_iostat_add(&parent->iostat.cur, &delta); + blkg_iostat_add(&blkg->iostat.last, &delta); + u64_stats_update_end(&parent->iostat.sync); + } + } + + rcu_read_unlock(); +} + static int blkcg_print_stat(struct seq_file *sf, void *v) { struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); @@ -1086,77 +1157,6 @@ static int blkcg_can_attach(struct cgroup_taskset *tset) return ret; } -static void blkg_iostat_set(struct blkg_iostat *dst, struct blkg_iostat *src) -{ - int i; - - for (i = 0; i < BLKG_IOSTAT_NR; i++) { - dst->bytes[i] = src->bytes[i]; - dst->ios[i] = src->ios[i]; - } -} - -static void blkg_iostat_add(struct blkg_iostat *dst, struct blkg_iostat *src) -{ - int i; - - for (i = 0; i < BLKG_IOSTAT_NR; i++) { - dst->bytes[i] += src->bytes[i]; - dst->ios[i] += src->ios[i]; - } -} - -static void blkg_iostat_sub(struct blkg_iostat *dst, struct blkg_iostat *src) -{ - int i; - - for (i = 0; i < BLKG_IOSTAT_NR; i++) { - dst->bytes[i] -= src->bytes[i]; - dst->ios[i] -= src->ios[i]; - } -} - -static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu) -{ - struct blkcg *blkcg = css_to_blkcg(css); - struct blkcg_gq *blkg; - - rcu_read_lock(); - - hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { - struct blkcg_gq *parent = blkg->parent; - struct blkg_iostat_set *bisc = per_cpu_ptr(blkg->iostat_cpu, cpu); - struct blkg_iostat cur, delta; - unsigned seq; - - /* fetch the current per-cpu values */ - do { - seq = u64_stats_fetch_begin(&bisc->sync); - blkg_iostat_set(&cur, &bisc->cur); - } while (u64_stats_fetch_retry(&bisc->sync, seq)); - - /* propagate percpu delta to global */ - u64_stats_update_begin(&blkg->iostat.sync); - blkg_iostat_set(&delta, &cur); - blkg_iostat_sub(&delta, &bisc->last); - blkg_iostat_add(&blkg->iostat.cur, &delta); - blkg_iostat_add(&bisc->last, &delta); - u64_stats_update_end(&blkg->iostat.sync); - - /* propagate global delta to parent */ - if (parent) { - u64_stats_update_begin(&parent->iostat.sync); - blkg_iostat_set(&delta, &blkg->iostat.cur); - blkg_iostat_sub(&delta, &blkg->iostat.last); - blkg_iostat_add(&parent->iostat.cur, &delta); - blkg_iostat_add(&blkg->iostat.last, &delta); - u64_stats_update_end(&parent->iostat.sync); - } - } - - rcu_read_unlock(); -} - static void blkcg_bind(struct cgroup_subsys_state *root_css) { int i;