From 239eeb085753d4356f731a773f363eb5bed4fe81 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 6 Jun 2019 12:26:19 +0200 Subject: [PATCH] blk-cgroup: factor out a helper to read rwstat counter Trying to break up the crazy statements to something readable. Also switch to an unsigned counter as it can't ever turn negative. Reviewed-by: Chaitanya Kulkarni Acked-by: Tejun Heo Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 5 ++--- include/linux/blk-cgroup.h | 7 +++++++ 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 440797293235..0778e52b1db2 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -745,7 +745,7 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_gq *pos_blkg; struct cgroup_subsys_state *pos_css; struct blkg_rwstat sum = { }; - int i; + unsigned int i; lockdep_assert_held(&blkg->q->queue_lock); @@ -762,8 +762,7 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, rwstat = (void *)pos_blkg + off; for (i = 0; i < BLKG_RWSTAT_NR; i++) - atomic64_add(atomic64_read(&rwstat->aux_cnt[i]) + - percpu_counter_sum_positive(&rwstat->cpu_cnt[i]), + atomic64_add(blkg_rwstat_read_counter(rwstat, i), &sum.aux_cnt[i]); } rcu_read_unlock(); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 76c61318fda5..06236f56a840 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -198,6 +198,13 @@ int blkcg_activate_policy(struct request_queue *q, void blkcg_deactivate_policy(struct request_queue *q, const struct blkcg_policy *pol); +static inline u64 blkg_rwstat_read_counter(struct blkg_rwstat *rwstat, + unsigned int idx) +{ + return atomic64_read(&rwstat->aux_cnt[idx]) + + percpu_counter_sum_positive(&rwstat->cpu_cnt[idx]); +} + const char *blkg_dev_name(struct blkcg_gq *blkg); void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, u64 (*prfill)(struct seq_file *, -- 2.30.2