Trying to break up the crazy statements to something readable. Also switch to an unsigned counter as it can't ever turn negative.
Signed-off-by: Christoph Hellwig <[email protected]> --- 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 b97b479e4f64..6f79ace02be4 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -750,7 +750,7 @@ 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); @@ -767,8 +767,7 @@ 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 *, -- 2.20.1
