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authorChristoph Hellwig <hch@lst.de>2019-06-06 12:26:19 +0200
committerJens Axboe <axboe@kernel.dk>2019-06-20 10:32:34 -0600
commit239eeb085753d4356f731a773f363eb5bed4fe81 (patch)
treebba7ae13bbc54a1ac631d2d7eb9c3fb67dd6ca3c
parent1aa0a133fbabeca9e8785fb11de471841009d6d9 (diff)
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 <chaitanya.kulkarni@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-cgroup.c5
-rw-r--r--include/linux/blk-cgroup.h7
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 *,