Commit 239eeb08 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

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: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1aa0a133

block/blk-cgroup.c

+2 −3
Original line number Diff line number Diff line
@@ -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();

include/linux/blk-cgroup.h

+7 −0
Original line number Diff line number Diff line
@@ -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 *,

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