Commit 362b8c16 authored by Jason Yan's avatar Jason Yan Committed by Jens Axboe
Browse files

blk-cgroup: factor out blkcg_iostat_update() 



To reduce some duplicated code, factor out blkcg_iostat_update(). No
functional change.

Signed-off-by: default avatarJason Yan <yanaijie@huawei.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220629070917.3113016-2-yanaijie@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 22d0c408

block/blk-cgroup.c

+20 −17
Original line number Diff line number Diff line
@@ -846,6 +846,21 @@ static void blkg_iostat_sub(struct blkg_iostat *dst, struct blkg_iostat *src) 
	}

}



static void blkcg_iostat_update(struct blkcg_gq *blkg, struct blkg_iostat *cur,

				struct blkg_iostat *last)

{

	struct blkg_iostat delta;

	unsigned long flags;



	/* propagate percpu delta to global */

	flags = u64_stats_update_begin_irqsave(&blkg->iostat.sync);

	blkg_iostat_set(&delta, cur);

	blkg_iostat_sub(&delta, last);

	blkg_iostat_add(&blkg->iostat.cur, &delta);

	blkg_iostat_add(last, &delta);

	u64_stats_update_end_irqrestore(&blkg->iostat.sync, flags);

}



static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu)

{

	struct blkcg *blkcg = css_to_blkcg(css);
@@ -860,8 +875,7 @@ static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu) 
	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 long flags;

		struct blkg_iostat cur;

		unsigned int seq;



		/* fetch the current per-cpu values */
@@ -870,23 +884,12 @@ static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu) 
			blkg_iostat_set(&cur, &bisc->cur);

		} while (u64_stats_fetch_retry(&bisc->sync, seq));



		/* propagate percpu delta to global */

		flags = u64_stats_update_begin_irqsave(&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_irqrestore(&blkg->iostat.sync, flags);

		blkcg_iostat_update(blkg, &cur, &bisc->last);



		/* propagate global delta to parent (unless that's root) */

		if (parent && parent->parent) {

			flags = u64_stats_update_begin_irqsave(&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_irqrestore(&parent->iostat.sync, flags);

		}

		if (parent && parent->parent)

			blkcg_iostat_update(parent, &blkg->iostat.cur,

					    &blkg->iostat.last);

	}



	rcu_read_unlock();