Commit 5d0b6e48 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-cgroup: pass blkg_rwstat structures by reference 



Returning a structure generates rather bad code, so switch to passing
by reference.  Also don't require the structure to be zeroed and add
to the 0-initialized counters, but actually set the counters to the
calculated value.

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 239eeb08

block/bfq-cgroup.c

+9 −6
Original line number Diff line number Diff line
@@ -935,9 +935,9 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, 
static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf,

					struct blkg_policy_data *pd, int off)

{

	struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd),

							   &blkcg_policy_bfq,

							   off);

	struct blkg_rwstat sum;



	blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum);

	return __blkg_prfill_rwstat(sf, pd, &sum);

}
@@ -975,9 +975,12 @@ static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) 
static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf,

					 struct blkg_policy_data *pd, int off)

{

	struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL,

					offsetof(struct blkcg_gq, stat_bytes));

	u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +

	struct blkg_rwstat tmp;

	u64 sum;



	blkg_rwstat_recursive_sum(pd->blkg, NULL,

			offsetof(struct blkcg_gq, stat_bytes), &tmp);

	sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +

		atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);



	return __blkg_prfill_u64(sf, pd, sum >> 9);

block/blk-cgroup.c

+16 −15
Original line number Diff line number Diff line
@@ -597,8 +597,9 @@ EXPORT_SYMBOL_GPL(blkg_prfill_stat); 
u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,

		       int off)

{

	struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd + off);

	struct blkg_rwstat rwstat = { };



	blkg_rwstat_read((void *)pd + off, &rwstat);

	return __blkg_prfill_rwstat(sf, pd, &rwstat);

}

EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
@@ -606,8 +607,9 @@ EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); 
static u64 blkg_prfill_rwstat_field(struct seq_file *sf,

				    struct blkg_policy_data *pd, int off)

{

	struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd->blkg + off);

	struct blkg_rwstat rwstat = { };



	blkg_rwstat_read((void *)pd->blkg + off, &rwstat);

	return __blkg_prfill_rwstat(sf, pd, &rwstat);

}
@@ -649,8 +651,9 @@ static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf, 
					      struct blkg_policy_data *pd,

					      int off)

{

	struct blkg_rwstat rwstat = blkg_rwstat_recursive_sum(pd->blkg,

							      NULL, off);

	struct blkg_rwstat rwstat;



	blkg_rwstat_recursive_sum(pd->blkg, NULL, off, &rwstat);

	return __blkg_prfill_rwstat(sf, pd, &rwstat);

}
@@ -731,6 +734,7 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum); 
 * @blkg: blkg of interest

 * @pol: blkcg_policy which contains the blkg_rwstat

 * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg

 * @sum: blkg_rwstat structure containing the results

 *

 * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its

 * online descendants and their aux counts.  The caller must be holding the
@@ -739,12 +743,11 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum); 
 * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it

 * is at @off bytes into @blkg's blkg_policy_data of the policy.

 */

struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,

					     struct blkcg_policy *pol, int off)

void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,

		int off, struct blkg_rwstat *sum)

{

	struct blkcg_gq *pos_blkg;

	struct cgroup_subsys_state *pos_css;

	struct blkg_rwstat sum = { };

	unsigned int i;



	lockdep_assert_held(&blkg->q->queue_lock);
@@ -762,12 +765,10 @@ 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(blkg_rwstat_read_counter(rwstat, i),

				&sum.aux_cnt[i]);

			atomic64_set(&sum->aux_cnt[i],

				blkg_rwstat_read_counter(rwstat, i));

	}

	rcu_read_unlock();



	return sum;

}

EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);
@@ -953,14 +954,14 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) 


		spin_lock_irq(&blkg->q->queue_lock);



		rwstat = blkg_rwstat_recursive_sum(blkg, NULL,

					offsetof(struct blkcg_gq, stat_bytes));

		blkg_rwstat_recursive_sum(blkg, NULL,

				offsetof(struct blkcg_gq, stat_bytes), &rwstat);

		rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);

		wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);

		dbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);



		rwstat = blkg_rwstat_recursive_sum(blkg, NULL,

					offsetof(struct blkcg_gq, stat_ios));

		blkg_rwstat_recursive_sum(blkg, NULL,

					offsetof(struct blkcg_gq, stat_ios), &rwstat);

		rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);

		wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);

		dios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);

include/linux/blk-cgroup.h

+7 −7
Original line number Diff line number Diff line
@@ -224,8 +224,8 @@ int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v); 


u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,

			    struct blkcg_policy *pol, int off);

struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,

					     struct blkcg_policy *pol, int off);

void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,

		int off, struct blkg_rwstat *sum);



struct blkg_conf_ctx {

	struct gendisk			*disk;
@@ -700,15 +700,14 @@ static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, 
 *

 * Read the current snapshot of @rwstat and return it in the aux counts.

 */

static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)

static inline void blkg_rwstat_read(struct blkg_rwstat *rwstat,

		struct blkg_rwstat *result)

{

	struct blkg_rwstat result;

	int i;



	for (i = 0; i < BLKG_RWSTAT_NR; i++)

		atomic64_set(&result.aux_cnt[i],

		atomic64_set(&result->aux_cnt[i],

			     percpu_counter_sum_positive(&rwstat->cpu_cnt[i]));

	return result;

}



/**
@@ -721,8 +720,9 @@ static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) 
 */

static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat)

{

	struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);

	struct blkg_rwstat tmp = { };



	blkg_rwstat_read(rwstat, &tmp);

	return atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +

		atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);

}

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