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/* SPDX-License-Identifier: GPL-2.0
*
* Legacy blkg rwstat helpers enabled by CONFIG_BLK_CGROUP_RWSTAT.
* Do not use in new code.
*/
#ifndef _BLK_CGROUP_RWSTAT_H
#define _BLK_CGROUP_RWSTAT_H
#include <linux/blk-cgroup.h>
enum blkg_rwstat_type {
BLKG_RWSTAT_READ,
BLKG_RWSTAT_WRITE,
BLKG_RWSTAT_SYNC,
BLKG_RWSTAT_ASYNC,
BLKG_RWSTAT_DISCARD,
BLKG_RWSTAT_NR,
BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
};
/*
* blkg_[rw]stat->aux_cnt is excluded for local stats but included for
* recursive. Used to carry stats of dead children.
*/
struct blkg_rwstat {
struct percpu_counter cpu_cnt[BLKG_RWSTAT_NR];
atomic64_t aux_cnt[BLKG_RWSTAT_NR];
};
struct blkg_rwstat_sample {
u64 cnt[BLKG_RWSTAT_NR];
};
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]);
}
int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp);
void blkg_rwstat_exit(struct blkg_rwstat *rwstat);
u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
const struct blkg_rwstat_sample *rwstat);
u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
int off);
void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
int off, struct blkg_rwstat_sample *sum);
/**
* blkg_rwstat_add - add a value to a blkg_rwstat
* @rwstat: target blkg_rwstat
* @op: REQ_OP and flags
* @val: value to add
*
* Add @val to @rwstat. The counters are chosen according to @rw. The
* caller is responsible for synchronizing calls to this function.
*/
static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
unsigned int op, uint64_t val)
{
struct percpu_counter *cnt;
if (op_is_discard(op))
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_DISCARD];
else if (op_is_write(op))
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_WRITE];
else
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ];
percpu_counter_add_batch(cnt, val, BLKG_STAT_CPU_BATCH);
if (op_is_sync(op))
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_SYNC];
else
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_ASYNC];
percpu_counter_add_batch(cnt, val, BLKG_STAT_CPU_BATCH);
}
/**
* blkg_rwstat_read - read the current values of a blkg_rwstat
* @rwstat: blkg_rwstat to read
*
* Read the current snapshot of @rwstat and return it in the aux counts.
*/
static inline void blkg_rwstat_read(struct blkg_rwstat *rwstat,
struct blkg_rwstat_sample *result)
{
int i;
for (i = 0; i < BLKG_RWSTAT_NR; i++)
result->cnt[i] =
percpu_counter_sum_positive(&rwstat->cpu_cnt[i]);
}
/**
* blkg_rwstat_total - read the total count of a blkg_rwstat
* @rwstat: blkg_rwstat to read
*
* Return the total count of @rwstat regardless of the IO direction. This
* function can be called without synchronization and takes care of u64
* atomicity.
*/
static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat)
{
struct blkg_rwstat_sample tmp = { };
blkg_rwstat_read(rwstat, &tmp);
return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE];
}
/**
* blkg_rwstat_reset - reset a blkg_rwstat
* @rwstat: blkg_rwstat to reset
*/
static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
{
int i;
for (i = 0; i < BLKG_RWSTAT_NR; i++) {
percpu_counter_set(&rwstat->cpu_cnt[i], 0);
atomic64_set(&rwstat->aux_cnt[i], 0);
}
}
/**
* blkg_rwstat_add_aux - add a blkg_rwstat into another's aux count
* @to: the destination blkg_rwstat
* @from: the source
*
* Add @from's count including the aux one to @to's aux count.
*/
static inline void blkg_rwstat_add_aux(struct blkg_rwstat *to,
struct blkg_rwstat *from)
{
u64 sum[BLKG_RWSTAT_NR];
int i;
for (i = 0; i < BLKG_RWSTAT_NR; i++)
sum[i] = percpu_counter_sum_positive(&from->cpu_cnt[i]);
for (i = 0; i < BLKG_RWSTAT_NR; i++)
atomic64_add(sum[i] + atomic64_read(&from->aux_cnt[i]),
&to->aux_cnt[i]);
}
#endif /* _BLK_CGROUP_RWSTAT_H */
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