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linux-next/block/mq-deadline-cgroup.h
Bart Van Assche 08a9ad8bf6 block/mq-deadline: Add cgroup support
Maintain statistics per cgroup and export these to user space. These
statistics are essential for verifying whether the proper I/O priorities
have been assigned to requests. An example of the statistics data with
this patch applied:

$ cat /sys/fs/cgroup/io.stat
11:2 rbytes=0 wbytes=0 rios=3 wios=0 dbytes=0 dios=0 [NONE] dispatched=0 inserted=0 merged=171 [RT] dispatched=0 inserted=0 merged=0 [BE] dispatched=0 inserted=0 merged=0 [IDLE] dispatched=0 inserted=0 merged=0
8:32 rbytes=2142720 wbytes=0 rios=105 wios=0 dbytes=0 dios=0 [NONE] dispatched=0 inserted=0 merged=171 [RT] dispatched=0 inserted=0 merged=0 [BE] dispatched=0 inserted=0 merged=0 [IDLE] dispatched=0 inserted=0 merged=0

Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210618004456.7280-16-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-21 15:03:41 -06:00

115 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#if !defined(_MQ_DEADLINE_CGROUP_H_)
#define _MQ_DEADLINE_CGROUP_H_
#include <linux/blk-cgroup.h>
struct request_queue;
/**
* struct io_stats_per_prio - I/O statistics per I/O priority class.
* @inserted: Number of inserted requests.
* @merged: Number of merged requests.
* @dispatched: Number of dispatched requests.
* @completed: Number of I/O completions.
*/
struct io_stats_per_prio {
local_t inserted;
local_t merged;
local_t dispatched;
local_t completed;
};
/* I/O statistics per I/O cgroup per I/O priority class (IOPRIO_CLASS_*). */
struct blkcg_io_stats {
struct io_stats_per_prio stats[4];
};
/**
* struct dd_blkcg - Per cgroup data.
* @cpd: blkcg_policy_data structure.
* @stats: I/O statistics.
*/
struct dd_blkcg {
struct blkcg_policy_data cpd; /* must be the first member */
struct blkcg_io_stats __percpu *stats;
};
/*
* Count one event of type 'event_type' and with I/O priority class
* 'prio_class'.
*/
#define ddcg_count(ddcg, event_type, prio_class) do { \
if (ddcg) { \
struct blkcg_io_stats *io_stats = get_cpu_ptr((ddcg)->stats); \
\
BUILD_BUG_ON(!__same_type((ddcg), struct dd_blkcg *)); \
BUILD_BUG_ON(!__same_type((prio_class), u8)); \
local_inc(&io_stats->stats[(prio_class)].event_type); \
put_cpu_ptr(io_stats); \
} \
} while (0)
/*
* Returns the total number of ddcg_count(ddcg, event_type, prio_class) calls
* across all CPUs. No locking or barriers since it is fine if the returned
* sum is slightly outdated.
*/
#define ddcg_sum(ddcg, event_type, prio) ({ \
unsigned int cpu; \
u32 sum = 0; \
\
BUILD_BUG_ON(!__same_type((ddcg), struct dd_blkcg *)); \
BUILD_BUG_ON(!__same_type((prio), u8)); \
for_each_present_cpu(cpu) \
sum += local_read(&per_cpu_ptr((ddcg)->stats, cpu)-> \
stats[(prio)].event_type); \
sum; \
})
#ifdef CONFIG_BLK_CGROUP
/**
* struct dd_blkg - Per (cgroup, request queue) data.
* @pd: blkg_policy_data structure.
*/
struct dd_blkg {
struct blkg_policy_data pd; /* must be the first member */
};
struct dd_blkcg *dd_blkcg_from_bio(struct bio *bio);
int dd_activate_policy(struct request_queue *q);
void dd_deactivate_policy(struct request_queue *q);
int __init dd_blkcg_init(void);
void __exit dd_blkcg_exit(void);
#else /* CONFIG_BLK_CGROUP */
static inline struct dd_blkcg *dd_blkcg_from_bio(struct bio *bio)
{
return NULL;
}
static inline int dd_activate_policy(struct request_queue *q)
{
return 0;
}
static inline void dd_deactivate_policy(struct request_queue *q)
{
}
static inline int dd_blkcg_init(void)
{
return 0;
}
static inline void dd_blkcg_exit(void)
{
}
#endif /* CONFIG_BLK_CGROUP */
#endif /* _MQ_DEADLINE_CGROUP_H_ */