386 lines
10 KiB
C
386 lines
10 KiB
C
#ifndef _BLK_CGROUP_H
|
|
#define _BLK_CGROUP_H
|
|
/*
|
|
* Common Block IO controller cgroup interface
|
|
*
|
|
* Based on ideas and code from CFQ, CFS and BFQ:
|
|
* Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
|
|
*
|
|
* Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
|
|
* Paolo Valente <paolo.valente@unimore.it>
|
|
*
|
|
* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
|
|
* Nauman Rafique <nauman@google.com>
|
|
*/
|
|
|
|
#include <linux/cgroup.h>
|
|
#include <linux/u64_stats_sync.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/radix-tree.h>
|
|
|
|
/* Max limits for throttle policy */
|
|
#define THROTL_IOPS_MAX UINT_MAX
|
|
|
|
/* CFQ specific, out here for blkcg->cfq_weight */
|
|
#define CFQ_WEIGHT_MIN 10
|
|
#define CFQ_WEIGHT_MAX 1000
|
|
#define CFQ_WEIGHT_DEFAULT 500
|
|
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
|
|
enum blkg_rwstat_type {
|
|
BLKG_RWSTAT_READ,
|
|
BLKG_RWSTAT_WRITE,
|
|
BLKG_RWSTAT_SYNC,
|
|
BLKG_RWSTAT_ASYNC,
|
|
|
|
BLKG_RWSTAT_NR,
|
|
BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
|
|
};
|
|
|
|
struct blkcg_gq;
|
|
|
|
struct blkcg {
|
|
struct cgroup_subsys_state css;
|
|
spinlock_t lock;
|
|
|
|
struct radix_tree_root blkg_tree;
|
|
struct blkcg_gq *blkg_hint;
|
|
struct hlist_head blkg_list;
|
|
|
|
/* for policies to test whether associated blkcg has changed */
|
|
uint64_t id;
|
|
|
|
/* TODO: per-policy storage in blkcg */
|
|
unsigned int cfq_weight; /* belongs to cfq */
|
|
};
|
|
|
|
struct blkg_stat {
|
|
struct u64_stats_sync syncp;
|
|
uint64_t cnt;
|
|
};
|
|
|
|
struct blkg_rwstat {
|
|
struct u64_stats_sync syncp;
|
|
uint64_t cnt[BLKG_RWSTAT_NR];
|
|
};
|
|
|
|
/*
|
|
* A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a
|
|
* request_queue (q). This is used by blkcg policies which need to track
|
|
* information per blkcg - q pair.
|
|
*
|
|
* There can be multiple active blkcg policies and each has its private
|
|
* data on each blkg, the size of which is determined by
|
|
* blkcg_policy->pd_size. blkcg core allocates and frees such areas
|
|
* together with blkg and invokes pd_init/exit_fn() methods.
|
|
*
|
|
* Such private data must embed struct blkg_policy_data (pd) at the
|
|
* beginning and pd_size can't be smaller than pd.
|
|
*/
|
|
struct blkg_policy_data {
|
|
/* the blkg this per-policy data belongs to */
|
|
struct blkcg_gq *blkg;
|
|
|
|
/* used during policy activation */
|
|
struct list_head alloc_node;
|
|
};
|
|
|
|
/* association between a blk cgroup and a request queue */
|
|
struct blkcg_gq {
|
|
/* Pointer to the associated request_queue */
|
|
struct request_queue *q;
|
|
struct list_head q_node;
|
|
struct hlist_node blkcg_node;
|
|
struct blkcg *blkcg;
|
|
/* reference count */
|
|
int refcnt;
|
|
|
|
struct blkg_policy_data *pd[BLKCG_MAX_POLS];
|
|
|
|
struct rcu_head rcu_head;
|
|
};
|
|
|
|
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
|
|
typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);
|
|
typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
|
|
|
|
struct blkcg_policy {
|
|
int plid;
|
|
/* policy specific private data size */
|
|
size_t pd_size;
|
|
/* cgroup files for the policy */
|
|
struct cftype *cftypes;
|
|
|
|
/* operations */
|
|
blkcg_pol_init_pd_fn *pd_init_fn;
|
|
blkcg_pol_exit_pd_fn *pd_exit_fn;
|
|
blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
|
|
};
|
|
|
|
extern struct blkcg blkcg_root;
|
|
|
|
struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup);
|
|
struct blkcg *bio_blkcg(struct bio *bio);
|
|
struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q);
|
|
struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
|
|
struct request_queue *q);
|
|
int blkcg_init_queue(struct request_queue *q);
|
|
void blkcg_drain_queue(struct request_queue *q);
|
|
void blkcg_exit_queue(struct request_queue *q);
|
|
|
|
/* Blkio controller policy registration */
|
|
int blkcg_policy_register(struct blkcg_policy *pol);
|
|
void blkcg_policy_unregister(struct blkcg_policy *pol);
|
|
int blkcg_activate_policy(struct request_queue *q,
|
|
const struct blkcg_policy *pol);
|
|
void blkcg_deactivate_policy(struct request_queue *q,
|
|
const struct blkcg_policy *pol);
|
|
|
|
void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
|
|
u64 (*prfill)(struct seq_file *,
|
|
struct blkg_policy_data *, int),
|
|
const struct blkcg_policy *pol, int data,
|
|
bool show_total);
|
|
u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v);
|
|
u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
|
|
const struct blkg_rwstat *rwstat);
|
|
u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off);
|
|
u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
|
|
int off);
|
|
|
|
struct blkg_conf_ctx {
|
|
struct gendisk *disk;
|
|
struct blkcg_gq *blkg;
|
|
u64 v;
|
|
};
|
|
|
|
int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
|
|
const char *input, struct blkg_conf_ctx *ctx);
|
|
void blkg_conf_finish(struct blkg_conf_ctx *ctx);
|
|
|
|
|
|
/**
|
|
* blkg_to_pdata - get policy private data
|
|
* @blkg: blkg of interest
|
|
* @pol: policy of interest
|
|
*
|
|
* Return pointer to private data associated with the @blkg-@pol pair.
|
|
*/
|
|
static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
|
|
struct blkcg_policy *pol)
|
|
{
|
|
return blkg ? blkg->pd[pol->plid] : NULL;
|
|
}
|
|
|
|
/**
|
|
* pdata_to_blkg - get blkg associated with policy private data
|
|
* @pd: policy private data of interest
|
|
*
|
|
* @pd is policy private data. Determine the blkg it's associated with.
|
|
*/
|
|
static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
|
|
{
|
|
return pd ? pd->blkg : NULL;
|
|
}
|
|
|
|
/**
|
|
* blkg_path - format cgroup path of blkg
|
|
* @blkg: blkg of interest
|
|
* @buf: target buffer
|
|
* @buflen: target buffer length
|
|
*
|
|
* Format the path of the cgroup of @blkg into @buf.
|
|
*/
|
|
static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
|
|
{
|
|
int ret;
|
|
|
|
rcu_read_lock();
|
|
ret = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
|
|
rcu_read_unlock();
|
|
if (ret)
|
|
strncpy(buf, "<unavailable>", buflen);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* blkg_get - get a blkg reference
|
|
* @blkg: blkg to get
|
|
*
|
|
* The caller should be holding queue_lock and an existing reference.
|
|
*/
|
|
static inline void blkg_get(struct blkcg_gq *blkg)
|
|
{
|
|
lockdep_assert_held(blkg->q->queue_lock);
|
|
WARN_ON_ONCE(!blkg->refcnt);
|
|
blkg->refcnt++;
|
|
}
|
|
|
|
void __blkg_release(struct blkcg_gq *blkg);
|
|
|
|
/**
|
|
* blkg_put - put a blkg reference
|
|
* @blkg: blkg to put
|
|
*
|
|
* The caller should be holding queue_lock.
|
|
*/
|
|
static inline void blkg_put(struct blkcg_gq *blkg)
|
|
{
|
|
lockdep_assert_held(blkg->q->queue_lock);
|
|
WARN_ON_ONCE(blkg->refcnt <= 0);
|
|
if (!--blkg->refcnt)
|
|
__blkg_release(blkg);
|
|
}
|
|
|
|
/**
|
|
* blkg_stat_add - add a value to a blkg_stat
|
|
* @stat: target blkg_stat
|
|
* @val: value to add
|
|
*
|
|
* Add @val to @stat. The caller is responsible for synchronizing calls to
|
|
* this function.
|
|
*/
|
|
static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val)
|
|
{
|
|
u64_stats_update_begin(&stat->syncp);
|
|
stat->cnt += val;
|
|
u64_stats_update_end(&stat->syncp);
|
|
}
|
|
|
|
/**
|
|
* blkg_stat_read - read the current value of a blkg_stat
|
|
* @stat: blkg_stat to read
|
|
*
|
|
* Read the current value of @stat. This function can be called without
|
|
* synchroniztion and takes care of u64 atomicity.
|
|
*/
|
|
static inline uint64_t blkg_stat_read(struct blkg_stat *stat)
|
|
{
|
|
unsigned int start;
|
|
uint64_t v;
|
|
|
|
do {
|
|
start = u64_stats_fetch_begin(&stat->syncp);
|
|
v = stat->cnt;
|
|
} while (u64_stats_fetch_retry(&stat->syncp, start));
|
|
|
|
return v;
|
|
}
|
|
|
|
/**
|
|
* blkg_stat_reset - reset a blkg_stat
|
|
* @stat: blkg_stat to reset
|
|
*/
|
|
static inline void blkg_stat_reset(struct blkg_stat *stat)
|
|
{
|
|
stat->cnt = 0;
|
|
}
|
|
|
|
/**
|
|
* blkg_rwstat_add - add a value to a blkg_rwstat
|
|
* @rwstat: target blkg_rwstat
|
|
* @rw: mask of REQ_{WRITE|SYNC}
|
|
* @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,
|
|
int rw, uint64_t val)
|
|
{
|
|
u64_stats_update_begin(&rwstat->syncp);
|
|
|
|
if (rw & REQ_WRITE)
|
|
rwstat->cnt[BLKG_RWSTAT_WRITE] += val;
|
|
else
|
|
rwstat->cnt[BLKG_RWSTAT_READ] += val;
|
|
if (rw & REQ_SYNC)
|
|
rwstat->cnt[BLKG_RWSTAT_SYNC] += val;
|
|
else
|
|
rwstat->cnt[BLKG_RWSTAT_ASYNC] += val;
|
|
|
|
u64_stats_update_end(&rwstat->syncp);
|
|
}
|
|
|
|
/**
|
|
* 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 as the return value.
|
|
* This function can be called without synchronization and takes care of
|
|
* u64 atomicity.
|
|
*/
|
|
static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
|
|
{
|
|
unsigned int start;
|
|
struct blkg_rwstat tmp;
|
|
|
|
do {
|
|
start = u64_stats_fetch_begin(&rwstat->syncp);
|
|
tmp = *rwstat;
|
|
} while (u64_stats_fetch_retry(&rwstat->syncp, start));
|
|
|
|
return tmp;
|
|
}
|
|
|
|
/**
|
|
* blkg_rwstat_sum - 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_sum(struct blkg_rwstat *rwstat)
|
|
{
|
|
struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
|
|
|
|
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)
|
|
{
|
|
memset(rwstat->cnt, 0, sizeof(rwstat->cnt));
|
|
}
|
|
|
|
#else /* CONFIG_BLK_CGROUP */
|
|
|
|
struct cgroup;
|
|
|
|
struct blkg_policy_data {
|
|
};
|
|
|
|
struct blkcg_gq {
|
|
};
|
|
|
|
struct blkcg_policy {
|
|
};
|
|
|
|
static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup) { return NULL; }
|
|
static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
|
|
static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
|
|
static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
|
|
static inline void blkcg_drain_queue(struct request_queue *q) { }
|
|
static inline void blkcg_exit_queue(struct request_queue *q) { }
|
|
static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
|
|
static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
|
|
static inline int blkcg_activate_policy(struct request_queue *q,
|
|
const struct blkcg_policy *pol) { return 0; }
|
|
static inline void blkcg_deactivate_policy(struct request_queue *q,
|
|
const struct blkcg_policy *pol) { }
|
|
|
|
static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
|
|
struct blkcg_policy *pol) { return NULL; }
|
|
static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
|
|
static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
|
|
static inline void blkg_get(struct blkcg_gq *blkg) { }
|
|
static inline void blkg_put(struct blkcg_gq *blkg) { }
|
|
|
|
#endif /* CONFIG_BLK_CGROUP */
|
|
#endif /* _BLK_CGROUP_H */
|