4 * Common Block IO controller cgroup interface
6 * Based on ideas and code from CFQ, CFS and BFQ:
7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
9 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
10 * Paolo Valente <paolo.valente@unimore.it>
12 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
13 * Nauman Rafique <nauman@google.com>
16 #include <linux/cgroup.h>
18 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
20 #ifndef CONFIG_BLK_CGROUP
21 /* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
22 extern struct cgroup_subsys blkio_subsys
;
23 #define blkio_subsys_id blkio_subsys.subsys_id
35 struct cgroup_subsys_state css
;
38 struct hlist_head blkg_list
;
41 struct blkio_group_stats
{
42 /* total disk time and nr sectors dispatched by this group */
45 /* Total disk time used by IOs in ns */
46 uint64_t io_service_time
[IO_TYPE_MAX
];
47 uint64_t io_service_bytes
[IO_TYPE_MAX
]; /* Total bytes transferred */
48 /* Total IOs serviced, post merge */
49 uint64_t io_serviced
[IO_TYPE_MAX
];
50 /* Total time spent waiting in scheduler queue in ns */
51 uint64_t io_wait_time
[IO_TYPE_MAX
];
52 #ifdef CONFIG_DEBUG_BLK_CGROUP
53 /* How many times this group has been removed from service tree */
54 unsigned long dequeue
;
59 /* An rcu protected unique identifier for the group */
61 struct hlist_node blkcg_node
;
62 unsigned short blkcg_id
;
63 #ifdef CONFIG_DEBUG_BLK_CGROUP
64 /* Store cgroup path */
67 /* The device MKDEV(major, minor), this group has been created for */
70 /* Need to serialize the stats in the case of reset/update */
71 spinlock_t stats_lock
;
72 struct blkio_group_stats stats
;
75 typedef void (blkio_unlink_group_fn
) (void *key
, struct blkio_group
*blkg
);
76 typedef void (blkio_update_group_weight_fn
) (struct blkio_group
*blkg
,
79 struct blkio_policy_ops
{
80 blkio_unlink_group_fn
*blkio_unlink_group_fn
;
81 blkio_update_group_weight_fn
*blkio_update_group_weight_fn
;
84 struct blkio_policy_type
{
85 struct list_head list
;
86 struct blkio_policy_ops ops
;
89 /* Blkio controller policy registration */
90 extern void blkio_policy_register(struct blkio_policy_type
*);
91 extern void blkio_policy_unregister(struct blkio_policy_type
*);
98 struct blkio_policy_type
{
101 static inline void blkio_policy_register(struct blkio_policy_type
*blkiop
) { }
102 static inline void blkio_policy_unregister(struct blkio_policy_type
*blkiop
) { }
106 #define BLKIO_WEIGHT_MIN 100
107 #define BLKIO_WEIGHT_MAX 1000
108 #define BLKIO_WEIGHT_DEFAULT 500
110 #ifdef CONFIG_DEBUG_BLK_CGROUP
111 static inline char *blkg_path(struct blkio_group
*blkg
)
115 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group
*blkg
,
116 unsigned long dequeue
);
118 static inline char *blkg_path(struct blkio_group
*blkg
) { return NULL
; }
119 static inline void blkiocg_update_blkio_group_dequeue_stats(
120 struct blkio_group
*blkg
, unsigned long dequeue
) {}
123 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
124 extern struct blkio_cgroup blkio_root_cgroup
;
125 extern struct blkio_cgroup
*cgroup_to_blkio_cgroup(struct cgroup
*cgroup
);
126 extern void blkiocg_add_blkio_group(struct blkio_cgroup
*blkcg
,
127 struct blkio_group
*blkg
, void *key
, dev_t dev
);
128 extern int blkiocg_del_blkio_group(struct blkio_group
*blkg
);
129 extern struct blkio_group
*blkiocg_lookup_group(struct blkio_cgroup
*blkcg
,
131 void blkiocg_update_timeslice_used(struct blkio_group
*blkg
,
135 static inline struct blkio_cgroup
*
136 cgroup_to_blkio_cgroup(struct cgroup
*cgroup
) { return NULL
; }
138 static inline void blkiocg_add_blkio_group(struct blkio_cgroup
*blkcg
,
139 struct blkio_group
*blkg
, void *key
, dev_t dev
)
144 blkiocg_del_blkio_group(struct blkio_group
*blkg
) { return 0; }
146 static inline struct blkio_group
*
147 blkiocg_lookup_group(struct blkio_cgroup
*blkcg
, void *key
) { return NULL
; }
148 static inline void blkiocg_update_timeslice_used(struct blkio_group
*blkg
,
149 unsigned long time
) {}
151 #endif /* _BLK_CGROUP_H */