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
27 struct cgroup_subsys_state css
;
30 struct hlist_head blkg_list
;
34 /* An rcu protected unique identifier for the group */
36 struct hlist_node blkcg_node
;
37 unsigned short blkcg_id
;
38 #ifdef CONFIG_DEBUG_BLK_CGROUP
39 /* Store cgroup path */
41 /* How many times this group has been removed from service tree */
42 unsigned long dequeue
;
44 /* The device MKDEV(major, minor), this group has been created for */
47 /* total disk time and nr sectors dispatched by this group */
49 unsigned long sectors
;
52 typedef void (blkio_unlink_group_fn
) (void *key
, struct blkio_group
*blkg
);
53 typedef void (blkio_update_group_weight_fn
) (struct blkio_group
*blkg
,
56 struct blkio_policy_ops
{
57 blkio_unlink_group_fn
*blkio_unlink_group_fn
;
58 blkio_update_group_weight_fn
*blkio_update_group_weight_fn
;
61 struct blkio_policy_type
{
62 struct list_head list
;
63 struct blkio_policy_ops ops
;
66 /* Blkio controller policy registration */
67 extern void blkio_policy_register(struct blkio_policy_type
*);
68 extern void blkio_policy_unregister(struct blkio_policy_type
*);
75 struct blkio_policy_type
{
78 static inline void blkio_policy_register(struct blkio_policy_type
*blkiop
) { }
79 static inline void blkio_policy_unregister(struct blkio_policy_type
*blkiop
) { }
83 #define BLKIO_WEIGHT_MIN 100
84 #define BLKIO_WEIGHT_MAX 1000
85 #define BLKIO_WEIGHT_DEFAULT 500
87 #ifdef CONFIG_DEBUG_BLK_CGROUP
88 static inline char *blkg_path(struct blkio_group
*blkg
)
92 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group
*blkg
,
93 unsigned long dequeue
);
95 static inline char *blkg_path(struct blkio_group
*blkg
) { return NULL
; }
96 static inline void blkiocg_update_blkio_group_dequeue_stats(
97 struct blkio_group
*blkg
, unsigned long dequeue
) {}
100 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
101 extern struct blkio_cgroup blkio_root_cgroup
;
102 extern struct blkio_cgroup
*cgroup_to_blkio_cgroup(struct cgroup
*cgroup
);
103 extern void blkiocg_add_blkio_group(struct blkio_cgroup
*blkcg
,
104 struct blkio_group
*blkg
, void *key
, dev_t dev
);
105 extern int blkiocg_del_blkio_group(struct blkio_group
*blkg
);
106 extern struct blkio_group
*blkiocg_lookup_group(struct blkio_cgroup
*blkcg
,
108 void blkiocg_update_blkio_group_stats(struct blkio_group
*blkg
,
112 static inline struct blkio_cgroup
*
113 cgroup_to_blkio_cgroup(struct cgroup
*cgroup
) { return NULL
; }
115 static inline void blkiocg_add_blkio_group(struct blkio_cgroup
*blkcg
,
116 struct blkio_group
*blkg
, void *key
, dev_t dev
)
121 blkiocg_del_blkio_group(struct blkio_group
*blkg
) { return 0; }
123 static inline struct blkio_group
*
124 blkiocg_lookup_group(struct blkio_cgroup
*blkcg
, void *key
) { return NULL
; }
125 static inline void blkiocg_update_blkio_group_stats(struct blkio_group
*blkg
,
126 unsigned long time
) {}
128 #endif /* _BLK_CGROUP_H */