xref: /openbmc/linux/block/blk-cgroup.h (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
1 #ifndef _BLK_CGROUP_H
2 #define _BLK_CGROUP_H
3 /*
4  * Common Block IO controller cgroup interface
5  *
6  * Based on ideas and code from CFQ, CFS and BFQ:
7  * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
8  *
9  * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
10  *		      Paolo Valente <paolo.valente@unimore.it>
11  *
12  * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
13  * 	              Nauman Rafique <nauman@google.com>
14  */
15 
16 #include <linux/cgroup.h>
17 
18 #ifdef CONFIG_BLK_CGROUP
19 
20 struct blkio_cgroup {
21 	struct cgroup_subsys_state css;
22 	unsigned int weight;
23 	spinlock_t lock;
24 	struct hlist_head blkg_list;
25 };
26 
27 struct blkio_group {
28 	/* An rcu protected unique identifier for the group */
29 	void *key;
30 	struct hlist_node blkcg_node;
31 	unsigned short blkcg_id;
32 #ifdef CONFIG_DEBUG_BLK_CGROUP
33 	/* Store cgroup path */
34 	char path[128];
35 	/* How many times this group has been removed from service tree */
36 	unsigned long dequeue;
37 #endif
38 	/* The device MKDEV(major, minor), this group has been created for */
39 	dev_t   dev;
40 
41 	/* total disk time and nr sectors dispatched by this group */
42 	unsigned long time;
43 	unsigned long sectors;
44 };
45 
46 extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
47 extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
48 
49 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
50 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
51 						unsigned int weight);
52 
53 struct blkio_policy_ops {
54 	blkio_unlink_group_fn *blkio_unlink_group_fn;
55 	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
56 };
57 
58 struct blkio_policy_type {
59 	struct list_head list;
60 	struct blkio_policy_ops ops;
61 };
62 
63 /* Blkio controller policy registration */
64 extern void blkio_policy_register(struct blkio_policy_type *);
65 extern void blkio_policy_unregister(struct blkio_policy_type *);
66 
67 #else
68 
69 struct blkio_group {
70 };
71 
72 struct blkio_policy_type {
73 };
74 
75 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
76 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
77 
78 #endif
79 
80 #define BLKIO_WEIGHT_MIN	100
81 #define BLKIO_WEIGHT_MAX	1000
82 #define BLKIO_WEIGHT_DEFAULT	500
83 
84 #ifdef CONFIG_DEBUG_BLK_CGROUP
85 static inline char *blkg_path(struct blkio_group *blkg)
86 {
87 	return blkg->path;
88 }
89 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
90 				unsigned long dequeue);
91 #else
92 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
93 static inline void blkiocg_update_blkio_group_dequeue_stats(
94 			struct blkio_group *blkg, unsigned long dequeue) {}
95 #endif
96 
97 #ifdef CONFIG_BLK_CGROUP
98 extern struct blkio_cgroup blkio_root_cgroup;
99 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
100 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
101 			struct blkio_group *blkg, void *key, dev_t dev);
102 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
103 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
104 						void *key);
105 void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
106 			unsigned long time, unsigned long sectors);
107 #else
108 struct cgroup;
109 static inline struct blkio_cgroup *
110 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
111 
112 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
113 			struct blkio_group *blkg, void *key, dev_t dev)
114 {
115 }
116 
117 static inline int
118 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
119 
120 static inline struct blkio_group *
121 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
122 static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
123 			unsigned long time, unsigned long sectors)
124 {
125 }
126 #endif
127 #endif /* _BLK_CGROUP_H */
128