ceph: correctly set 'follows' in flushsnap messages
[linux-2.6.git] / block / blk-cgroup.h
blob2b866ec1dcea668ffad0ba4c3499987cc75d0e6b
1 #ifndef _BLK_CGROUP_H
2 #define _BLK_CGROUP_H
3 /*
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
24 #endif
26 enum stat_type {
27 /* Total time spent (in ns) between request dispatch to the driver and
28 * request completion for IOs doen by this cgroup. This may not be
29 * accurate when NCQ is turned on. */
30 BLKIO_STAT_SERVICE_TIME = 0,
31 /* Total bytes transferred */
32 BLKIO_STAT_SERVICE_BYTES,
33 /* Total IOs serviced, post merge */
34 BLKIO_STAT_SERVICED,
35 /* Total time spent waiting in scheduler queue in ns */
36 BLKIO_STAT_WAIT_TIME,
37 /* Number of IOs merged */
38 BLKIO_STAT_MERGED,
39 /* Number of IOs queued up */
40 BLKIO_STAT_QUEUED,
41 /* All the single valued stats go below this */
42 BLKIO_STAT_TIME,
43 BLKIO_STAT_SECTORS,
44 #ifdef CONFIG_DEBUG_BLK_CGROUP
45 BLKIO_STAT_AVG_QUEUE_SIZE,
46 BLKIO_STAT_IDLE_TIME,
47 BLKIO_STAT_EMPTY_TIME,
48 BLKIO_STAT_GROUP_WAIT_TIME,
49 BLKIO_STAT_DEQUEUE
50 #endif
53 enum stat_sub_type {
54 BLKIO_STAT_READ = 0,
55 BLKIO_STAT_WRITE,
56 BLKIO_STAT_SYNC,
57 BLKIO_STAT_ASYNC,
58 BLKIO_STAT_TOTAL
61 /* blkg state flags */
62 enum blkg_state_flags {
63 BLKG_waiting = 0,
64 BLKG_idling,
65 BLKG_empty,
68 struct blkio_cgroup {
69 struct cgroup_subsys_state css;
70 unsigned int weight;
71 spinlock_t lock;
72 struct hlist_head blkg_list;
73 struct list_head policy_list; /* list of blkio_policy_node */
76 struct blkio_group_stats {
77 /* total disk time and nr sectors dispatched by this group */
78 uint64_t time;
79 uint64_t sectors;
80 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
81 #ifdef CONFIG_DEBUG_BLK_CGROUP
82 /* Sum of number of IOs queued across all samples */
83 uint64_t avg_queue_size_sum;
84 /* Count of samples taken for average */
85 uint64_t avg_queue_size_samples;
86 /* How many times this group has been removed from service tree */
87 unsigned long dequeue;
89 /* Total time spent waiting for it to be assigned a timeslice. */
90 uint64_t group_wait_time;
91 uint64_t start_group_wait_time;
93 /* Time spent idling for this blkio_group */
94 uint64_t idle_time;
95 uint64_t start_idle_time;
97 * Total time when we have requests queued and do not contain the
98 * current active queue.
100 uint64_t empty_time;
101 uint64_t start_empty_time;
102 uint16_t flags;
103 #endif
106 struct blkio_group {
107 /* An rcu protected unique identifier for the group */
108 void *key;
109 struct hlist_node blkcg_node;
110 unsigned short blkcg_id;
111 /* Store cgroup path */
112 char path[128];
113 /* The device MKDEV(major, minor), this group has been created for */
114 dev_t dev;
116 /* Need to serialize the stats in the case of reset/update */
117 spinlock_t stats_lock;
118 struct blkio_group_stats stats;
121 struct blkio_policy_node {
122 struct list_head node;
123 dev_t dev;
124 unsigned int weight;
127 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
128 dev_t dev);
130 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
131 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
132 unsigned int weight);
134 struct blkio_policy_ops {
135 blkio_unlink_group_fn *blkio_unlink_group_fn;
136 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
139 struct blkio_policy_type {
140 struct list_head list;
141 struct blkio_policy_ops ops;
144 /* Blkio controller policy registration */
145 extern void blkio_policy_register(struct blkio_policy_type *);
146 extern void blkio_policy_unregister(struct blkio_policy_type *);
148 static inline char *blkg_path(struct blkio_group *blkg)
150 return blkg->path;
153 #else
155 struct blkio_group {
158 struct blkio_policy_type {
161 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
162 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
164 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
166 #endif
168 #define BLKIO_WEIGHT_MIN 100
169 #define BLKIO_WEIGHT_MAX 1000
170 #define BLKIO_WEIGHT_DEFAULT 500
172 #ifdef CONFIG_DEBUG_BLK_CGROUP
173 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
174 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
175 unsigned long dequeue);
176 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
177 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
178 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
180 #define BLKG_FLAG_FNS(name) \
181 static inline void blkio_mark_blkg_##name( \
182 struct blkio_group_stats *stats) \
184 stats->flags |= (1 << BLKG_##name); \
186 static inline void blkio_clear_blkg_##name( \
187 struct blkio_group_stats *stats) \
189 stats->flags &= ~(1 << BLKG_##name); \
191 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
193 return (stats->flags & (1 << BLKG_##name)) != 0; \
196 BLKG_FLAG_FNS(waiting)
197 BLKG_FLAG_FNS(idling)
198 BLKG_FLAG_FNS(empty)
199 #undef BLKG_FLAG_FNS
200 #else
201 static inline void blkiocg_update_avg_queue_size_stats(
202 struct blkio_group *blkg) {}
203 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
204 unsigned long dequeue) {}
205 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
207 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
208 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
209 #endif
211 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
212 extern struct blkio_cgroup blkio_root_cgroup;
213 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
214 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
215 struct blkio_group *blkg, void *key, dev_t dev);
216 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
217 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
218 void *key);
219 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
220 unsigned long time);
221 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
222 bool direction, bool sync);
223 void blkiocg_update_completion_stats(struct blkio_group *blkg,
224 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
225 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
226 bool sync);
227 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
228 struct blkio_group *curr_blkg, bool direction, bool sync);
229 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
230 bool direction, bool sync);
231 #else
232 struct cgroup;
233 static inline struct blkio_cgroup *
234 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
236 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
237 struct blkio_group *blkg, void *key, dev_t dev) {}
239 static inline int
240 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
242 static inline struct blkio_group *
243 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
244 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
245 unsigned long time) {}
246 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
247 uint64_t bytes, bool direction, bool sync) {}
248 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
249 uint64_t start_time, uint64_t io_start_time, bool direction,
250 bool sync) {}
251 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
252 bool direction, bool sync) {}
253 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
254 struct blkio_group *curr_blkg, bool direction, bool sync) {}
255 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
256 bool direction, bool sync) {}
257 #endif
258 #endif /* _BLK_CGROUP_H */