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 enum blkio_policy_id {
19 BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
22 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
24 #ifndef CONFIG_BLK_CGROUP
25 /* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
26 extern struct cgroup_subsys blkio_subsys;
27 #define blkio_subsys_id blkio_subsys.subsys_id
31 /* Total time spent (in ns) between request dispatch to the driver and
32 * request completion for IOs doen by this cgroup. This may not be
33 * accurate when NCQ is turned on. */
34 BLKIO_STAT_SERVICE_TIME = 0,
35 /* Total bytes transferred */
36 BLKIO_STAT_SERVICE_BYTES,
37 /* Total IOs serviced, post merge */
39 /* Total time spent waiting in scheduler queue in ns */
41 /* Number of IOs merged */
43 /* Number of IOs queued up */
45 /* All the single valued stats go below this */
48 #ifdef CONFIG_DEBUG_BLK_CGROUP
49 BLKIO_STAT_AVG_QUEUE_SIZE,
51 BLKIO_STAT_EMPTY_TIME,
52 BLKIO_STAT_GROUP_WAIT_TIME,
65 /* blkg state flags */
66 enum blkg_state_flags {
72 /* cgroup files owned by proportional weight policy */
73 enum blkcg_file_name_prop {
74 BLKIO_PROP_weight = 1,
75 BLKIO_PROP_weight_device,
76 BLKIO_PROP_io_service_bytes,
77 BLKIO_PROP_io_serviced,
80 BLKIO_PROP_io_service_time,
81 BLKIO_PROP_io_wait_time,
84 BLKIO_PROP_avg_queue_size,
85 BLKIO_PROP_group_wait_time,
87 BLKIO_PROP_empty_time,
92 struct cgroup_subsys_state css;
95 struct hlist_head blkg_list;
96 struct list_head policy_list; /* list of blkio_policy_node */
99 struct blkio_group_stats {
100 /* total disk time and nr sectors dispatched by this group */
103 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
104 #ifdef CONFIG_DEBUG_BLK_CGROUP
105 /* Sum of number of IOs queued across all samples */
106 uint64_t avg_queue_size_sum;
107 /* Count of samples taken for average */
108 uint64_t avg_queue_size_samples;
109 /* How many times this group has been removed from service tree */
110 unsigned long dequeue;
112 /* Total time spent waiting for it to be assigned a timeslice. */
113 uint64_t group_wait_time;
114 uint64_t start_group_wait_time;
116 /* Time spent idling for this blkio_group */
118 uint64_t start_idle_time;
120 * Total time when we have requests queued and do not contain the
121 * current active queue.
124 uint64_t start_empty_time;
130 /* An rcu protected unique identifier for the group */
132 struct hlist_node blkcg_node;
133 unsigned short blkcg_id;
134 /* Store cgroup path */
136 /* The device MKDEV(major, minor), this group has been created for */
138 /* policy which owns this blk group */
139 enum blkio_policy_id plid;
141 /* Need to serialize the stats in the case of reset/update */
142 spinlock_t stats_lock;
143 struct blkio_group_stats stats;
146 struct blkio_policy_node {
147 struct list_head node;
150 /* This node belongs to max bw policy or porportional weight policy */
151 enum blkio_policy_id plid;
152 /* cgroup file to which this rule belongs to */
156 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
159 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
160 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
161 unsigned int weight);
163 struct blkio_policy_ops {
164 blkio_unlink_group_fn *blkio_unlink_group_fn;
165 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
168 struct blkio_policy_type {
169 struct list_head list;
170 struct blkio_policy_ops ops;
171 enum blkio_policy_id plid;
174 /* Blkio controller policy registration */
175 extern void blkio_policy_register(struct blkio_policy_type *);
176 extern void blkio_policy_unregister(struct blkio_policy_type *);
178 static inline char *blkg_path(struct blkio_group *blkg)
188 struct blkio_policy_type {
191 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
192 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
194 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
198 #define BLKIO_WEIGHT_MIN 100
199 #define BLKIO_WEIGHT_MAX 1000
200 #define BLKIO_WEIGHT_DEFAULT 500
202 #ifdef CONFIG_DEBUG_BLK_CGROUP
203 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
204 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
205 unsigned long dequeue);
206 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
207 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
208 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
210 #define BLKG_FLAG_FNS(name) \
211 static inline void blkio_mark_blkg_##name( \
212 struct blkio_group_stats *stats) \
214 stats->flags |= (1 << BLKG_##name); \
216 static inline void blkio_clear_blkg_##name( \
217 struct blkio_group_stats *stats) \
219 stats->flags &= ~(1 << BLKG_##name); \
221 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
223 return (stats->flags & (1 << BLKG_##name)) != 0; \
226 BLKG_FLAG_FNS(waiting)
227 BLKG_FLAG_FNS(idling)
231 static inline void blkiocg_update_avg_queue_size_stats(
232 struct blkio_group *blkg) {}
233 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
234 unsigned long dequeue) {}
235 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
237 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
238 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
241 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
242 extern struct blkio_cgroup blkio_root_cgroup;
243 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
244 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
245 struct blkio_group *blkg, void *key, dev_t dev,
246 enum blkio_policy_id plid);
247 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
248 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
250 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
252 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
253 bool direction, bool sync);
254 void blkiocg_update_completion_stats(struct blkio_group *blkg,
255 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
256 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
258 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
259 struct blkio_group *curr_blkg, bool direction, bool sync);
260 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
261 bool direction, bool sync);
264 static inline struct blkio_cgroup *
265 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
267 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
268 struct blkio_group *blkg, void *key, dev_t dev,
269 enum blkio_policy_id plid) {}
272 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
274 static inline struct blkio_group *
275 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
276 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
277 unsigned long time) {}
278 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
279 uint64_t bytes, bool direction, bool sync) {}
280 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
281 uint64_t start_time, uint64_t io_start_time, bool direction,
283 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
284 bool direction, bool sync) {}
285 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
286 struct blkio_group *curr_blkg, bool direction, bool sync) {}
287 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
288 bool direction, bool sync) {}
290 #endif /* _BLK_CGROUP_H */