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 */
20 BLKIO_POLICY_THROTL, /* Throttling */
23 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
25 #ifndef CONFIG_BLK_CGROUP
26 /* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
27 extern struct cgroup_subsys blkio_subsys;
28 #define blkio_subsys_id blkio_subsys.subsys_id
32 /* Total time spent (in ns) between request dispatch to the driver and
33 * request completion for IOs doen by this cgroup. This may not be
34 * accurate when NCQ is turned on. */
35 BLKIO_STAT_SERVICE_TIME = 0,
36 /* Total bytes transferred */
37 BLKIO_STAT_SERVICE_BYTES,
38 /* Total IOs serviced, post merge */
40 /* Total time spent waiting in scheduler queue in ns */
42 /* Number of IOs merged */
44 /* Number of IOs queued up */
46 /* All the single valued stats go below this */
49 #ifdef CONFIG_DEBUG_BLK_CGROUP
50 BLKIO_STAT_AVG_QUEUE_SIZE,
52 BLKIO_STAT_EMPTY_TIME,
53 BLKIO_STAT_GROUP_WAIT_TIME,
66 /* blkg state flags */
67 enum blkg_state_flags {
73 /* cgroup files owned by proportional weight policy */
74 enum blkcg_file_name_prop {
75 BLKIO_PROP_weight = 1,
76 BLKIO_PROP_weight_device,
77 BLKIO_PROP_io_service_bytes,
78 BLKIO_PROP_io_serviced,
81 BLKIO_PROP_io_service_time,
82 BLKIO_PROP_io_wait_time,
85 BLKIO_PROP_avg_queue_size,
86 BLKIO_PROP_group_wait_time,
88 BLKIO_PROP_empty_time,
92 /* cgroup files owned by throttle policy */
93 enum blkcg_file_name_throtl {
94 BLKIO_THROTL_read_bps_device,
95 BLKIO_THROTL_write_bps_device,
96 BLKIO_THROTL_read_iops_device,
97 BLKIO_THROTL_write_iops_device,
98 BLKIO_THROTL_io_service_bytes,
99 BLKIO_THROTL_io_serviced,
102 struct blkio_cgroup {
103 struct cgroup_subsys_state css;
106 struct hlist_head blkg_list;
107 struct list_head policy_list; /* list of blkio_policy_node */
110 struct blkio_group_stats {
111 /* total disk time and nr sectors dispatched by this group */
114 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
115 #ifdef CONFIG_DEBUG_BLK_CGROUP
116 /* Sum of number of IOs queued across all samples */
117 uint64_t avg_queue_size_sum;
118 /* Count of samples taken for average */
119 uint64_t avg_queue_size_samples;
120 /* How many times this group has been removed from service tree */
121 unsigned long dequeue;
123 /* Total time spent waiting for it to be assigned a timeslice. */
124 uint64_t group_wait_time;
125 uint64_t start_group_wait_time;
127 /* Time spent idling for this blkio_group */
129 uint64_t start_idle_time;
131 * Total time when we have requests queued and do not contain the
132 * current active queue.
135 uint64_t start_empty_time;
141 /* An rcu protected unique identifier for the group */
143 struct hlist_node blkcg_node;
144 unsigned short blkcg_id;
145 /* Store cgroup path */
147 /* The device MKDEV(major, minor), this group has been created for */
149 /* policy which owns this blk group */
150 enum blkio_policy_id plid;
152 /* Need to serialize the stats in the case of reset/update */
153 spinlock_t stats_lock;
154 struct blkio_group_stats stats;
157 struct blkio_policy_node {
158 struct list_head node;
160 /* This node belongs to max bw policy or porportional weight policy */
161 enum blkio_policy_id plid;
162 /* cgroup file to which this rule belongs to */
168 * Rate read/write in terms of byptes per second
169 * Whether this rate represents read or write is determined
170 * by file type "fileid".
177 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
179 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
181 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
183 extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
185 extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
188 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
189 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
190 unsigned int weight);
191 typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
193 typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
195 typedef void (blkio_update_group_read_iops_fn) (struct blkio_group *blkg,
196 unsigned int read_iops);
197 typedef void (blkio_update_group_write_iops_fn) (struct blkio_group *blkg,
198 unsigned int write_iops);
200 struct blkio_policy_ops {
201 blkio_unlink_group_fn *blkio_unlink_group_fn;
202 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
203 blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
204 blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
205 blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
206 blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
209 struct blkio_policy_type {
210 struct list_head list;
211 struct blkio_policy_ops ops;
212 enum blkio_policy_id plid;
215 /* Blkio controller policy registration */
216 extern void blkio_policy_register(struct blkio_policy_type *);
217 extern void blkio_policy_unregister(struct blkio_policy_type *);
219 static inline char *blkg_path(struct blkio_group *blkg)
229 struct blkio_policy_type {
232 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
233 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
235 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
239 #define BLKIO_WEIGHT_MIN 100
240 #define BLKIO_WEIGHT_MAX 1000
241 #define BLKIO_WEIGHT_DEFAULT 500
243 #ifdef CONFIG_DEBUG_BLK_CGROUP
244 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
245 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
246 unsigned long dequeue);
247 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
248 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
249 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
251 #define BLKG_FLAG_FNS(name) \
252 static inline void blkio_mark_blkg_##name( \
253 struct blkio_group_stats *stats) \
255 stats->flags |= (1 << BLKG_##name); \
257 static inline void blkio_clear_blkg_##name( \
258 struct blkio_group_stats *stats) \
260 stats->flags &= ~(1 << BLKG_##name); \
262 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
264 return (stats->flags & (1 << BLKG_##name)) != 0; \
267 BLKG_FLAG_FNS(waiting)
268 BLKG_FLAG_FNS(idling)
272 static inline void blkiocg_update_avg_queue_size_stats(
273 struct blkio_group *blkg) {}
274 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
275 unsigned long dequeue) {}
276 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
278 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
279 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
282 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
283 extern struct blkio_cgroup blkio_root_cgroup;
284 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
285 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
286 struct blkio_group *blkg, void *key, dev_t dev,
287 enum blkio_policy_id plid);
288 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
289 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
291 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
293 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
294 bool direction, bool sync);
295 void blkiocg_update_completion_stats(struct blkio_group *blkg,
296 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
297 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
299 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
300 struct blkio_group *curr_blkg, bool direction, bool sync);
301 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
302 bool direction, bool sync);
305 static inline struct blkio_cgroup *
306 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
308 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
309 struct blkio_group *blkg, void *key, dev_t dev,
310 enum blkio_policy_id plid) {}
313 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
315 static inline struct blkio_group *
316 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
317 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
318 unsigned long time) {}
319 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
320 uint64_t bytes, bool direction, bool sync) {}
321 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
322 uint64_t start_time, uint64_t io_start_time, bool direction,
324 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
325 bool direction, bool sync) {}
326 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
327 struct blkio_group *curr_blkg, bool direction, bool sync) {}
328 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
329 bool direction, bool sync) {}
331 #endif /* _BLK_CGROUP_H */