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_io_service_bytes,
97 BLKIO_THROTL_io_serviced,
100 struct blkio_cgroup {
101 struct cgroup_subsys_state css;
104 struct hlist_head blkg_list;
105 struct list_head policy_list; /* list of blkio_policy_node */
108 struct blkio_group_stats {
109 /* total disk time and nr sectors dispatched by this group */
112 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
113 #ifdef CONFIG_DEBUG_BLK_CGROUP
114 /* Sum of number of IOs queued across all samples */
115 uint64_t avg_queue_size_sum;
116 /* Count of samples taken for average */
117 uint64_t avg_queue_size_samples;
118 /* How many times this group has been removed from service tree */
119 unsigned long dequeue;
121 /* Total time spent waiting for it to be assigned a timeslice. */
122 uint64_t group_wait_time;
123 uint64_t start_group_wait_time;
125 /* Time spent idling for this blkio_group */
127 uint64_t start_idle_time;
129 * Total time when we have requests queued and do not contain the
130 * current active queue.
133 uint64_t start_empty_time;
139 /* An rcu protected unique identifier for the group */
141 struct hlist_node blkcg_node;
142 unsigned short blkcg_id;
143 /* Store cgroup path */
145 /* The device MKDEV(major, minor), this group has been created for */
147 /* policy which owns this blk group */
148 enum blkio_policy_id plid;
150 /* Need to serialize the stats in the case of reset/update */
151 spinlock_t stats_lock;
152 struct blkio_group_stats stats;
155 struct blkio_policy_node {
156 struct list_head node;
158 /* This node belongs to max bw policy or porportional weight policy */
159 enum blkio_policy_id plid;
160 /* cgroup file to which this rule belongs to */
166 * Rate read/write in terms of byptes per second
167 * Whether this rate represents read or write is determined
168 * by file type "fileid".
174 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
176 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
178 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
181 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
182 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
183 unsigned int weight);
184 typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
186 typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
189 struct blkio_policy_ops {
190 blkio_unlink_group_fn *blkio_unlink_group_fn;
191 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
192 blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
193 blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
196 struct blkio_policy_type {
197 struct list_head list;
198 struct blkio_policy_ops ops;
199 enum blkio_policy_id plid;
202 /* Blkio controller policy registration */
203 extern void blkio_policy_register(struct blkio_policy_type *);
204 extern void blkio_policy_unregister(struct blkio_policy_type *);
206 static inline char *blkg_path(struct blkio_group *blkg)
216 struct blkio_policy_type {
219 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
220 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
222 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
226 #define BLKIO_WEIGHT_MIN 100
227 #define BLKIO_WEIGHT_MAX 1000
228 #define BLKIO_WEIGHT_DEFAULT 500
230 #ifdef CONFIG_DEBUG_BLK_CGROUP
231 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
232 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
233 unsigned long dequeue);
234 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
235 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
236 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
238 #define BLKG_FLAG_FNS(name) \
239 static inline void blkio_mark_blkg_##name( \
240 struct blkio_group_stats *stats) \
242 stats->flags |= (1 << BLKG_##name); \
244 static inline void blkio_clear_blkg_##name( \
245 struct blkio_group_stats *stats) \
247 stats->flags &= ~(1 << BLKG_##name); \
249 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
251 return (stats->flags & (1 << BLKG_##name)) != 0; \
254 BLKG_FLAG_FNS(waiting)
255 BLKG_FLAG_FNS(idling)
259 static inline void blkiocg_update_avg_queue_size_stats(
260 struct blkio_group *blkg) {}
261 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
262 unsigned long dequeue) {}
263 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
265 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
266 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
269 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
270 extern struct blkio_cgroup blkio_root_cgroup;
271 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
272 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
273 struct blkio_group *blkg, void *key, dev_t dev,
274 enum blkio_policy_id plid);
275 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
276 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
278 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
280 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
281 bool direction, bool sync);
282 void blkiocg_update_completion_stats(struct blkio_group *blkg,
283 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
284 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
286 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
287 struct blkio_group *curr_blkg, bool direction, bool sync);
288 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
289 bool direction, bool sync);
292 static inline struct blkio_cgroup *
293 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
295 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
296 struct blkio_group *blkg, void *key, dev_t dev,
297 enum blkio_policy_id plid) {}
300 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
302 static inline struct blkio_group *
303 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
304 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
305 unsigned long time) {}
306 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
307 uint64_t bytes, bool direction, bool sync) {}
308 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
309 uint64_t start_time, uint64_t io_start_time, bool direction,
311 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
312 bool direction, bool sync) {}
313 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
314 struct blkio_group *curr_blkg, bool direction, bool sync) {}
315 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
316 bool direction, bool sync) {}
318 #endif /* _BLK_CGROUP_H */