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>
17 #include <linux/u64_stats_sync.h>
19 enum blkio_policy_id {
20 BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
21 BLKIO_POLICY_THROTL, /* Throttling */
24 /* Max limits for throttle policy */
25 #define THROTL_IOPS_MAX UINT_MAX
27 #ifdef CONFIG_BLK_CGROUP
30 /* Total time spent (in ns) between request dispatch to the driver and
31 * request completion for IOs doen by this cgroup. This may not be
32 * accurate when NCQ is turned on. */
33 BLKIO_STAT_SERVICE_TIME = 0,
34 /* Total time spent waiting in scheduler queue in ns */
36 /* Number of IOs queued up */
38 /* All the single valued stats go below this */
40 #ifdef CONFIG_DEBUG_BLK_CGROUP
41 /* Time not charged to this cgroup */
42 BLKIO_STAT_UNACCOUNTED_TIME,
43 BLKIO_STAT_AVG_QUEUE_SIZE,
45 BLKIO_STAT_EMPTY_TIME,
46 BLKIO_STAT_GROUP_WAIT_TIME,
53 BLKIO_STAT_CPU_SECTORS,
54 /* Total bytes transferred */
55 BLKIO_STAT_CPU_SERVICE_BYTES,
56 /* Total IOs serviced, post merge */
57 BLKIO_STAT_CPU_SERVICED,
58 /* Number of IOs merged */
59 BLKIO_STAT_CPU_MERGED,
71 /* blkg state flags */
72 enum blkg_state_flags {
78 /* cgroup files owned by proportional weight policy */
79 enum blkcg_file_name_prop {
80 BLKIO_PROP_weight = 1,
81 BLKIO_PROP_weight_device,
82 BLKIO_PROP_io_service_bytes,
83 BLKIO_PROP_io_serviced,
86 BLKIO_PROP_unaccounted_time,
87 BLKIO_PROP_io_service_time,
88 BLKIO_PROP_io_wait_time,
91 BLKIO_PROP_avg_queue_size,
92 BLKIO_PROP_group_wait_time,
94 BLKIO_PROP_empty_time,
98 /* cgroup files owned by throttle policy */
99 enum blkcg_file_name_throtl {
100 BLKIO_THROTL_read_bps_device,
101 BLKIO_THROTL_write_bps_device,
102 BLKIO_THROTL_read_iops_device,
103 BLKIO_THROTL_write_iops_device,
104 BLKIO_THROTL_io_service_bytes,
105 BLKIO_THROTL_io_serviced,
108 struct blkio_cgroup {
109 struct cgroup_subsys_state css;
112 struct hlist_head blkg_list;
113 struct list_head policy_list; /* list of blkio_policy_node */
116 struct blkio_group_stats {
117 /* total disk time and nr sectors dispatched by this group */
119 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
120 #ifdef CONFIG_DEBUG_BLK_CGROUP
121 /* Time not charged to this cgroup */
122 uint64_t unaccounted_time;
124 /* Sum of number of IOs queued across all samples */
125 uint64_t avg_queue_size_sum;
126 /* Count of samples taken for average */
127 uint64_t avg_queue_size_samples;
128 /* How many times this group has been removed from service tree */
129 unsigned long dequeue;
131 /* Total time spent waiting for it to be assigned a timeslice. */
132 uint64_t group_wait_time;
133 uint64_t start_group_wait_time;
135 /* Time spent idling for this blkio_group */
137 uint64_t start_idle_time;
139 * Total time when we have requests queued and do not contain the
140 * current active queue.
143 uint64_t start_empty_time;
148 /* Per cpu blkio group stats */
149 struct blkio_group_stats_cpu {
151 uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
152 struct u64_stats_sync syncp;
156 /* An rcu protected unique identifier for the group */
158 struct hlist_node blkcg_node;
159 unsigned short blkcg_id;
160 /* Store cgroup path */
162 /* The device MKDEV(major, minor), this group has been created for */
164 /* policy which owns this blk group */
165 enum blkio_policy_id plid;
167 /* Need to serialize the stats in the case of reset/update */
168 spinlock_t stats_lock;
169 struct blkio_group_stats stats;
170 /* Per cpu stats pointer */
171 struct blkio_group_stats_cpu __percpu *stats_cpu;
174 struct blkio_policy_node {
175 struct list_head node;
177 /* This node belongs to max bw policy or porportional weight policy */
178 enum blkio_policy_id plid;
179 /* cgroup file to which this rule belongs to */
185 * Rate read/write in terms of bytes per second
186 * Whether this rate represents read or write is determined
187 * by file type "fileid".
194 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
196 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
198 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
200 extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
202 extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
205 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
206 typedef bool (blkio_clear_queue_fn)(struct request_queue *q);
207 typedef void (blkio_update_group_weight_fn) (void *key,
208 struct blkio_group *blkg, unsigned int weight);
209 typedef void (blkio_update_group_read_bps_fn) (void * key,
210 struct blkio_group *blkg, u64 read_bps);
211 typedef void (blkio_update_group_write_bps_fn) (void *key,
212 struct blkio_group *blkg, u64 write_bps);
213 typedef void (blkio_update_group_read_iops_fn) (void *key,
214 struct blkio_group *blkg, unsigned int read_iops);
215 typedef void (blkio_update_group_write_iops_fn) (void *key,
216 struct blkio_group *blkg, unsigned int write_iops);
218 struct blkio_policy_ops {
219 blkio_unlink_group_fn *blkio_unlink_group_fn;
220 blkio_clear_queue_fn *blkio_clear_queue_fn;
221 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
222 blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
223 blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
224 blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
225 blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
228 struct blkio_policy_type {
229 struct list_head list;
230 struct blkio_policy_ops ops;
231 enum blkio_policy_id plid;
234 /* Blkio controller policy registration */
235 extern void blkio_policy_register(struct blkio_policy_type *);
236 extern void blkio_policy_unregister(struct blkio_policy_type *);
237 extern void blkg_destroy_all(struct request_queue *q);
239 static inline char *blkg_path(struct blkio_group *blkg)
249 struct blkio_policy_type {
252 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
253 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
254 static inline void blkg_destroy_all(struct request_queue *q) { }
256 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
260 #define BLKIO_WEIGHT_MIN 10
261 #define BLKIO_WEIGHT_MAX 1000
262 #define BLKIO_WEIGHT_DEFAULT 500
264 #ifdef CONFIG_DEBUG_BLK_CGROUP
265 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
266 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
267 unsigned long dequeue);
268 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
269 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
270 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
272 #define BLKG_FLAG_FNS(name) \
273 static inline void blkio_mark_blkg_##name( \
274 struct blkio_group_stats *stats) \
276 stats->flags |= (1 << BLKG_##name); \
278 static inline void blkio_clear_blkg_##name( \
279 struct blkio_group_stats *stats) \
281 stats->flags &= ~(1 << BLKG_##name); \
283 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
285 return (stats->flags & (1 << BLKG_##name)) != 0; \
288 BLKG_FLAG_FNS(waiting)
289 BLKG_FLAG_FNS(idling)
293 static inline void blkiocg_update_avg_queue_size_stats(
294 struct blkio_group *blkg) {}
295 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
296 unsigned long dequeue) {}
297 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
299 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
300 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
303 #ifdef CONFIG_BLK_CGROUP
304 extern struct blkio_cgroup blkio_root_cgroup;
305 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
306 extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
307 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
308 struct blkio_group *blkg, void *key, dev_t dev,
309 enum blkio_policy_id plid);
310 extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
311 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
312 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
314 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
316 unsigned long unaccounted_time);
317 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
318 bool direction, bool sync);
319 void blkiocg_update_completion_stats(struct blkio_group *blkg,
320 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
321 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
323 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
324 struct blkio_group *curr_blkg, bool direction, bool sync);
325 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
326 bool direction, bool sync);
329 static inline struct blkio_cgroup *
330 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
331 static inline struct blkio_cgroup *
332 task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
334 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
335 struct blkio_group *blkg, void *key, dev_t dev,
336 enum blkio_policy_id plid) {}
338 static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
341 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
343 static inline struct blkio_group *
344 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
345 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
347 unsigned long unaccounted_time)
349 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
350 uint64_t bytes, bool direction, bool sync) {}
351 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
352 uint64_t start_time, uint64_t io_start_time, bool direction,
354 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
355 bool direction, bool sync) {}
356 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
357 struct blkio_group *curr_blkg, bool direction, bool sync) {}
358 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
359 bool direction, bool sync) {}
361 #endif /* _BLK_CGROUP_H */