1 #ifndef _BLK_CGROUP_H
2 #define _BLK_CGROUP_H
3 /*
4 * Common Block IO controller cgroup interface
5 *
6 * Based on ideas and code from CFQ, CFS and BFQ:
7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
8 *
9 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
10 * Paolo Valente <paolo.valente@unimore.it>
11 *
12 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
13 * Nauman Rafique <nauman@google.com>
14 */
15
16 #include <linux/cgroup.h>
17 #include <linux/u64_stats_sync.h>
18
19 enum blkio_policy_id {
20 BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
21 BLKIO_POLICY_THROTL, /* Throttling */
22 };
23
24 /* Max limits for throttle policy */
25 #define THROTL_IOPS_MAX UINT_MAX
26
27 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
28
29 #ifndef CONFIG_BLK_CGROUP
30 /* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
31 extern struct cgroup_subsys blkio_subsys;
32 #define blkio_subsys_id blkio_subsys.subsys_id
33 #endif
34
35 enum stat_type {
36 /* Total time spent (in ns) between request dispatch to the driver and
37 * request completion for IOs doen by this cgroup. This may not be
38 * accurate when NCQ is turned on. */
39 BLKIO_STAT_SERVICE_TIME = 0,
40 /* Total time spent waiting in scheduler queue in ns */
41 BLKIO_STAT_WAIT_TIME,
42 /* Number of IOs queued up */
43 BLKIO_STAT_QUEUED,
44 /* All the single valued stats go below this */
45 BLKIO_STAT_TIME,
46 #ifdef CONFIG_DEBUG_BLK_CGROUP
47 /* Time not charged to this cgroup */
48 BLKIO_STAT_UNACCOUNTED_TIME,
49 BLKIO_STAT_AVG_QUEUE_SIZE,
50 BLKIO_STAT_IDLE_TIME,
51 BLKIO_STAT_EMPTY_TIME,
52 BLKIO_STAT_GROUP_WAIT_TIME,
53 BLKIO_STAT_DEQUEUE
54 #endif
55 };
56
57 /* Per cpu stats */
58 enum stat_type_cpu {
59 BLKIO_STAT_CPU_SECTORS,
60 /* Total bytes transferred */
61 BLKIO_STAT_CPU_SERVICE_BYTES,
62 /* Total IOs serviced, post merge */
63 BLKIO_STAT_CPU_SERVICED,
64 /* Number of IOs merged */
65 BLKIO_STAT_CPU_MERGED,
66 BLKIO_STAT_CPU_NR
67 };
68
69 enum stat_sub_type {
70 BLKIO_STAT_READ = 0,
71 BLKIO_STAT_WRITE,
72 BLKIO_STAT_SYNC,
73 BLKIO_STAT_ASYNC,
74 BLKIO_STAT_TOTAL
75 };
76
77 /* blkg state flags */
78 enum blkg_state_flags {
79 BLKG_waiting = 0,
80 BLKG_idling,
81 BLKG_empty,
82 };
83
84 /* cgroup files owned by proportional weight policy */
85 enum blkcg_file_name_prop {
86 BLKIO_PROP_weight = 1,
87 BLKIO_PROP_weight_device,
88 BLKIO_PROP_io_service_bytes,
89 BLKIO_PROP_io_serviced,
90 BLKIO_PROP_time,
91 BLKIO_PROP_sectors,
92 BLKIO_PROP_unaccounted_time,
93 BLKIO_PROP_io_service_time,
94 BLKIO_PROP_io_wait_time,
95 BLKIO_PROP_io_merged,
96 BLKIO_PROP_io_queued,
97 BLKIO_PROP_avg_queue_size,
98 BLKIO_PROP_group_wait_time,
99 BLKIO_PROP_idle_time,
100 BLKIO_PROP_empty_time,
101 BLKIO_PROP_dequeue,
102 };
103
104 /* cgroup files owned by throttle policy */
105 enum blkcg_file_name_throtl {
106 BLKIO_THROTL_read_bps_device,
107 BLKIO_THROTL_write_bps_device,
108 BLKIO_THROTL_read_iops_device,
109 BLKIO_THROTL_write_iops_device,
110 BLKIO_THROTL_io_service_bytes,
111 BLKIO_THROTL_io_serviced,
112 };
113
114 struct blkio_cgroup {
115 struct cgroup_subsys_state css;
116 unsigned int weight;
117 spinlock_t lock;
118 struct hlist_head blkg_list;
119 struct list_head policy_list; /* list of blkio_policy_node */
120 };
121
122 struct blkio_group_stats {
123 /* total disk time and nr sectors dispatched by this group */
124 uint64_t time;
125 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
126 #ifdef CONFIG_DEBUG_BLK_CGROUP
127 /* Time not charged to this cgroup */
128 uint64_t unaccounted_time;
129
130 /* Sum of number of IOs queued across all samples */
131 uint64_t avg_queue_size_sum;
132 /* Count of samples taken for average */
133 uint64_t avg_queue_size_samples;
134 /* How many times this group has been removed from service tree */
135 unsigned long dequeue;
136
137 /* Total time spent waiting for it to be assigned a timeslice. */
138 uint64_t group_wait_time;
139 uint64_t start_group_wait_time;
140
141 /* Time spent idling for this blkio_group */
142 uint64_t idle_time;
143 uint64_t start_idle_time;
144 /*
145 * Total time when we have requests queued and do not contain the
146 * current active queue.
147 */
148 uint64_t empty_time;
149 uint64_t start_empty_time;
150 uint16_t flags;
151 #endif
152 };
153
154 /* Per cpu blkio group stats */
155 struct blkio_group_stats_cpu {
156 uint64_t sectors;
157 uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
158 struct u64_stats_sync syncp;
159 };
160
161 struct blkio_group {
162 /* An rcu protected unique identifier for the group */
163 void *key;
164 struct hlist_node blkcg_node;
165 unsigned short blkcg_id;
166 /* Store cgroup path */
167 char path[128];
168 /* The device MKDEV(major, minor), this group has been created for */
169 dev_t dev;
170 /* policy which owns this blk group */
171 enum blkio_policy_id plid;
172
173 /* Need to serialize the stats in the case of reset/update */
174 spinlock_t stats_lock;
175 struct blkio_group_stats stats;
176 /* Per cpu stats pointer */
177 struct blkio_group_stats_cpu __percpu *stats_cpu;
178 };
179
180 struct blkio_policy_node {
181 struct list_head node;
182 dev_t dev;
183 /* This node belongs to max bw policy or porportional weight policy */
184 enum blkio_policy_id plid;
185 /* cgroup file to which this rule belongs to */
186 int fileid;
187
188 union {
189 unsigned int weight;
190 /*
191 * Rate read/write in terms of bytes per second
192 * Whether this rate represents read or write is determined
193 * by file type "fileid".
194 */
195 u64 bps;
196 unsigned int iops;
197 } val;
198 };
199
200 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
201 dev_t dev);
202 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
203 dev_t dev);
204 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
205 dev_t dev);
206 extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
207 dev_t dev);
208 extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
209 dev_t dev);
210
211 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
212
213 typedef void (blkio_update_group_weight_fn) (void *key,
214 struct blkio_group *blkg, unsigned int weight);
215 typedef void (blkio_update_group_read_bps_fn) (void * key,
216 struct blkio_group *blkg, u64 read_bps);
217 typedef void (blkio_update_group_write_bps_fn) (void *key,
218 struct blkio_group *blkg, u64 write_bps);
219 typedef void (blkio_update_group_read_iops_fn) (void *key,
220 struct blkio_group *blkg, unsigned int read_iops);
221 typedef void (blkio_update_group_write_iops_fn) (void *key,
222 struct blkio_group *blkg, unsigned int write_iops);
223
224 struct blkio_policy_ops {
225 blkio_unlink_group_fn *blkio_unlink_group_fn;
226 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
227 blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
228 blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
229 blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
230 blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
231 };
232
233 struct blkio_policy_type {
234 struct list_head list;
235 struct blkio_policy_ops ops;
236 enum blkio_policy_id plid;
237 };
238
239 /* Blkio controller policy registration */
240 extern void blkio_policy_register(struct blkio_policy_type *);
241 extern void blkio_policy_unregister(struct blkio_policy_type *);
242
blkg_path(struct blkio_group * blkg)243 static inline char *blkg_path(struct blkio_group *blkg)
244 {
245 return blkg->path;
246 }
247
248 #else
249
250 struct blkio_group {
251 };
252
253 struct blkio_policy_type {
254 };
255
blkio_policy_register(struct blkio_policy_type * blkiop)256 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
blkio_policy_unregister(struct blkio_policy_type * blkiop)257 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
258
blkg_path(struct blkio_group * blkg)259 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
260
261 #endif
262
263 #define BLKIO_WEIGHT_MIN 10
264 #define BLKIO_WEIGHT_MAX 1000
265 #define BLKIO_WEIGHT_DEFAULT 500
266
267 #ifdef CONFIG_DEBUG_BLK_CGROUP
268 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
269 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
270 unsigned long dequeue);
271 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
272 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
273 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
274
275 #define BLKG_FLAG_FNS(name) \
276 static inline void blkio_mark_blkg_##name( \
277 struct blkio_group_stats *stats) \
278 { \
279 stats->flags |= (1 << BLKG_##name); \
280 } \
281 static inline void blkio_clear_blkg_##name( \
282 struct blkio_group_stats *stats) \
283 { \
284 stats->flags &= ~(1 << BLKG_##name); \
285 } \
286 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
287 { \
288 return (stats->flags & (1 << BLKG_##name)) != 0; \
289 } \
290
291 BLKG_FLAG_FNS(waiting)
292 BLKG_FLAG_FNS(idling)
293 BLKG_FLAG_FNS(empty)
294 #undef BLKG_FLAG_FNS
295 #else
296 static inline void blkiocg_update_avg_queue_size_stats(
297 struct blkio_group *blkg) {}
298 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
299 unsigned long dequeue) {}
300 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
301 {}
302 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
303 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
304 #endif
305
306 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
307 extern struct blkio_cgroup blkio_root_cgroup;
308 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
309 extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
310 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
311 struct blkio_group *blkg, void *key, dev_t dev,
312 enum blkio_policy_id plid);
313 extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
314 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
315 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
316 void *key);
317 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
318 unsigned long time,
319 unsigned long unaccounted_time);
320 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
321 bool direction, bool sync);
322 void blkiocg_update_completion_stats(struct blkio_group *blkg,
323 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
324 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
325 bool sync);
326 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
327 struct blkio_group *curr_blkg, bool direction, bool sync);
328 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
329 bool direction, bool sync);
330 #else
331 struct cgroup;
332 static inline struct blkio_cgroup *
333 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
334 static inline struct blkio_cgroup *
335 task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
336
337 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
338 struct blkio_group *blkg, void *key, dev_t dev,
339 enum blkio_policy_id plid) {}
340
341 static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
342
343 static inline int
344 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
345
346 static inline struct blkio_group *
347 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
348 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
349 unsigned long time,
350 unsigned long unaccounted_time)
351 {}
352 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
353 uint64_t bytes, bool direction, bool sync) {}
354 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
355 uint64_t start_time, uint64_t io_start_time, bool direction,
356 bool sync) {}
357 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
358 bool direction, bool sync) {}
359 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
360 struct blkio_group *curr_blkg, bool direction, bool sync) {}
361 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
362 bool direction, bool sync) {}
363 #endif
364 #endif /* _BLK_CGROUP_H */
365