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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
19enum 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 */
31extern struct cgroup_subsys blkio_subsys;
32#define blkio_subsys_id blkio_subsys.subsys_id
33#endif
34
35enum 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 */
58enum 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
69enum 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 */
78enum blkg_state_flags {
79 BLKG_waiting = 0,
80 BLKG_idling,
81 BLKG_empty,
82};
83
84/* cgroup files owned by proportional weight policy */
85enum 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 */
105enum 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
114struct 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
122struct 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 */
155struct 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
161struct 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
180struct 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 byptes 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
200extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
201 dev_t dev);
202extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
203 dev_t dev);
204extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
205 dev_t dev);
206extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
207 dev_t dev);
208extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
209 dev_t dev);
210
211typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
212
213typedef void (blkio_update_group_weight_fn) (void *key,
214 struct blkio_group *blkg, unsigned int weight);
215typedef void (blkio_update_group_read_bps_fn) (void * key,
216 struct blkio_group *blkg, u64 read_bps);
217typedef void (blkio_update_group_write_bps_fn) (void *key,
218 struct blkio_group *blkg, u64 write_bps);
219typedef void (blkio_update_group_read_iops_fn) (void *key,
220 struct blkio_group *blkg, unsigned int read_iops);
221typedef void (blkio_update_group_write_iops_fn) (void *key,
222 struct blkio_group *blkg, unsigned int write_iops);
223
224struct 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
233struct 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 */
240extern void blkio_policy_register(struct blkio_policy_type *);
241extern void blkio_policy_unregister(struct blkio_policy_type *);
242
243static inline char *blkg_path(struct blkio_group *blkg)
244{
245 return blkg->path;
246}
247
248#else
249
250struct blkio_group {
251};
252
253struct blkio_policy_type {
254};
255
256static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
257static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
258
259static 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
268void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
269void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
270 unsigned long dequeue);
271void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
272void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
273void blkiocg_set_start_empty_time(struct blkio_group *blkg);
274
275#define BLKG_FLAG_FNS(name) \
276static inline void blkio_mark_blkg_##name( \
277 struct blkio_group_stats *stats) \
278{ \
279 stats->flags |= (1 << BLKG_##name); \
280} \
281static inline void blkio_clear_blkg_##name( \
282 struct blkio_group_stats *stats) \
283{ \
284 stats->flags &= ~(1 << BLKG_##name); \
285} \
286static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
287{ \
288 return (stats->flags & (1 << BLKG_##name)) != 0; \
289} \
290
291BLKG_FLAG_FNS(waiting)
292BLKG_FLAG_FNS(idling)
293BLKG_FLAG_FNS(empty)
294#undef BLKG_FLAG_FNS
295#else
296static inline void blkiocg_update_avg_queue_size_stats(
297 struct blkio_group *blkg) {}
298static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
299 unsigned long dequeue) {}
300static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
301{}
302static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
303static 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)
307extern struct blkio_cgroup blkio_root_cgroup;
308extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
309extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
310extern 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);
313extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
314extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
315extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
316 void *key);
317void blkiocg_update_timeslice_used(struct blkio_group *blkg,
318 unsigned long time,
319 unsigned long unaccounted_time);
320void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
321 bool direction, bool sync);
322void blkiocg_update_completion_stats(struct blkio_group *blkg,
323 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
324void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
325 bool sync);
326void blkiocg_update_io_add_stats(struct blkio_group *blkg,
327 struct blkio_group *curr_blkg, bool direction, bool sync);
328void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
329 bool direction, bool sync);
330#else
331struct cgroup;
332static inline struct blkio_cgroup *
333cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
334static inline struct blkio_cgroup *
335task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
336
337static 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
341static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
342
343static inline int
344blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
345
346static inline struct blkio_group *
347blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
348static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
349 unsigned long time,
350 unsigned long unaccounted_time)
351{}
352static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
353 uint64_t bytes, bool direction, bool sync) {}
354static 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) {}
357static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
358 bool direction, bool sync) {}
359static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
360 struct blkio_group *curr_blkg, bool direction, bool sync) {}
361static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
362 bool direction, bool sync) {}
363#endif
364#endif /* _BLK_CGROUP_H */