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