blkio: Recalculate the throttled bio dispatch time upon throttle limit change
[linux-2.6-block.git] / block / blk-cgroup.h
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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
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18enum blkio_policy_id {
19 BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
4c9eefa1 20 BLKIO_POLICY_THROTL, /* Throttling */
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21};
22
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23#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
24
25#ifndef CONFIG_BLK_CGROUP
26/* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
27extern struct cgroup_subsys blkio_subsys;
28#define blkio_subsys_id blkio_subsys.subsys_id
29#endif
2f5ea477 30
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31enum stat_type {
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 */
39 BLKIO_STAT_SERVICED,
40 /* Total time spent waiting in scheduler queue in ns */
41 BLKIO_STAT_WAIT_TIME,
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42 /* Number of IOs merged */
43 BLKIO_STAT_MERGED,
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44 /* Number of IOs queued up */
45 BLKIO_STAT_QUEUED,
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46 /* All the single valued stats go below this */
47 BLKIO_STAT_TIME,
48 BLKIO_STAT_SECTORS,
49#ifdef CONFIG_DEBUG_BLK_CGROUP
cdc1184c 50 BLKIO_STAT_AVG_QUEUE_SIZE,
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51 BLKIO_STAT_IDLE_TIME,
52 BLKIO_STAT_EMPTY_TIME,
53 BLKIO_STAT_GROUP_WAIT_TIME,
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54 BLKIO_STAT_DEQUEUE
55#endif
56};
57
58enum stat_sub_type {
59 BLKIO_STAT_READ = 0,
60 BLKIO_STAT_WRITE,
61 BLKIO_STAT_SYNC,
62 BLKIO_STAT_ASYNC,
63 BLKIO_STAT_TOTAL
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64};
65
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66/* blkg state flags */
67enum blkg_state_flags {
68 BLKG_waiting = 0,
69 BLKG_idling,
70 BLKG_empty,
71};
72
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73/* cgroup files owned by proportional weight policy */
74enum 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,
79 BLKIO_PROP_time,
80 BLKIO_PROP_sectors,
81 BLKIO_PROP_io_service_time,
82 BLKIO_PROP_io_wait_time,
83 BLKIO_PROP_io_merged,
84 BLKIO_PROP_io_queued,
85 BLKIO_PROP_avg_queue_size,
86 BLKIO_PROP_group_wait_time,
87 BLKIO_PROP_idle_time,
88 BLKIO_PROP_empty_time,
89 BLKIO_PROP_dequeue,
90};
91
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92/* cgroup files owned by throttle policy */
93enum blkcg_file_name_throtl {
94 BLKIO_THROTL_read_bps_device,
95 BLKIO_THROTL_write_bps_device,
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96 BLKIO_THROTL_read_iops_device,
97 BLKIO_THROTL_write_iops_device,
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98 BLKIO_THROTL_io_service_bytes,
99 BLKIO_THROTL_io_serviced,
100};
101
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102struct blkio_cgroup {
103 struct cgroup_subsys_state css;
104 unsigned int weight;
105 spinlock_t lock;
106 struct hlist_head blkg_list;
34d0f179 107 struct list_head policy_list; /* list of blkio_policy_node */
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108};
109
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110struct blkio_group_stats {
111 /* total disk time and nr sectors dispatched by this group */
112 uint64_t time;
113 uint64_t sectors;
cdc1184c 114 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
303a3acb 115#ifdef CONFIG_DEBUG_BLK_CGROUP
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116 /* Sum of number of IOs queued across all samples */
117 uint64_t avg_queue_size_sum;
118 /* Count of samples taken for average */
119 uint64_t avg_queue_size_samples;
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120 /* How many times this group has been removed from service tree */
121 unsigned long dequeue;
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122
123 /* Total time spent waiting for it to be assigned a timeslice. */
124 uint64_t group_wait_time;
125 uint64_t start_group_wait_time;
126
127 /* Time spent idling for this blkio_group */
128 uint64_t idle_time;
129 uint64_t start_idle_time;
130 /*
131 * Total time when we have requests queued and do not contain the
132 * current active queue.
133 */
134 uint64_t empty_time;
135 uint64_t start_empty_time;
136 uint16_t flags;
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137#endif
138};
139
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140struct blkio_group {
141 /* An rcu protected unique identifier for the group */
142 void *key;
143 struct hlist_node blkcg_node;
b1c35769 144 unsigned short blkcg_id;
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145 /* Store cgroup path */
146 char path[128];
22084190 147 /* The device MKDEV(major, minor), this group has been created for */
84c124da 148 dev_t dev;
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149 /* policy which owns this blk group */
150 enum blkio_policy_id plid;
22084190 151
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152 /* Need to serialize the stats in the case of reset/update */
153 spinlock_t stats_lock;
154 struct blkio_group_stats stats;
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155};
156
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157struct blkio_policy_node {
158 struct list_head node;
159 dev_t dev;
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160 /* This node belongs to max bw policy or porportional weight policy */
161 enum blkio_policy_id plid;
162 /* cgroup file to which this rule belongs to */
163 int fileid;
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164
165 union {
166 unsigned int weight;
167 /*
168 * Rate read/write in terms of byptes per second
169 * Whether this rate represents read or write is determined
170 * by file type "fileid".
171 */
172 u64 bps;
7702e8f4 173 unsigned int iops;
4c9eefa1 174 } val;
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175};
176
177extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
178 dev_t dev);
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179extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
180 dev_t dev);
181extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
182 dev_t dev);
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183extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
184 dev_t dev);
185extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
186 dev_t dev);
34d0f179 187
3e252066 188typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
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189
190typedef void (blkio_update_group_weight_fn) (void *key,
191 struct blkio_group *blkg, unsigned int weight);
192typedef void (blkio_update_group_read_bps_fn) (void * key,
193 struct blkio_group *blkg, u64 read_bps);
194typedef void (blkio_update_group_write_bps_fn) (void *key,
195 struct blkio_group *blkg, u64 write_bps);
196typedef void (blkio_update_group_read_iops_fn) (void *key,
197 struct blkio_group *blkg, unsigned int read_iops);
198typedef void (blkio_update_group_write_iops_fn) (void *key,
199 struct blkio_group *blkg, unsigned int write_iops);
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200
201struct blkio_policy_ops {
202 blkio_unlink_group_fn *blkio_unlink_group_fn;
203 blkio_update_group_weight_fn *blkio_update_group_weight_fn;
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204 blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
205 blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
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206 blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
207 blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
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208};
209
210struct blkio_policy_type {
211 struct list_head list;
212 struct blkio_policy_ops ops;
062a644d 213 enum blkio_policy_id plid;
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214};
215
216/* Blkio controller policy registration */
217extern void blkio_policy_register(struct blkio_policy_type *);
218extern void blkio_policy_unregister(struct blkio_policy_type *);
219
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220static inline char *blkg_path(struct blkio_group *blkg)
221{
222 return blkg->path;
223}
224
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225#else
226
227struct blkio_group {
228};
229
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230struct blkio_policy_type {
231};
232
233static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
234static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
235
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236static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
237
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238#endif
239
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240#define BLKIO_WEIGHT_MIN 100
241#define BLKIO_WEIGHT_MAX 1000
242#define BLKIO_WEIGHT_DEFAULT 500
243
2868ef7b 244#ifdef CONFIG_DEBUG_BLK_CGROUP
a11cdaa7 245void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
9195291e 246void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
22084190 247 unsigned long dequeue);
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248void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
249void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
e5ff082e 250void blkiocg_set_start_empty_time(struct blkio_group *blkg);
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251
252#define BLKG_FLAG_FNS(name) \
253static inline void blkio_mark_blkg_##name( \
254 struct blkio_group_stats *stats) \
255{ \
256 stats->flags |= (1 << BLKG_##name); \
257} \
258static inline void blkio_clear_blkg_##name( \
259 struct blkio_group_stats *stats) \
260{ \
261 stats->flags &= ~(1 << BLKG_##name); \
262} \
263static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
264{ \
265 return (stats->flags & (1 << BLKG_##name)) != 0; \
266} \
267
268BLKG_FLAG_FNS(waiting)
269BLKG_FLAG_FNS(idling)
270BLKG_FLAG_FNS(empty)
271#undef BLKG_FLAG_FNS
2868ef7b 272#else
a11cdaa7 273static inline void blkiocg_update_avg_queue_size_stats(
cdc1184c 274 struct blkio_group *blkg) {}
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275static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
276 unsigned long dequeue) {}
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277static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
278{}
279static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
e5ff082e 280static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
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281#endif
282
67523c48 283#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
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284extern struct blkio_cgroup blkio_root_cgroup;
285extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
286extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
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287 struct blkio_group *blkg, void *key, dev_t dev,
288 enum blkio_policy_id plid);
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289extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
290extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
291 void *key);
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292void blkiocg_update_timeslice_used(struct blkio_group *blkg,
293 unsigned long time);
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294void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
295 bool direction, bool sync);
296void blkiocg_update_completion_stats(struct blkio_group *blkg,
297 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
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298void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
299 bool sync);
a11cdaa7 300void blkiocg_update_io_add_stats(struct blkio_group *blkg,
cdc1184c 301 struct blkio_group *curr_blkg, bool direction, bool sync);
a11cdaa7 302void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
cdc1184c 303 bool direction, bool sync);
31e4c28d 304#else
2f5ea477 305struct cgroup;
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306static inline struct blkio_cgroup *
307cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
308
309static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
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310 struct blkio_group *blkg, void *key, dev_t dev,
311 enum blkio_policy_id plid) {}
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312
313static inline int
314blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
315
316static inline struct blkio_group *
317blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
303a3acb 318static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
9a0785b0 319 unsigned long time) {}
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320static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
321 uint64_t bytes, bool direction, bool sync) {}
322static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
323 uint64_t start_time, uint64_t io_start_time, bool direction,
324 bool sync) {}
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325static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
326 bool direction, bool sync) {}
a11cdaa7 327static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
cdc1184c 328 struct blkio_group *curr_blkg, bool direction, bool sync) {}
a11cdaa7 329static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
cdc1184c 330 bool direction, bool sync) {}
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331#endif
332#endif /* _BLK_CGROUP_H */