block/blk-cgroup.h

   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
  18 enum 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 */
  30 extern struct cgroup_subsys blkio_subsys;
  31 #define blkio_subsys_id blkio_subsys.subsys_id
  32 #endif
  33
  34 enum 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         /* Time not charged to this cgroup */
  53         BLKIO_STAT_UNACCOUNTED_TIME,
  54 #ifdef CONFIG_DEBUG_BLK_CGROUP
  55         BLKIO_STAT_AVG_QUEUE_SIZE,
  56         BLKIO_STAT_IDLE_TIME,
  57         BLKIO_STAT_EMPTY_TIME,
  58         BLKIO_STAT_GROUP_WAIT_TIME,
  59         BLKIO_STAT_DEQUEUE
  60 #endif
  61 };
  62
  63 enum stat_sub_type {
  64         BLKIO_STAT_READ = 0,
  65         BLKIO_STAT_WRITE,
  66         BLKIO_STAT_SYNC,
  67         BLKIO_STAT_ASYNC,
  68         BLKIO_STAT_TOTAL
  69 };
  70
  71 /* blkg state flags */
  72 enum blkg_state_flags {
  73         BLKG_waiting = 0,
  74         BLKG_idling,
  75         BLKG_empty,
  76 };
  77
  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,
  84         BLKIO_PROP_time,
  85         BLKIO_PROP_sectors,
  86         BLKIO_PROP_unaccounted_time,
  87         BLKIO_PROP_io_service_time,
  88         BLKIO_PROP_io_wait_time,
  89         BLKIO_PROP_io_merged,
  90         BLKIO_PROP_io_queued,
  91         BLKIO_PROP_avg_queue_size,
  92         BLKIO_PROP_group_wait_time,
  93         BLKIO_PROP_idle_time,
  94         BLKIO_PROP_empty_time,
  95         BLKIO_PROP_dequeue,
  96 };
  97
  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,
 106 };
 107
 108 struct blkio_cgroup {
 109         struct cgroup_subsys_state css;
 110         unsigned int weight;
 111         spinlock_t lock;
 112         struct hlist_head blkg_list;
 113         struct list_head policy_list; /* list of blkio_policy_node */
 114 };
 115
 116 struct blkio_group_stats {
 117         /* total disk time and nr sectors dispatched by this group */
 118         uint64_t time;
 119         uint64_t sectors;
 120         /* Time not charged to this cgroup */
 121         uint64_t unaccounted_time;
 122         uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
 123 #ifdef CONFIG_DEBUG_BLK_CGROUP
 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;
 130
 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;
 134
 135         /* Time spent idling for this blkio_group */
 136         uint64_t idle_time;
 137         uint64_t start_idle_time;
 138         /*
 139          * Total time when we have requests queued and do not contain the
 140          * current active queue.
 141          */
 142         uint64_t empty_time;
 143         uint64_t start_empty_time;
 144         uint16_t flags;
 145 #endif
 146 };
 147
 148 struct blkio_group {
 149         /* An rcu protected unique identifier for the group */
 150         void *key;
 151         struct hlist_node blkcg_node;
 152         unsigned short blkcg_id;
 153         /* Store cgroup path */
 154         char path[128];
 155         /* The device MKDEV(major, minor), this group has been created for */
 156         dev_t dev;
 157         /* policy which owns this blk group */
 158         enum blkio_policy_id plid;
 159
 160         /* Need to serialize the stats in the case of reset/update */
 161         spinlock_t stats_lock;
 162         struct blkio_group_stats stats;
 163 };
 164
 165 struct blkio_policy_node {
 166         struct list_head node;
 167         dev_t dev;
 168         /* This node belongs to max bw policy or porportional weight policy */
 169         enum blkio_policy_id plid;
 170         /* cgroup file to which this rule belongs to */
 171         int fileid;
 172
 173         union {
 174                 unsigned int weight;
 175                 /*
 176                  * Rate read/write in terms of byptes per second
 177                  * Whether this rate represents read or write is determined
 178                  * by file type "fileid".
 179                  */
 180                 u64 bps;
 181                 unsigned int iops;
 182         } val;
 183 };
 184
 185 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
 186                                      dev_t dev);
 187 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
 188                                      dev_t dev);
 189 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
 190                                      dev_t dev);
 191 extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
 192                                      dev_t dev);
 193 extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
 194                                      dev_t dev);
 195
 196 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
 197
 198 typedef void (blkio_update_group_weight_fn) (void *key,
 199                         struct blkio_group *blkg, unsigned int weight);
 200 typedef void (blkio_update_group_read_bps_fn) (void * key,
 201                         struct blkio_group *blkg, u64 read_bps);
 202 typedef void (blkio_update_group_write_bps_fn) (void *key,
 203                         struct blkio_group *blkg, u64 write_bps);
 204 typedef void (blkio_update_group_read_iops_fn) (void *key,
 205                         struct blkio_group *blkg, unsigned int read_iops);
 206 typedef void (blkio_update_group_write_iops_fn) (void *key,
 207                         struct blkio_group *blkg, unsigned int write_iops);
 208
 209 struct blkio_policy_ops {
 210         blkio_unlink_group_fn *blkio_unlink_group_fn;
 211         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
 212         blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
 213         blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
 214         blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
 215         blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
 216 };
 217
 218 struct blkio_policy_type {
 219         struct list_head list;
 220         struct blkio_policy_ops ops;
 221         enum blkio_policy_id plid;
 222 };
 223
 224 /* Blkio controller policy registration */
 225 extern void blkio_policy_register(struct blkio_policy_type *);
 226 extern void blkio_policy_unregister(struct blkio_policy_type *);
 227
 228 static inline char *blkg_path(struct blkio_group *blkg)
 229 {
 230         return blkg->path;
 231 }
 232
 233 #else
 234
 235 struct blkio_group {
 236 };
 237
 238 struct blkio_policy_type {
 239 };
 240
 241 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
 242 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
 243
 244 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
 245
 246 #endif
 247
 248 #define BLKIO_WEIGHT_MIN        10
 249 #define BLKIO_WEIGHT_MAX        1000
 250 #define BLKIO_WEIGHT_DEFAULT    500
 251
 252 #ifdef CONFIG_DEBUG_BLK_CGROUP
 253 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
 254 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 255                                 unsigned long dequeue);
 256 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
 257 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
 258 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
 259
 260 #define BLKG_FLAG_FNS(name)                                             \
 261 static inline void blkio_mark_blkg_##name(                              \
 262                 struct blkio_group_stats *stats)                        \
 263 {                                                                       \
 264         stats->flags |= (1 << BLKG_##name);                             \
 265 }                                                                       \
 266 static inline void blkio_clear_blkg_##name(                             \
 267                 struct blkio_group_stats *stats)                        \
 268 {                                                                       \
 269         stats->flags &= ~(1 << BLKG_##name);                            \
 270 }                                                                       \
 271 static inline int blkio_blkg_##name(struct blkio_group_stats *stats)    \
 272 {                                                                       \
 273         return (stats->flags & (1 << BLKG_##name)) != 0;                \
 274 }                                                                       \
 275
 276 BLKG_FLAG_FNS(waiting)
 277 BLKG_FLAG_FNS(idling)
 278 BLKG_FLAG_FNS(empty)
 279 #undef BLKG_FLAG_FNS
 280 #else
 281 static inline void blkiocg_update_avg_queue_size_stats(
 282                                                 struct blkio_group *blkg) {}
 283 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 284                                                 unsigned long dequeue) {}
 285 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
 286 {}
 287 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
 288 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
 289 #endif
 290
 291 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
 292 extern struct blkio_cgroup blkio_root_cgroup;
 293 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
 294 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 295         struct blkio_group *blkg, void *key, dev_t dev,
 296         enum blkio_policy_id plid);
 297 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 298 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
 299                                                 void *key);
 300 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 301                                         unsigned long time,
 302                                         unsigned long unaccounted_time);
 303 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
 304                                                 bool direction, bool sync);
 305 void blkiocg_update_completion_stats(struct blkio_group *blkg,
 306         uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
 307 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
 308                                         bool sync);
 309 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 310                 struct blkio_group *curr_blkg, bool direction, bool sync);
 311 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 312                                         bool direction, bool sync);
 313 #else
 314 struct cgroup;
 315 static inline struct blkio_cgroup *
 316 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
 317
 318 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 319                 struct blkio_group *blkg, void *key, dev_t dev,
 320                 enum blkio_policy_id plid) {}
 321
 322 static inline int
 323 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
 324
 325 static inline struct blkio_group *
 326 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
 327 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 328                                                 unsigned long time,
 329                                                 unsigned long unaccounted_time)
 330 {}
 331 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
 332                                 uint64_t bytes, bool direction, bool sync) {}
 333 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
 334                 uint64_t start_time, uint64_t io_start_time, bool direction,
 335                 bool sync) {}
 336 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
 337                                                 bool direction, bool sync) {}
 338 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 339                 struct blkio_group *curr_blkg, bool direction, bool sync) {}
 340 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 341                                                 bool direction, bool sync) {}
 342 #endif
 343 #endif /* _BLK_CGROUP_H */