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 #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 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
 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
 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
 256 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
 257 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
 258
 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 */