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         BLKIO_NR_POLICIES,
  24 };
  25
  26 /* Max limits for throttle policy */
  27 #define THROTL_IOPS_MAX         UINT_MAX
  28
  29 #ifdef CONFIG_BLK_CGROUP
  30
  31 enum 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 time spent waiting in scheduler queue in ns */
  37         BLKIO_STAT_WAIT_TIME,
  38         /* Number of IOs queued up */
  39         BLKIO_STAT_QUEUED,
  40         /* All the single valued stats go below this */
  41         BLKIO_STAT_TIME,
  42 #ifdef CONFIG_DEBUG_BLK_CGROUP
  43         /* Time not charged to this cgroup */
  44         BLKIO_STAT_UNACCOUNTED_TIME,
  45         BLKIO_STAT_AVG_QUEUE_SIZE,
  46         BLKIO_STAT_IDLE_TIME,
  47         BLKIO_STAT_EMPTY_TIME,
  48         BLKIO_STAT_GROUP_WAIT_TIME,
  49         BLKIO_STAT_DEQUEUE
  50 #endif
  51 };
  52
  53 /* Per cpu stats */
  54 enum stat_type_cpu {
  55         BLKIO_STAT_CPU_SECTORS,
  56         /* Total bytes transferred */
  57         BLKIO_STAT_CPU_SERVICE_BYTES,
  58         /* Total IOs serviced, post merge */
  59         BLKIO_STAT_CPU_SERVICED,
  60         /* Number of IOs merged */
  61         BLKIO_STAT_CPU_MERGED,
  62         BLKIO_STAT_CPU_NR
  63 };
  64
  65 enum stat_sub_type {
  66         BLKIO_STAT_READ = 0,
  67         BLKIO_STAT_WRITE,
  68         BLKIO_STAT_SYNC,
  69         BLKIO_STAT_ASYNC,
  70         BLKIO_STAT_TOTAL
  71 };
  72
  73 /* blkg state flags */
  74 enum blkg_state_flags {
  75         BLKG_waiting = 0,
  76         BLKG_idling,
  77         BLKG_empty,
  78 };
  79
  80 /* cgroup files owned by proportional weight policy */
  81 enum blkcg_file_name_prop {
  82         BLKIO_PROP_weight = 1,
  83         BLKIO_PROP_weight_device,
  84         BLKIO_PROP_io_service_bytes,
  85         BLKIO_PROP_io_serviced,
  86         BLKIO_PROP_time,
  87         BLKIO_PROP_sectors,
  88         BLKIO_PROP_unaccounted_time,
  89         BLKIO_PROP_io_service_time,
  90         BLKIO_PROP_io_wait_time,
  91         BLKIO_PROP_io_merged,
  92         BLKIO_PROP_io_queued,
  93         BLKIO_PROP_avg_queue_size,
  94         BLKIO_PROP_group_wait_time,
  95         BLKIO_PROP_idle_time,
  96         BLKIO_PROP_empty_time,
  97         BLKIO_PROP_dequeue,
  98 };
  99
 100 /* cgroup files owned by throttle policy */
 101 enum blkcg_file_name_throtl {
 102         BLKIO_THROTL_read_bps_device,
 103         BLKIO_THROTL_write_bps_device,
 104         BLKIO_THROTL_read_iops_device,
 105         BLKIO_THROTL_write_iops_device,
 106         BLKIO_THROTL_io_service_bytes,
 107         BLKIO_THROTL_io_serviced,
 108 };
 109
 110 struct blkio_cgroup {
 111         struct cgroup_subsys_state css;
 112         unsigned int weight;
 113         spinlock_t lock;
 114         struct hlist_head blkg_list;
 115         struct list_head policy_list; /* list of blkio_policy_node */
 116 };
 117
 118 struct blkio_group_stats {
 119         /* total disk time and nr sectors dispatched by this group */
 120         uint64_t time;
 121         uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
 122 #ifdef CONFIG_DEBUG_BLK_CGROUP
 123         /* Time not charged to this cgroup */
 124         uint64_t unaccounted_time;
 125
 126         /* Sum of number of IOs queued across all samples */
 127         uint64_t avg_queue_size_sum;
 128         /* Count of samples taken for average */
 129         uint64_t avg_queue_size_samples;
 130         /* How many times this group has been removed from service tree */
 131         unsigned long dequeue;
 132
 133         /* Total time spent waiting for it to be assigned a timeslice. */
 134         uint64_t group_wait_time;
 135         uint64_t start_group_wait_time;
 136
 137         /* Time spent idling for this blkio_group */
 138         uint64_t idle_time;
 139         uint64_t start_idle_time;
 140         /*
 141          * Total time when we have requests queued and do not contain the
 142          * current active queue.
 143          */
 144         uint64_t empty_time;
 145         uint64_t start_empty_time;
 146         uint16_t flags;
 147 #endif
 148 };
 149
 150 /* Per cpu blkio group stats */
 151 struct blkio_group_stats_cpu {
 152         uint64_t sectors;
 153         uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
 154         struct u64_stats_sync syncp;
 155 };
 156
 157 struct blkio_group {
 158         /* Pointer to the associated request_queue, RCU protected */
 159         struct request_queue __rcu *q;
 160         struct hlist_node blkcg_node;
 161         unsigned short blkcg_id;
 162         /* Store cgroup path */
 163         char path[128];
 164         /* The device MKDEV(major, minor), this group has been created for */
 165         dev_t dev;
 166         /* policy which owns this blk group */
 167         enum blkio_policy_id plid;
 168
 169         /* Need to serialize the stats in the case of reset/update */
 170         spinlock_t stats_lock;
 171         struct blkio_group_stats stats;
 172         /* Per cpu stats pointer */
 173         struct blkio_group_stats_cpu __percpu *stats_cpu;
 174 };
 175
 176 struct blkio_policy_node {
 177         struct list_head node;
 178         dev_t dev;
 179         /* This node belongs to max bw policy or porportional weight policy */
 180         enum blkio_policy_id plid;
 181         /* cgroup file to which this rule belongs to */
 182         int fileid;
 183
 184         union {
 185                 unsigned int weight;
 186                 /*
 187                  * Rate read/write in terms of bytes per second
 188                  * Whether this rate represents read or write is determined
 189                  * by file type "fileid".
 190                  */
 191                 u64 bps;
 192                 unsigned int iops;
 193         } val;
 194 };
 195
 196 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
 197                                      dev_t dev);
 198 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
 199                                      dev_t dev);
 200 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
 201                                      dev_t dev);
 202 extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
 203                                      dev_t dev);
 204 extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
 205                                      dev_t dev);
 206
 207 typedef struct blkio_group *(blkio_alloc_group_fn)(struct request_queue *q,
 208                                                    struct blkio_cgroup *blkcg);
 209 typedef void (blkio_link_group_fn)(struct request_queue *q,
 210                         struct blkio_group *blkg);
 211 typedef void (blkio_unlink_group_fn)(struct request_queue *q,
 212                         struct blkio_group *blkg);
 213 typedef bool (blkio_clear_queue_fn)(struct request_queue *q);
 214 typedef void (blkio_update_group_weight_fn)(struct request_queue *q,
 215                         struct blkio_group *blkg, unsigned int weight);
 216 typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q,
 217                         struct blkio_group *blkg, u64 read_bps);
 218 typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q,
 219                         struct blkio_group *blkg, u64 write_bps);
 220 typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q,
 221                         struct blkio_group *blkg, unsigned int read_iops);
 222 typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q,
 223                         struct blkio_group *blkg, unsigned int write_iops);
 224
 225 struct blkio_policy_ops {
 226         blkio_alloc_group_fn *blkio_alloc_group_fn;
 227         blkio_link_group_fn *blkio_link_group_fn;
 228         blkio_unlink_group_fn *blkio_unlink_group_fn;
 229         blkio_clear_queue_fn *blkio_clear_queue_fn;
 230         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
 231         blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
 232         blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
 233         blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
 234         blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
 235 };
 236
 237 struct blkio_policy_type {
 238         struct list_head list;
 239         struct blkio_policy_ops ops;
 240         enum blkio_policy_id plid;
 241 };
 242
 243 /* Blkio controller policy registration */
 244 extern void blkio_policy_register(struct blkio_policy_type *);
 245 extern void blkio_policy_unregister(struct blkio_policy_type *);
 246 extern void blkg_destroy_all(struct request_queue *q);
 247
 248 static inline char *blkg_path(struct blkio_group *blkg)
 249 {
 250         return blkg->path;
 251 }
 252
 253 #else
 254
 255 struct blkio_group {
 256 };
 257
 258 struct blkio_policy_type {
 259 };
 260
 261 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
 262 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
 263 static inline void blkg_destroy_all(struct request_queue *q) { }
 264
 265 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
 266
 267 #endif
 268
 269 #define BLKIO_WEIGHT_MIN        10
 270 #define BLKIO_WEIGHT_MAX        1000
 271 #define BLKIO_WEIGHT_DEFAULT    500
 272
 273 #ifdef CONFIG_DEBUG_BLK_CGROUP
 274 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
 275 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 276                                 unsigned long dequeue);
 277 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
 278 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
 279 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
 280
 281 #define BLKG_FLAG_FNS(name)                                             \
 282 static inline void blkio_mark_blkg_##name(                              \
 283                 struct blkio_group_stats *stats)                        \
 284 {                                                                       \
 285         stats->flags |= (1 << BLKG_##name);                             \
 286 }                                                                       \
 287 static inline void blkio_clear_blkg_##name(                             \
 288                 struct blkio_group_stats *stats)                        \
 289 {                                                                       \
 290         stats->flags &= ~(1 << BLKG_##name);                            \
 291 }                                                                       \
 292 static inline int blkio_blkg_##name(struct blkio_group_stats *stats)    \
 293 {                                                                       \
 294         return (stats->flags & (1 << BLKG_##name)) != 0;                \
 295 }                                                                       \
 296
 297 BLKG_FLAG_FNS(waiting)
 298 BLKG_FLAG_FNS(idling)
 299 BLKG_FLAG_FNS(empty)
 300 #undef BLKG_FLAG_FNS
 301 #else
 302 static inline void blkiocg_update_avg_queue_size_stats(
 303                                                 struct blkio_group *blkg) {}
 304 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 305                                                 unsigned long dequeue) {}
 306 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
 307 {}
 308 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
 309 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
 310 #endif
 311
 312 #ifdef CONFIG_BLK_CGROUP
 313 extern struct blkio_cgroup blkio_root_cgroup;
 314 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
 315 extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
 316 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 317 extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
 318                                        struct request_queue *q,
 319                                        enum blkio_policy_id plid);
 320 struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
 321                                        struct request_queue *q,
 322                                        enum blkio_policy_id plid,
 323                                        bool for_root);
 324 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 325                                         unsigned long time,
 326                                         unsigned long unaccounted_time);
 327 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
 328                                                 bool direction, bool sync);
 329 void blkiocg_update_completion_stats(struct blkio_group *blkg,
 330         uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
 331 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
 332                                         bool sync);
 333 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 334                 struct blkio_group *curr_blkg, bool direction, bool sync);
 335 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 336                                         bool direction, bool sync);
 337 #else
 338 struct cgroup;
 339 static inline struct blkio_cgroup *
 340 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
 341 static inline struct blkio_cgroup *
 342 task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
 343
 344 static inline int
 345 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
 346
 347 static inline struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
 348                                               void *key) { return NULL; }
 349 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 350                                                 unsigned long time,
 351                                                 unsigned long unaccounted_time)
 352 {}
 353 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
 354                                 uint64_t bytes, bool direction, bool sync) {}
 355 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
 356                 uint64_t start_time, uint64_t io_start_time, bool direction,
 357                 bool sync) {}
 358 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
 359                                                 bool direction, bool sync) {}
 360 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 361                 struct blkio_group *curr_blkg, bool direction, bool sync) {}
 362 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 363                                                 bool direction, bool sync) {}
 364 #endif
 365 #endif /* _BLK_CGROUP_H */