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 #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 */
  27 extern struct cgroup_subsys blkio_subsys;
  28 #define blkio_subsys_id blkio_subsys.subsys_id
  29 #endif
  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 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,
  42         /* Number of IOs merged */
  43         BLKIO_STAT_MERGED,
  44         /* Number of IOs queued up */
  45         BLKIO_STAT_QUEUED,
  46         /* All the single valued stats go below this */
  47         BLKIO_STAT_TIME,
  48         BLKIO_STAT_SECTORS,
  49 #ifdef CONFIG_DEBUG_BLK_CGROUP
  50         BLKIO_STAT_AVG_QUEUE_SIZE,
  51         BLKIO_STAT_IDLE_TIME,
  52         BLKIO_STAT_EMPTY_TIME,
  53         BLKIO_STAT_GROUP_WAIT_TIME,
  54         BLKIO_STAT_DEQUEUE
  55 #endif
  56 };
  57
  58 enum stat_sub_type {
  59         BLKIO_STAT_READ = 0,
  60         BLKIO_STAT_WRITE,
  61         BLKIO_STAT_SYNC,
  62         BLKIO_STAT_ASYNC,
  63         BLKIO_STAT_TOTAL
  64 };
  65
  66 /* blkg state flags */
  67 enum blkg_state_flags {
  68         BLKG_waiting = 0,
  69         BLKG_idling,
  70         BLKG_empty,
  71 };
  72
  73 /* cgroup files owned by proportional weight policy */
  74 enum 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
  92 /* cgroup files owned by throttle policy */
  93 enum blkcg_file_name_throtl {
  94         BLKIO_THROTL_read_bps_device,
  95         BLKIO_THROTL_write_bps_device,
  96         BLKIO_THROTL_read_iops_device,
  97         BLKIO_THROTL_write_iops_device,
  98         BLKIO_THROTL_io_service_bytes,
  99         BLKIO_THROTL_io_serviced,
 100 };
 101
 102 struct blkio_cgroup {
 103         struct cgroup_subsys_state css;
 104         unsigned int weight;
 105         spinlock_t lock;
 106         struct hlist_head blkg_list;
 107         struct list_head policy_list; /* list of blkio_policy_node */
 108 };
 109
 110 struct blkio_group_stats {
 111         /* total disk time and nr sectors dispatched by this group */
 112         uint64_t time;
 113         uint64_t sectors;
 114         uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
 115 #ifdef CONFIG_DEBUG_BLK_CGROUP
 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;
 120         /* How many times this group has been removed from service tree */
 121         unsigned long dequeue;
 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;
 137 #endif
 138 };
 139
 140 struct blkio_group {
 141         /* An rcu protected unique identifier for the group */
 142         void *key;
 143         struct hlist_node blkcg_node;
 144         unsigned short blkcg_id;
 145         /* Store cgroup path */
 146         char path[128];
 147         /* The device MKDEV(major, minor), this group has been created for */
 148         dev_t dev;
 149         /* policy which owns this blk group */
 150         enum blkio_policy_id plid;
 151
 152         /* Need to serialize the stats in the case of reset/update */
 153         spinlock_t stats_lock;
 154         struct blkio_group_stats stats;
 155 };
 156
 157 struct blkio_policy_node {
 158         struct list_head node;
 159         dev_t dev;
 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;
 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;
 173                 unsigned int iops;
 174         } val;
 175 };
 176
 177 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
 178                                      dev_t dev);
 179 extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
 180                                      dev_t dev);
 181 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
 182                                      dev_t dev);
 183 extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
 184                                      dev_t dev);
 185 extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
 186                                      dev_t dev);
 187
 188 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
 189
 190 typedef void (blkio_update_group_weight_fn) (void *key,
 191                         struct blkio_group *blkg, unsigned int weight);
 192 typedef void (blkio_update_group_read_bps_fn) (void * key,
 193                         struct blkio_group *blkg, u64 read_bps);
 194 typedef void (blkio_update_group_write_bps_fn) (void *key,
 195                         struct blkio_group *blkg, u64 write_bps);
 196 typedef void (blkio_update_group_read_iops_fn) (void *key,
 197                         struct blkio_group *blkg, unsigned int read_iops);
 198 typedef void (blkio_update_group_write_iops_fn) (void *key,
 199                         struct blkio_group *blkg, unsigned int write_iops);
 200
 201 struct blkio_policy_ops {
 202         blkio_unlink_group_fn *blkio_unlink_group_fn;
 203         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
 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;
 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;
 208 };
 209
 210 struct blkio_policy_type {
 211         struct list_head list;
 212         struct blkio_policy_ops ops;
 213         enum blkio_policy_id plid;
 214 };
 215
 216 /* Blkio controller policy registration */
 217 extern void blkio_policy_register(struct blkio_policy_type *);
 218 extern void blkio_policy_unregister(struct blkio_policy_type *);
 219
 220 static inline char *blkg_path(struct blkio_group *blkg)
 221 {
 222         return blkg->path;
 223 }
 224
 225 #else
 226
 227 struct blkio_group {
 228 };
 229
 230 struct blkio_policy_type {
 231 };
 232
 233 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
 234 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
 235
 236 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
 237
 238 #endif
 239
 240 #define BLKIO_WEIGHT_MIN        100
 241 #define BLKIO_WEIGHT_MAX        1000
 242 #define BLKIO_WEIGHT_DEFAULT    500
 243
 244 #ifdef CONFIG_DEBUG_BLK_CGROUP
 245 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
 246 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 247                                 unsigned long dequeue);
 248 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
 249 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
 250 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
 251
 252 #define BLKG_FLAG_FNS(name)                                             \
 253 static inline void blkio_mark_blkg_##name(                              \
 254                 struct blkio_group_stats *stats)                        \
 255 {                                                                       \
 256         stats->flags |= (1 << BLKG_##name);                             \
 257 }                                                                       \
 258 static inline void blkio_clear_blkg_##name(                             \
 259                 struct blkio_group_stats *stats)                        \
 260 {                                                                       \
 261         stats->flags &= ~(1 << BLKG_##name);                            \
 262 }                                                                       \
 263 static inline int blkio_blkg_##name(struct blkio_group_stats *stats)    \
 264 {                                                                       \
 265         return (stats->flags & (1 << BLKG_##name)) != 0;                \
 266 }                                                                       \
 267
 268 BLKG_FLAG_FNS(waiting)
 269 BLKG_FLAG_FNS(idling)
 270 BLKG_FLAG_FNS(empty)
 271 #undef BLKG_FLAG_FNS
 272 #else
 273 static inline void blkiocg_update_avg_queue_size_stats(
 274                                                 struct blkio_group *blkg) {}
 275 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 276                                                 unsigned long dequeue) {}
 277 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
 278 {}
 279 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
 280 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
 281 #endif
 282
 283 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
 284 extern struct blkio_cgroup blkio_root_cgroup;
 285 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
 286 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 287         struct blkio_group *blkg, void *key, dev_t dev,
 288         enum blkio_policy_id plid);
 289 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 290 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
 291                                                 void *key);
 292 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 293                                         unsigned long time);
 294 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
 295                                                 bool direction, bool sync);
 296 void blkiocg_update_completion_stats(struct blkio_group *blkg,
 297         uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
 298 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
 299                                         bool sync);
 300 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 301                 struct blkio_group *curr_blkg, bool direction, bool sync);
 302 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 303                                         bool direction, bool sync);
 304 #else
 305 struct cgroup;
 306 static inline struct blkio_cgroup *
 307 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
 308
 309 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 310                 struct blkio_group *blkg, void *key, dev_t dev,
 311                 enum blkio_policy_id plid) {}
 312
 313 static inline int
 314 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
 315
 316 static inline struct blkio_group *
 317 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
 318 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 319                                                 unsigned long time) {}
 320 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
 321                                 uint64_t bytes, bool direction, bool sync) {}
 322 static 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) {}
 325 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
 326                                                 bool direction, bool sync) {}
 327 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 328                 struct blkio_group *curr_blkg, bool direction, bool sync) {}
 329 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 330                                                 bool direction, bool sync) {}
 331 #endif
 332 #endif /* _BLK_CGROUP_H */