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