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 };
 116
 117 struct blkio_group_stats {
 118         /* total disk time and nr sectors dispatched by this group */
 119         uint64_t time;
 120         uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
 121 #ifdef CONFIG_DEBUG_BLK_CGROUP
 122         /* Time not charged to this cgroup */
 123         uint64_t unaccounted_time;
 124
 125         /* Sum of number of IOs queued across all samples */
 126         uint64_t avg_queue_size_sum;
 127         /* Count of samples taken for average */
 128         uint64_t avg_queue_size_samples;
 129         /* How many times this group has been removed from service tree */
 130         unsigned long dequeue;
 131
 132         /* Total time spent waiting for it to be assigned a timeslice. */
 133         uint64_t group_wait_time;
 134         uint64_t start_group_wait_time;
 135
 136         /* Time spent idling for this blkio_group */
 137         uint64_t idle_time;
 138         uint64_t start_idle_time;
 139         /*
 140          * Total time when we have requests queued and do not contain the
 141          * current active queue.
 142          */
 143         uint64_t empty_time;
 144         uint64_t start_empty_time;
 145         uint16_t flags;
 146 #endif
 147 };
 148
 149 /* Per cpu blkio group stats */
 150 struct blkio_group_stats_cpu {
 151         uint64_t sectors;
 152         uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
 153         struct u64_stats_sync syncp;
 154 };
 155
 156 struct blkio_group_conf {
 157         unsigned int weight;
 158         unsigned int iops[2];
 159         u64 bps[2];
 160 };
 161
 162 struct blkio_group {
 163         /* Pointer to the associated request_queue, RCU protected */
 164         struct request_queue __rcu *q;
 165         struct hlist_node blkcg_node;
 166         unsigned short blkcg_id;
 167         /* Store cgroup path */
 168         char path[128];
 169         /* policy which owns this blk group */
 170         enum blkio_policy_id plid;
 171
 172         /* Configuration */
 173         struct blkio_group_conf conf;
 174
 175         /* Need to serialize the stats in the case of reset/update */
 176         spinlock_t stats_lock;
 177         struct blkio_group_stats stats;
 178         /* Per cpu stats pointer */
 179         struct blkio_group_stats_cpu __percpu *stats_cpu;
 180 };
 181
 182 typedef struct blkio_group *(blkio_alloc_group_fn)(struct request_queue *q,
 183                                                    struct blkio_cgroup *blkcg);
 184 typedef void (blkio_link_group_fn)(struct request_queue *q,
 185                         struct blkio_group *blkg);
 186 typedef void (blkio_unlink_group_fn)(struct request_queue *q,
 187                         struct blkio_group *blkg);
 188 typedef bool (blkio_clear_queue_fn)(struct request_queue *q);
 189 typedef void (blkio_update_group_weight_fn)(struct request_queue *q,
 190                         struct blkio_group *blkg, unsigned int weight);
 191 typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q,
 192                         struct blkio_group *blkg, u64 read_bps);
 193 typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q,
 194                         struct blkio_group *blkg, u64 write_bps);
 195 typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q,
 196                         struct blkio_group *blkg, unsigned int read_iops);
 197 typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q,
 198                         struct blkio_group *blkg, unsigned int write_iops);
 199
 200 struct blkio_policy_ops {
 201         blkio_alloc_group_fn *blkio_alloc_group_fn;
 202         blkio_link_group_fn *blkio_link_group_fn;
 203         blkio_unlink_group_fn *blkio_unlink_group_fn;
 204         blkio_clear_queue_fn *blkio_clear_queue_fn;
 205         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
 206         blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
 207         blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
 208         blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
 209         blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
 210 };
 211
 212 struct blkio_policy_type {
 213         struct list_head list;
 214         struct blkio_policy_ops ops;
 215         enum blkio_policy_id plid;
 216 };
 217
 218 /* Blkio controller policy registration */
 219 extern void blkio_policy_register(struct blkio_policy_type *);
 220 extern void blkio_policy_unregister(struct blkio_policy_type *);
 221 extern void blkg_destroy_all(struct request_queue *q);
 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 static inline void blkg_destroy_all(struct request_queue *q) { }
 239
 240 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
 241
 242 #endif
 243
 244 #define BLKIO_WEIGHT_MIN        10
 245 #define BLKIO_WEIGHT_MAX        1000
 246 #define BLKIO_WEIGHT_DEFAULT    500
 247
 248 #ifdef CONFIG_DEBUG_BLK_CGROUP
 249 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
 250 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 251                                 unsigned long dequeue);
 252 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
 253 void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
 254 void blkiocg_set_start_empty_time(struct blkio_group *blkg);
 255
 256 #define BLKG_FLAG_FNS(name)                                             \
 257 static inline void blkio_mark_blkg_##name(                              \
 258                 struct blkio_group_stats *stats)                        \
 259 {                                                                       \
 260         stats->flags |= (1 << BLKG_##name);                             \
 261 }                                                                       \
 262 static inline void blkio_clear_blkg_##name(                             \
 263                 struct blkio_group_stats *stats)                        \
 264 {                                                                       \
 265         stats->flags &= ~(1 << BLKG_##name);                            \
 266 }                                                                       \
 267 static inline int blkio_blkg_##name(struct blkio_group_stats *stats)    \
 268 {                                                                       \
 269         return (stats->flags & (1 << BLKG_##name)) != 0;                \
 270 }                                                                       \
 271
 272 BLKG_FLAG_FNS(waiting)
 273 BLKG_FLAG_FNS(idling)
 274 BLKG_FLAG_FNS(empty)
 275 #undef BLKG_FLAG_FNS
 276 #else
 277 static inline void blkiocg_update_avg_queue_size_stats(
 278                                                 struct blkio_group *blkg) {}
 279 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 280                                                 unsigned long dequeue) {}
 281 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
 282 {}
 283 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
 284 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
 285 #endif
 286
 287 #ifdef CONFIG_BLK_CGROUP
 288 extern struct blkio_cgroup blkio_root_cgroup;
 289 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
 290 extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
 291 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 292 extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
 293                                        struct request_queue *q,
 294                                        enum blkio_policy_id plid);
 295 struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
 296                                        struct request_queue *q,
 297                                        enum blkio_policy_id plid,
 298                                        bool for_root);
 299 void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 300                                         unsigned long time,
 301                                         unsigned long unaccounted_time);
 302 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
 303                                                 bool direction, bool sync);
 304 void blkiocg_update_completion_stats(struct blkio_group *blkg,
 305         uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
 306 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
 307                                         bool sync);
 308 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 309                 struct blkio_group *curr_blkg, bool direction, bool sync);
 310 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 311                                         bool direction, bool sync);
 312 #else
 313 struct cgroup;
 314 static inline struct blkio_cgroup *
 315 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
 316 static inline struct blkio_cgroup *
 317 task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
 318
 319 static inline int
 320 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
 321
 322 static inline struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
 323                                               void *key) { return NULL; }
 324 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
 325                                                 unsigned long time,
 326                                                 unsigned long unaccounted_time)
 327 {}
 328 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
 329                                 uint64_t bytes, bool direction, bool sync) {}
 330 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
 331                 uint64_t start_time, uint64_t io_start_time, bool direction,
 332                 bool sync) {}
 333 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
 334                                                 bool direction, bool sync) {}
 335 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 336                 struct blkio_group *curr_blkg, bool direction, bool sync) {}
 337 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 338                                                 bool direction, bool sync) {}
 339 #endif
 340 #endif /* _BLK_CGROUP_H */