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 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE) 19 20 #ifndef CONFIG_BLK_CGROUP 21 /* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */ 22 extern struct cgroup_subsys blkio_subsys; 23 #define blkio_subsys_id blkio_subsys.subsys_id 24 #endif 25 26 enum stat_type { 27 /* Total time spent (in ns) between request dispatch to the driver and 28 * request completion for IOs doen by this cgroup. This may not be 29 * accurate when NCQ is turned on. */ 30 BLKIO_STAT_SERVICE_TIME = 0, 31 /* Total bytes transferred */ 32 BLKIO_STAT_SERVICE_BYTES, 33 /* Total IOs serviced, post merge */ 34 BLKIO_STAT_SERVICED, 35 /* Total time spent waiting in scheduler queue in ns */ 36 BLKIO_STAT_WAIT_TIME, 37 /* Number of IOs merged */ 38 BLKIO_STAT_MERGED, 39 /* Number of IOs queued up */ 40 BLKIO_STAT_QUEUED, 41 /* All the single valued stats go below this */ 42 BLKIO_STAT_TIME, 43 BLKIO_STAT_SECTORS, 44 #ifdef CONFIG_DEBUG_BLK_CGROUP 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 enum stat_sub_type { 54 BLKIO_STAT_READ = 0, 55 BLKIO_STAT_WRITE, 56 BLKIO_STAT_SYNC, 57 BLKIO_STAT_ASYNC, 58 BLKIO_STAT_TOTAL 59 }; 60 61 /* blkg state flags */ 62 enum blkg_state_flags { 63 BLKG_waiting = 0, 64 BLKG_idling, 65 BLKG_empty, 66 }; 67 68 struct blkio_cgroup { 69 struct cgroup_subsys_state css; 70 unsigned int weight; 71 spinlock_t lock; 72 struct hlist_head blkg_list; 73 struct list_head policy_list; /* list of blkio_policy_node */ 74 }; 75 76 struct blkio_group_stats { 77 /* total disk time and nr sectors dispatched by this group */ 78 uint64_t time; 79 uint64_t sectors; 80 uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL]; 81 #ifdef CONFIG_DEBUG_BLK_CGROUP 82 /* Sum of number of IOs queued across all samples */ 83 uint64_t avg_queue_size_sum; 84 /* Count of samples taken for average */ 85 uint64_t avg_queue_size_samples; 86 /* How many times this group has been removed from service tree */ 87 unsigned long dequeue; 88 89 /* Total time spent waiting for it to be assigned a timeslice. */ 90 uint64_t group_wait_time; 91 uint64_t start_group_wait_time; 92 93 /* Time spent idling for this blkio_group */ 94 uint64_t idle_time; 95 uint64_t start_idle_time; 96 /* 97 * Total time when we have requests queued and do not contain the 98 * current active queue. 99 */ 100 uint64_t empty_time; 101 uint64_t start_empty_time; 102 uint16_t flags; 103 #endif 104 }; 105 106 struct blkio_group { 107 /* An rcu protected unique identifier for the group */ 108 void *key; 109 struct hlist_node blkcg_node; 110 unsigned short blkcg_id; 111 /* Store cgroup path */ 112 char path[128]; 113 /* The device MKDEV(major, minor), this group has been created for */ 114 dev_t dev; 115 116 /* Need to serialize the stats in the case of reset/update */ 117 spinlock_t stats_lock; 118 struct blkio_group_stats stats; 119 }; 120 121 struct blkio_policy_node { 122 struct list_head node; 123 dev_t dev; 124 unsigned int weight; 125 }; 126 127 extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, 128 dev_t dev); 129 130 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg); 131 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg, 132 unsigned int weight); 133 134 struct blkio_policy_ops { 135 blkio_unlink_group_fn *blkio_unlink_group_fn; 136 blkio_update_group_weight_fn *blkio_update_group_weight_fn; 137 }; 138 139 struct blkio_policy_type { 140 struct list_head list; 141 struct blkio_policy_ops ops; 142 }; 143 144 /* Blkio controller policy registration */ 145 extern void blkio_policy_register(struct blkio_policy_type *); 146 extern void blkio_policy_unregister(struct blkio_policy_type *); 147 148 static inline char *blkg_path(struct blkio_group *blkg) 149 { 150 return blkg->path; 151 } 152 153 #else 154 155 struct blkio_group { 156 }; 157 158 struct blkio_policy_type { 159 }; 160 161 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { } 162 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } 163 164 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } 165 166 #endif 167 168 #define BLKIO_WEIGHT_MIN 100 169 #define BLKIO_WEIGHT_MAX 1000 170 #define BLKIO_WEIGHT_DEFAULT 500 171 172 #ifdef CONFIG_DEBUG_BLK_CGROUP 173 void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg); 174 void blkiocg_update_dequeue_stats(struct blkio_group *blkg, 175 unsigned long dequeue); 176 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg); 177 void blkiocg_update_idle_time_stats(struct blkio_group *blkg); 178 void blkiocg_set_start_empty_time(struct blkio_group *blkg); 179 180 #define BLKG_FLAG_FNS(name) \ 181 static inline void blkio_mark_blkg_##name( \ 182 struct blkio_group_stats *stats) \ 183 { \ 184 stats->flags |= (1 << BLKG_##name); \ 185 } \ 186 static inline void blkio_clear_blkg_##name( \ 187 struct blkio_group_stats *stats) \ 188 { \ 189 stats->flags &= ~(1 << BLKG_##name); \ 190 } \ 191 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \ 192 { \ 193 return (stats->flags & (1 << BLKG_##name)) != 0; \ 194 } \ 195 196 BLKG_FLAG_FNS(waiting) 197 BLKG_FLAG_FNS(idling) 198 BLKG_FLAG_FNS(empty) 199 #undef BLKG_FLAG_FNS 200 #else 201 static inline void blkiocg_update_avg_queue_size_stats( 202 struct blkio_group *blkg) {} 203 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg, 204 unsigned long dequeue) {} 205 static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) 206 {} 207 static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {} 208 static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {} 209 #endif 210 211 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE) 212 extern struct blkio_cgroup blkio_root_cgroup; 213 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup); 214 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, 215 struct blkio_group *blkg, void *key, dev_t dev); 216 extern int blkiocg_del_blkio_group(struct blkio_group *blkg); 217 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, 218 void *key); 219 void blkiocg_update_timeslice_used(struct blkio_group *blkg, 220 unsigned long time); 221 void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes, 222 bool direction, bool sync); 223 void blkiocg_update_completion_stats(struct blkio_group *blkg, 224 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync); 225 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction, 226 bool sync); 227 void blkiocg_update_io_add_stats(struct blkio_group *blkg, 228 struct blkio_group *curr_blkg, bool direction, bool sync); 229 void blkiocg_update_io_remove_stats(struct blkio_group *blkg, 230 bool direction, bool sync); 231 #else 232 struct cgroup; 233 static inline struct blkio_cgroup * 234 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; } 235 236 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, 237 struct blkio_group *blkg, void *key, dev_t dev) {} 238 239 static inline int 240 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; } 241 242 static inline struct blkio_group * 243 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; } 244 static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg, 245 unsigned long time) {} 246 static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg, 247 uint64_t bytes, bool direction, bool sync) {} 248 static inline void blkiocg_update_completion_stats(struct blkio_group *blkg, 249 uint64_t start_time, uint64_t io_start_time, bool direction, 250 bool sync) {} 251 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg, 252 bool direction, bool sync) {} 253 static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg, 254 struct blkio_group *curr_blkg, bool direction, bool sync) {} 255 static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg, 256 bool direction, bool sync) {} 257 #endif 258 #endif /* _BLK_CGROUP_H */ 259