4 * Common Block IO controller cgroup interface
6 * Based on ideas and code from CFQ, CFS and BFQ:
7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
9 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
10 * Paolo Valente <paolo.valente@unimore.it>
12 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
13 * Nauman Rafique <nauman@google.com>
16 #include <linux/cgroup.h>
18 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
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
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 */
35 /* Total time spent waiting in scheduler queue in ns */
37 /* Number of IOs merged */
39 /* Number of IOs queued up */
41 /* All the single valued stats go below this */
44 #ifdef CONFIG_DEBUG_BLK_CGROUP
45 BLKIO_STAT_AVG_QUEUE_SIZE
,
47 BLKIO_STAT_EMPTY_TIME
,
48 BLKIO_STAT_GROUP_WAIT_TIME
,
61 /* blkg state flags */
62 enum blkg_state_flags
{
69 struct cgroup_subsys_state css
;
72 struct hlist_head blkg_list
;
73 struct list_head policy_list
; /* list of blkio_policy_node */
76 struct blkio_group_stats
{
77 /* total disk time and nr sectors dispatched by this group */
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
;
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
;
93 /* Time spent idling for this blkio_group */
95 uint64_t start_idle_time
;
97 * Total time when we have requests queued and do not contain the
98 * current active queue.
101 uint64_t start_empty_time
;
107 /* An rcu protected unique identifier for the group */
109 struct hlist_node blkcg_node
;
110 unsigned short blkcg_id
;
111 #ifdef CONFIG_DEBUG_BLK_CGROUP
112 /* Store cgroup path */
115 /* The device MKDEV(major, minor), this group has been created for */
118 /* Need to serialize the stats in the case of reset/update */
119 spinlock_t stats_lock
;
120 struct blkio_group_stats stats
;
123 struct blkio_policy_node
{
124 struct list_head node
;
129 extern unsigned int blkcg_get_weight(struct blkio_cgroup
*blkcg
,
132 typedef void (blkio_unlink_group_fn
) (void *key
, struct blkio_group
*blkg
);
133 typedef void (blkio_update_group_weight_fn
) (struct blkio_group
*blkg
,
134 unsigned int weight
);
136 struct blkio_policy_ops
{
137 blkio_unlink_group_fn
*blkio_unlink_group_fn
;
138 blkio_update_group_weight_fn
*blkio_update_group_weight_fn
;
141 struct blkio_policy_type
{
142 struct list_head list
;
143 struct blkio_policy_ops ops
;
146 /* Blkio controller policy registration */
147 extern void blkio_policy_register(struct blkio_policy_type
*);
148 extern void blkio_policy_unregister(struct blkio_policy_type
*);
155 struct blkio_policy_type
{
158 static inline void blkio_policy_register(struct blkio_policy_type
*blkiop
) { }
159 static inline void blkio_policy_unregister(struct blkio_policy_type
*blkiop
) { }
163 #define BLKIO_WEIGHT_MIN 100
164 #define BLKIO_WEIGHT_MAX 1000
165 #define BLKIO_WEIGHT_DEFAULT 500
167 #ifdef CONFIG_DEBUG_BLK_CGROUP
168 static inline char *blkg_path(struct blkio_group
*blkg
)
172 void blkiocg_update_avg_queue_size_stats(struct blkio_group
*blkg
);
173 void blkiocg_update_dequeue_stats(struct blkio_group
*blkg
,
174 unsigned long dequeue
);
175 void blkiocg_update_set_idle_time_stats(struct blkio_group
*blkg
);
176 void blkiocg_update_idle_time_stats(struct blkio_group
*blkg
);
177 void blkiocg_set_start_empty_time(struct blkio_group
*blkg
, bool ignore
);
179 #define BLKG_FLAG_FNS(name) \
180 static inline void blkio_mark_blkg_##name( \
181 struct blkio_group_stats *stats) \
183 stats->flags |= (1 << BLKG_##name); \
185 static inline void blkio_clear_blkg_##name( \
186 struct blkio_group_stats *stats) \
188 stats->flags &= ~(1 << BLKG_##name); \
190 static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
192 return (stats->flags & (1 << BLKG_##name)) != 0; \
195 BLKG_FLAG_FNS(waiting)
196 BLKG_FLAG_FNS(idling
)
200 static inline char *blkg_path(struct blkio_group
*blkg
) { return NULL
; }
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
)
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
,
212 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
213 extern struct blkio_cgroup blkio_root_cgroup
;
214 extern struct blkio_cgroup
*cgroup_to_blkio_cgroup(struct cgroup
*cgroup
);
215 extern void blkiocg_add_blkio_group(struct blkio_cgroup
*blkcg
,
216 struct blkio_group
*blkg
, void *key
, dev_t dev
);
217 extern int blkiocg_del_blkio_group(struct blkio_group
*blkg
);
218 extern struct blkio_group
*blkiocg_lookup_group(struct blkio_cgroup
*blkcg
,
220 void blkio_group_init(struct blkio_group
*blkg
);
221 void blkiocg_update_timeslice_used(struct blkio_group
*blkg
,
223 void blkiocg_update_dispatch_stats(struct blkio_group
*blkg
, uint64_t bytes
,
224 bool direction
, bool sync
);
225 void blkiocg_update_completion_stats(struct blkio_group
*blkg
,
226 uint64_t start_time
, uint64_t io_start_time
, bool direction
, bool sync
);
227 void blkiocg_update_io_merged_stats(struct blkio_group
*blkg
, bool direction
,
229 void blkiocg_update_io_add_stats(struct blkio_group
*blkg
,
230 struct blkio_group
*curr_blkg
, bool direction
, bool sync
);
231 void blkiocg_update_io_remove_stats(struct blkio_group
*blkg
,
232 bool direction
, bool sync
);
235 static inline struct blkio_cgroup
*
236 cgroup_to_blkio_cgroup(struct cgroup
*cgroup
) { return NULL
; }
238 static inline void blkio_group_init(struct blkio_group
*blkg
) {}
239 static inline void blkiocg_add_blkio_group(struct blkio_cgroup
*blkcg
,
240 struct blkio_group
*blkg
, void *key
, dev_t dev
) {}
243 blkiocg_del_blkio_group(struct blkio_group
*blkg
) { return 0; }
245 static inline struct blkio_group
*
246 blkiocg_lookup_group(struct blkio_cgroup
*blkcg
, void *key
) { return NULL
; }
247 static inline void blkiocg_update_timeslice_used(struct blkio_group
*blkg
,
248 unsigned long time
) {}
249 static inline void blkiocg_update_dispatch_stats(struct blkio_group
*blkg
,
250 uint64_t bytes
, bool direction
, bool sync
) {}
251 static inline void blkiocg_update_completion_stats(struct blkio_group
*blkg
,
252 uint64_t start_time
, uint64_t io_start_time
, bool direction
,
254 static inline void blkiocg_update_io_merged_stats(struct blkio_group
*blkg
,
255 bool direction
, bool sync
) {}
256 static inline void blkiocg_update_io_add_stats(struct blkio_group
*blkg
,
257 struct blkio_group
*curr_blkg
, bool direction
, bool sync
) {}
258 static inline void blkiocg_update_io_remove_stats(struct blkio_group
*blkg
,
259 bool direction
, bool sync
) {}
261 #endif /* _BLK_CGROUP_H */