Root/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
18enum 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 */
30extern struct cgroup_subsys blkio_subsys;
31#define blkio_subsys_id blkio_subsys.subsys_id
32#endif
33
34enum 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
61enum 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 */
70enum blkg_state_flags {
71    BLKG_waiting = 0,
72    BLKG_idling,
73    BLKG_empty,
74};
75
76/* cgroup files owned by proportional weight policy */
77enum 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 */
96enum 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
105struct 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
113struct 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
143struct 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
160struct 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
180extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
181                     dev_t dev);
182extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
183                     dev_t dev);
184extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
185                     dev_t dev);
186extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
187                     dev_t dev);
188extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
189                     dev_t dev);
190
191typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
192
193typedef void (blkio_update_group_weight_fn) (void *key,
194            struct blkio_group *blkg, unsigned int weight);
195typedef void (blkio_update_group_read_bps_fn) (void * key,
196            struct blkio_group *blkg, u64 read_bps);
197typedef void (blkio_update_group_write_bps_fn) (void *key,
198            struct blkio_group *blkg, u64 write_bps);
199typedef void (blkio_update_group_read_iops_fn) (void *key,
200            struct blkio_group *blkg, unsigned int read_iops);
201typedef void (blkio_update_group_write_iops_fn) (void *key,
202            struct blkio_group *blkg, unsigned int write_iops);
203
204struct 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
213struct 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 */
220extern void blkio_policy_register(struct blkio_policy_type *);
221extern void blkio_policy_unregister(struct blkio_policy_type *);
222
223static inline char *blkg_path(struct blkio_group *blkg)
224{
225    return blkg->path;
226}
227
228#else
229
230struct blkio_group {
231};
232
233struct blkio_policy_type {
234};
235
236static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
237static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
238
239static 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
248void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
249void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
250                unsigned long dequeue);
251void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
252void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
253void blkiocg_set_start_empty_time(struct blkio_group *blkg);
254
255#define BLKG_FLAG_FNS(name) \
256static inline void blkio_mark_blkg_##name( \
257        struct blkio_group_stats *stats) \
258{ \
259    stats->flags |= (1 << BLKG_##name); \
260} \
261static inline void blkio_clear_blkg_##name( \
262        struct blkio_group_stats *stats) \
263{ \
264    stats->flags &= ~(1 << BLKG_##name); \
265} \
266static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
267{ \
268    return (stats->flags & (1 << BLKG_##name)) != 0; \
269} \
270
271BLKG_FLAG_FNS(waiting)
272BLKG_FLAG_FNS(idling)
273BLKG_FLAG_FNS(empty)
274#undef BLKG_FLAG_FNS
275#else
276static inline void blkiocg_update_avg_queue_size_stats(
277                        struct blkio_group *blkg) {}
278static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
279                        unsigned long dequeue) {}
280static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
281{}
282static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
283static 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)
287extern struct blkio_cgroup blkio_root_cgroup;
288extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
289extern 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);
292extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
293extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
294                        void *key);
295void blkiocg_update_timeslice_used(struct blkio_group *blkg,
296                    unsigned long time);
297void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
298                        bool direction, bool sync);
299void blkiocg_update_completion_stats(struct blkio_group *blkg,
300    uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
301void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
302                    bool sync);
303void blkiocg_update_io_add_stats(struct blkio_group *blkg,
304        struct blkio_group *curr_blkg, bool direction, bool sync);
305void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
306                    bool direction, bool sync);
307#else
308struct cgroup;
309static inline struct blkio_cgroup *
310cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
311
312static 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
316static inline int
317blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
318
319static inline struct blkio_group *
320blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
321static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
322                        unsigned long time) {}
323static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
324                uint64_t bytes, bool direction, bool sync) {}
325static 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) {}
328static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
329                        bool direction, bool sync) {}
330static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
331        struct blkio_group *curr_blkg, bool direction, bool sync) {}
332static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
333                        bool direction, bool sync) {}
334#endif
335#endif /* _BLK_CGROUP_H */
336

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