1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef DM_STATS_H
3 #define DM_STATS_H
4
5 #include <linux/types.h>
6 #include <linux/mutex.h>
7 #include <linux/list.h>
8
9 int dm_statistics_init(void);
10 void dm_statistics_exit(void);
11
12 struct dm_stats {
13 struct mutex mutex;
14 struct list_head list; /* list of struct dm_stat */
15 struct dm_stats_last_position __percpu *last;
16 bool precise_timestamps;
17 };
18
19 struct dm_stats_aux {
20 bool merged;
21 unsigned long long duration_ns;
22 };
23
24 void dm_stats_init(struct dm_stats *st);
25 void dm_stats_cleanup(struct dm_stats *st);
26
27 struct mapped_device;
28
29 int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
30 char *result, unsigned maxlen);
31
32 void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
33 sector_t bi_sector, unsigned bi_sectors, bool end,
34 unsigned long start_time,
35 struct dm_stats_aux *aux);
36
dm_stats_used(struct dm_stats * st)37 static inline bool dm_stats_used(struct dm_stats *st)
38 {
39 return !list_empty(&st->list);
40 }
41
dm_stats_record_start(struct dm_stats * stats,struct dm_stats_aux * aux)42 static inline void dm_stats_record_start(struct dm_stats *stats, struct dm_stats_aux *aux)
43 {
44 if (unlikely(stats->precise_timestamps))
45 aux->duration_ns = ktime_to_ns(ktime_get());
46 }
47
48 #endif
49