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 | int 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 int argc, char **argv, |
30 | char *result, unsigned int maxlen); |
31 | |
32 | void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw, |
33 | sector_t bi_sector, unsigned int bi_sectors, bool end, |
34 | unsigned long start_time, |
35 | struct dm_stats_aux *aux); |
36 | |
37 | static inline bool dm_stats_used(struct dm_stats *st) |
38 | { |
39 | return !list_empty(head: &st->list); |
40 | } |
41 | |
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(kt: ktime_get()); |
46 | } |
47 | |
48 | #endif |
49 | |