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