LXR linux/drivers/md/dm-stats.h

   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
   9int dm_statistics_init(void);
  10void dm_statistics_exit(void);
  11
  12struct 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
  19struct dm_stats_aux {
  20        bool merged;
  21        unsigned long long duration_ns;
  22};
  23
  24void dm_stats_init(struct dm_stats *st);
  25void dm_stats_cleanup(struct dm_stats *st);
  26
  27struct mapped_device;
  28
  29int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
  30                     char *result, unsigned maxlen);
  31
  32void 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
  37static inline bool dm_stats_used(struct dm_stats *st)
  38{
  39        return !list_empty(&st->list);
  40}
  41
  42static 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