diff options
Diffstat (limited to 'mm/swap.h')
| -rw-r--r-- | mm/swap.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/mm/swap.h b/mm/swap.h index f8711ff82f84..ad2f121de970 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -80,6 +80,32 @@ static inline unsigned int folio_swap_flags(struct folio *folio) { return swp_swap_info(folio->swap)->flags; } + +/* + * Return the count of contiguous swap entries that share the same + * zeromap status as the starting entry. If is_zeromap is not NULL, + * it will return the zeromap status of the starting entry. + */ +static inline int swap_zeromap_batch(swp_entry_t entry, int max_nr, + bool *is_zeromap) +{ + struct swap_info_struct *sis = swp_swap_info(entry); + unsigned long start = swp_offset(entry); + unsigned long end = start + max_nr; + bool first_bit; + + first_bit = test_bit(start, sis->zeromap); + if (is_zeromap) + *is_zeromap = first_bit; + + if (max_nr <= 1) + return max_nr; + if (first_bit) + return find_next_zero_bit(sis->zeromap, end, start) - start; + else + return find_next_bit(sis->zeromap, end, start) - start; +} + #else /* CONFIG_SWAP */ struct swap_iocb; static inline void swap_read_folio(struct folio *folio, struct swap_iocb **plug) @@ -171,6 +197,13 @@ static inline unsigned int folio_swap_flags(struct folio *folio) { return 0; } + +static inline int swap_zeromap_batch(swp_entry_t entry, int max_nr, + bool *has_zeromap) +{ + return 0; +} + #endif /* CONFIG_SWAP */ #endif /* _MM_SWAP_H */ |