diff options
| -rw-r--r-- | include/linux/swapfile.h | 2 | ||||
| -rw-r--r-- | include/linux/swapops.h | 7 | ||||
| -rw-r--r-- | mm/swapfile.c | 8 |
3 files changed, 11 insertions, 6 deletions
diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h index e2d11ae4e73d..7ed529a77c5b 100644 --- a/include/linux/swapfile.h +++ b/include/linux/swapfile.h @@ -12,5 +12,7 @@ unsigned long arch_max_swapfile_size(void); /* Maximum swapfile size supported for the arch (not inclusive). */ extern unsigned long swapfile_maximum_size; +/* Whether swap migration entry supports storing A/D bits for the arch */ +extern bool swap_migration_ad_supported; #endif /* _LINUX_SWAPFILE_H */ diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 027b4095e132..86b95ccb81bb 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -301,13 +301,8 @@ static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) */ static inline bool migration_entry_supports_ad(void) { - /* - * max_swapfile_size() returns the max supported swp-offset plus 1. - * We can support the migration A/D bits iff the pfn swap entry has - * the offset large enough to cover all of them (PFN, A & D bits). - */ #ifdef CONFIG_SWAP - return swapfile_maximum_size >= (1UL << SWP_MIG_TOTAL_BITS); + return swap_migration_ad_supported; #else /* CONFIG_SWAP */ return false; #endif /* CONFIG_SWAP */ diff --git a/mm/swapfile.c b/mm/swapfile.c index 3cc64399df44..263b19e693cf 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -64,6 +64,9 @@ EXPORT_SYMBOL_GPL(nr_swap_pages); long total_swap_pages; static int least_priority = -1; unsigned long swapfile_maximum_size; +#ifdef CONFIG_MIGRATION +bool swap_migration_ad_supported; +#endif /* CONFIG_MIGRATION */ static const char Bad_file[] = "Bad swap file entry "; static const char Unused_file[] = "Unused swap file entry "; @@ -3680,6 +3683,11 @@ static int __init swapfile_init(void) swapfile_maximum_size = arch_max_swapfile_size(); +#ifdef CONFIG_MIGRATION + if (swapfile_maximum_size >= (1UL << SWP_MIG_TOTAL_BITS)) + swap_migration_ad_supported = true; +#endif /* CONFIG_MIGRATION */ + return 0; } subsys_initcall(swapfile_init); |