diff options
| -rw-r--r-- | include/linux/mm_types.h | 2 | ||||
| -rw-r--r-- | include/linux/page-flags.h | 11 | ||||
| -rw-r--r-- | mm/ksm.c | 19 | ||||
| -rw-r--r-- | mm/migrate.c | 3 | ||||
| -rw-r--r-- | mm/shmem.c | 11 |
5 files changed, 22 insertions, 24 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 2419e60c9a7f..6e3bdf8e38bc 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -109,7 +109,7 @@ struct page { /** * @private: Mapping-private opaque data. * Usually used for buffer_heads if PagePrivate. - * Used for swp_entry_t if PageSwapCache. + * Used for swp_entry_t if swapcache flag set. * Indicates order in the buddy system if PageBuddy. */ unsigned long private; diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 71444223d630..b31d2c50b6f0 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -574,15 +574,10 @@ static __always_inline bool folio_test_swapcache(const struct folio *folio) test_bit(PG_swapcache, const_folio_flags(folio, 0)); } -static __always_inline bool PageSwapCache(const struct page *page) -{ - return folio_test_swapcache(page_folio(page)); -} - -SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) -CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) +FOLIO_SET_FLAG(swapcache, FOLIO_HEAD_PAGE) +FOLIO_CLEAR_FLAG(swapcache, FOLIO_HEAD_PAGE) #else -PAGEFLAG_FALSE(SwapCache, swapcache) +FOLIO_FLAG_FALSE(swapcache) #endif PAGEFLAG(Unevictable, unevictable, PF_HEAD) @@ -909,12 +909,13 @@ again: */ while (!folio_try_get(folio)) { /* - * Another check for page->mapping != expected_mapping would - * work here too. We have chosen the !PageSwapCache test to - * optimize the common case, when the page is or is about to - * be freed: PageSwapCache is cleared (under spin_lock_irq) - * in the ref_freeze section of __remove_mapping(); but Anon - * folio->mapping reset to NULL later, in free_pages_prepare(). + * Another check for folio->mapping != expected_mapping + * would work here too. We have chosen to test the + * swapcache flag to optimize the common case, when the + * folio is or is about to be freed: the swapcache flag + * is cleared (under spin_lock_irq) in the ref_freeze + * section of __remove_mapping(); but anon folio->mapping + * is reset to NULL later, in free_pages_prepare(). */ if (!folio_test_swapcache(folio)) goto stale; @@ -945,7 +946,7 @@ again: stale: /* - * We come here from above when page->mapping or !PageSwapCache + * We come here from above when folio->mapping or the swapcache flag * suggests that the node is stale; but it might be under migration. * We need smp_rmb(), matching the smp_wmb() in folio_migrate_ksm(), * before checking whether node->kpfn has been changed. @@ -1452,7 +1453,7 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, goto out; /* - * We need the page lock to read a stable PageSwapCache in + * We need the folio lock to read a stable swapcache flag in * write_protect_page(). We use trylock_page() instead of * lock_page() because we don't want to wait here - we * prefer to continue scanning and merging different pages, @@ -3123,7 +3124,7 @@ void folio_migrate_ksm(struct folio *newfolio, struct folio *folio) * newfolio->mapping was set in advance; now we need smp_wmb() * to make sure that the new stable_node->kpfn is visible * to ksm_get_folio() before it can see that folio->mapping - * has gone stale (or that folio_test_swapcache has been cleared). + * has gone stale (or that the swapcache flag has been cleared). */ smp_wmb(); folio_set_stable_node(folio, NULL); diff --git a/mm/migrate.c b/mm/migrate.c index 76cfc6c42eb3..2250baa85ac2 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -639,7 +639,8 @@ void folio_migrate_flags(struct folio *newfolio, struct folio *folio) folio_migrate_ksm(newfolio, folio); /* * Please do not reorder this without considering how mm/ksm.c's - * ksm_get_folio() depends upon ksm_migrate_page() and PageSwapCache(). + * ksm_get_folio() depends upon ksm_migrate_page() and the + * swapcache flag. */ if (folio_test_swapcache(folio)) folio_clear_swapcache(folio); diff --git a/mm/shmem.c b/mm/shmem.c index 1448a7a9a282..866d46d0c43d 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -502,8 +502,8 @@ static int shmem_replace_entry(struct address_space *mapping, * Sometimes, before we decide whether to proceed or to fail, we must check * that an entry was not already brought back from swap by a racing thread. * - * Checking page is not enough: by the time a SwapCache page is locked, it - * might be reused, and again be SwapCache, using the same swap as before. + * Checking folio is not enough: by the time a swapcache folio is locked, it + * might be reused, and again be swapcache, using the same swap as before. */ static bool shmem_confirm_swap(struct address_space *mapping, pgoff_t index, swp_entry_t swap) @@ -1965,9 +1965,10 @@ static int shmem_replace_folio(struct folio **foliop, gfp_t gfp, if (unlikely(error)) { /* - * Is this possible? I think not, now that our callers check - * both PageSwapCache and page_private after getting page lock; - * but be defensive. Reverse old to newpage for clear and free. + * Is this possible? I think not, now that our callers + * check both the swapcache flag and folio->private + * after getting the folio lock; but be defensive. + * Reverse old to newpage for clear and free. */ old = new; } else { |