From 5beaee54a324ba1fe307e341ec825d5d099f4091 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 26 Mar 2024 20:28:22 +0000 Subject: [PATCH] mm: add is_huge_zero_folio() This is the folio equivalent of is_huge_zero_page(). It doesn't add any efficiency, but it does prevent the caller from passing a tail page and getting confused when the predicate returns false. Link: https://lkml.kernel.org/r/20240326202833.523759-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Signed-off-by: Andrew Morton --- fs/proc/page.c | 2 +- include/linux/huge_mm.h | 10 ++++++++++ mm/huge_memory.c | 6 +++--- mm/mempolicy.c | 2 +- mm/swap.c | 2 +- mm/swap_state.c | 2 +- mm/userfaultfd.c | 2 +- 7 files changed, 18 insertions(+), 8 deletions(-) diff --git a/fs/proc/page.c b/fs/proc/page.c index 05120263af2a..2fb64bdb64eb 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -155,7 +155,7 @@ u64 stable_page_flags(const struct page *page) else if (folio_test_large(folio)) { if ((k & (1 << PG_lru)) || is_anon) u |= 1 << KPF_THP; - else if (is_huge_zero_page(&folio->page)) { + else if (is_huge_zero_folio(folio)) { u |= 1 << KPF_ZERO_PAGE; u |= 1 << KPF_THP; } diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 1540a1481daf..600c6008262b 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -356,6 +356,11 @@ static inline bool is_huge_zero_page(const struct page *page) return READ_ONCE(huge_zero_page) == page; } +static inline bool is_huge_zero_folio(const struct folio *folio) +{ + return READ_ONCE(huge_zero_page) == &folio->page; +} + static inline bool is_huge_zero_pmd(pmd_t pmd) { return pmd_present(pmd) && READ_ONCE(huge_zero_pfn) == pmd_pfn(pmd); @@ -485,6 +490,11 @@ static inline bool is_huge_zero_page(const struct page *page) return false; } +static inline bool is_huge_zero_folio(const struct folio *folio) +{ + return false; +} + static inline bool is_huge_zero_pmd(pmd_t pmd) { return false; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 75ad971ca45e..5c043c7b5062 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -789,12 +789,12 @@ struct deferred_split *get_deferred_split_queue(struct folio *folio) } #endif -static inline bool is_transparent_hugepage(struct folio *folio) +static inline bool is_transparent_hugepage(const struct folio *folio) { if (!folio_test_large(folio)) return false; - return is_huge_zero_page(&folio->page) || + return is_huge_zero_folio(folio) || folio_test_large_rmappable(folio); } @@ -3085,7 +3085,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, } - is_hzp = is_huge_zero_page(&folio->page); + is_hzp = is_huge_zero_folio(folio); if (is_hzp) { pr_warn_ratelimited("Called split_huge_page for huge zero page\n"); return -EBUSY; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 913cff5da5a3..5743028a63a5 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -510,7 +510,7 @@ static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk) return; } folio = pfn_folio(pmd_pfn(*pmd)); - if (is_huge_zero_page(&folio->page)) { + if (is_huge_zero_folio(folio)) { walk->action = ACTION_CONTINUE; return; } diff --git a/mm/swap.c b/mm/swap.c index 500a09a48dfd..f72364e92d5f 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -985,7 +985,7 @@ void folios_put_refs(struct folio_batch *folios, unsigned int *refs) struct folio *folio = folios->folios[i]; unsigned int nr_refs = refs ? refs[i] : 1; - if (is_huge_zero_page(&folio->page)) + if (is_huge_zero_folio(folio)) continue; if (folio_is_zone_device(folio)) { diff --git a/mm/swap_state.c b/mm/swap_state.c index bfc7e8c58a6d..2deac23633cd 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -301,7 +301,7 @@ void free_page_and_swap_cache(struct page *page) struct folio *folio = page_folio(page); free_swap_cache(folio); - if (!is_huge_zero_page(page)) + if (!is_huge_zero_folio(folio)) folio_put(folio); } diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 3c3539c573e7..a0ec14553fbe 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -1664,7 +1664,7 @@ ssize_t move_pages(struct userfaultfd_ctx *ctx, unsigned long dst_start, !pmd_none(dst_pmdval)) { struct folio *folio = pfn_folio(pmd_pfn(*src_pmd)); - if (!folio || (!is_huge_zero_page(&folio->page) && + if (!folio || (!is_huge_zero_folio(folio) && !PageAnonExclusive(&folio->page))) { spin_unlock(ptl); err = -EBUSY;