From: David Hildenbrand david@redhat.com
mainline inclusion from mainline-6.8-rc1 commit d8ef5e311d7bfde54b60ab45026f206eff31b2d2 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9CESE CVE: NA
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Let's convert page_dup_file_rmap() like the other rmap functions. As there is only a single caller, convert that single caller right away and remove page_dup_file_rmap().
Add folio_dup_file_rmap_ptes() right away, we want to perform rmap baching during fork() soon.
Link: https://lkml.kernel.org/r/20231220224504.646757-34-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Cc: Hugh Dickins hughd@google.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Muchun Song muchun.song@linux.dev Cc: Muchun Song songmuchun@bytedance.com Cc: Peter Xu peterx@redhat.com Cc: Ryan Roberts ryan.roberts@arm.com Cc: Yin Fengwei fengwei.yin@intel.com Signed-off-by: Andrew Morton akpm@linux-foundation.org (cherry picked from commit d8ef5e311d7bfde54b60ab45026f206eff31b2d2) Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com --- include/linux/rmap.h | 59 ++++++++++++++++++++++++++++++++++++++++---- mm/memory.c | 2 +- 2 files changed, 55 insertions(+), 6 deletions(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 4741c964866e..8f369fb3ed71 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -305,6 +305,60 @@ static inline void hugetlb_remove_rmap(struct folio *folio) atomic_dec(&folio->_entire_mapcount); }
+static __always_inline void __folio_dup_file_rmap(struct folio *folio, + struct page *page, int nr_pages, enum rmap_level level) +{ + __folio_rmap_sanity_checks(folio, page, nr_pages, level); + + switch (level) { + case RMAP_LEVEL_PTE: + do { + atomic_inc(&page->_mapcount); + } while (page++, --nr_pages > 0); + break; + case RMAP_LEVEL_PMD: + atomic_inc(&folio->_entire_mapcount); + break; + } +} + +/** + * folio_dup_file_rmap_ptes - duplicate PTE mappings of a page range of a folio + * @folio: The folio to duplicate the mappings of + * @page: The first page to duplicate the mappings of + * @nr_pages: The number of pages of which the mapping will be duplicated + * + * The page range of the folio is defined by [page, page + nr_pages) + * + * The caller needs to hold the page table lock. + */ +static inline void folio_dup_file_rmap_ptes(struct folio *folio, + struct page *page, int nr_pages) +{ + __folio_dup_file_rmap(folio, page, nr_pages, RMAP_LEVEL_PTE); +} +#define folio_dup_file_rmap_pte(folio, page) \ + folio_dup_file_rmap_ptes(folio, page, 1) + +/** + * folio_dup_file_rmap_pmd - duplicate a PMD mapping of a page range of a folio + * @folio: The folio to duplicate the mapping of + * @page: The first page to duplicate the mapping of + * + * The page range of the folio is defined by [page, page + HPAGE_PMD_NR) + * + * The caller needs to hold the page table lock. + */ +static inline void folio_dup_file_rmap_pmd(struct folio *folio, + struct page *page) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + __folio_dup_file_rmap(folio, page, HPAGE_PMD_NR, RMAP_LEVEL_PTE); +#else + WARN_ON_ONCE(true); +#endif +} + static inline void __page_dup_rmap(struct page *page, bool compound) { VM_WARN_ON(folio_test_hugetlb(page_folio(page))); @@ -319,11 +373,6 @@ static inline void __page_dup_rmap(struct page *page, bool compound) } }
-static inline void page_dup_file_rmap(struct page *page, bool compound) -{ - __page_dup_rmap(page, compound); -} - /** * page_try_dup_anon_rmap - try duplicating a mapping of an already mapped * anonymous page diff --git a/mm/memory.c b/mm/memory.c index d60144b822a1..3beb0ef1688d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -968,7 +968,7 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, rss[MM_ANONPAGES]++; } else if (page) { folio_get(folio); - page_dup_file_rmap(page, false); + folio_dup_file_rmap_pte(folio, page); rss[mm_counter_file(page)]++; add_reliable_folio_counter(folio, dst_vma->vm_mm, 1); }