[PATCH v1 33/39] mm/rmap: convert page_dup_file_rmap() to folio_dup_file_rmap_[pte|ptes|pmd]()

David Hildenbrand
2023-12-11T15:59:38Z

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.

Signed-off-by: David Hildenbrand <david@redhat.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 0f4eecd03bdc..df60e44fecad 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -311,6 +311,60 @@ 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_mode mode)
+{
+ __folio_rmap_sanity_checks(folio, page, nr_pages, mode);
+
+ switch (mode) {
+ case RMAP_MODE_PTE:
+ do {
+ atomic_inc(&page->_mapcount);
+ } while (page++, --nr_pages > 0);
+ break;
+ case RMAP_MODE_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_MODE_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_MODE_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)));
@@ -325,11 +379,6 @@ 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 9a5724cf895f..42a0b7b41b86 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -965,7 +965,7 @@ 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)]++;
}

--
2.43.0