Add a predicate to determine if the folio might be mapped by a PMD entry.
If CONFIG_TRANSPARENT_HUGEPAGE is disabled, we know it can't be, even
if it's large enough.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/huge_mm.h | 14 ++++++++++++++
include/linux/mm.h | 42 ++++++++++++++++++++---------------------
2 files changed, 35 insertions(+), 21 deletions(-)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index f280f33ff223..e4c18ba8d3bf 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -274,6 +274,15 @@ static inline int thp_nr_pages(struct page *page)
return 1;
}
+/**
+ * folio_test_pmd_mappable - Can we map this folio with a PMD?
+ * @folio: The folio to test
+ */
+static inline bool folio_test_pmd_mappable(struct folio *folio)
+{
+ return folio_order(folio) >= HPAGE_PMD_ORDER;
+}
+
struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd, int flags, struct dev_pagemap **pgmap);
struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
@@ -339,6 +348,11 @@ static inline int thp_nr_pages(struct page *page)
return 1;
}
+static inline bool folio_test_pmd_mappable(struct folio *folio)
+{
+ return false;
+}
+
static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
{
return false;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a7e4a9e7d807..72ca04f16711 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -714,6 +714,27 @@ int vma_is_stack_for_current(struct vm_area_struct *vma);
struct mmu_gather;
struct inode;
+static inline unsigned int compound_order(struct page *page)
+{
+ if (!PageHead(page))
+ return 0;
+ return page[1].compound_order;
+}
+
+/**
+ * folio_order - The allocation order of a folio.
+ * @folio: The folio.
+ *
+ * A folio is composed of 2^order pages. See get_order() for the definition
+ * of order.
+ *
+ * Return: The order of the folio.
+ */
+static inline unsigned int folio_order(struct folio *folio)
+{
+ return compound_order(&folio->page);
+}
+
#include <linux/huge_mm.h>
/*
@@ -906,27 +927,6 @@ static inline void destroy_compound_page(struct page *page)
compound_page_dtors[page[1].compound_dtor](page);
}
-static inline unsigned int compound_order(struct page *page)
-{
- if (!PageHead(page))
- return 0;
- return page[1].compound_order;
-}
-
-/**
- * folio_order - The allocation order of a folio.
- * @folio: The folio.
- *
- * A folio is composed of 2^order pages. See get_order() for the definition
- * of order.
- *
- * Return: The order of the folio.
- */
-static inline unsigned int folio_order(struct folio *folio)
-{
- return compound_order(&folio->page);
-}
-
static inline bool hpage_pincount_available(struct page *page)
{
/*
--
2.33.0
