Commit 5bf34d7c authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm: Add folio_test_pmd_mappable() 



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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarWilliam Kucharski <william.kucharski@oracle.com>
parent 821979f5

include/linux/huge_mm.h

+14 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/mm.h

+21 −21
Original line number Diff line number Diff line
@@ -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)

{

	/*