Commit 4d510f3d authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm: add folio_add_new_anon_rmap() 

In contrast to other rmap functions, page_add_new_anon_rmap() is always
called with a freshly allocated page.  That means it can't be called with
a tail page.  Turn page_add_new_anon_rmap() into folio_add_new_anon_rmap()
and add a page_add_new_anon_rmap() wrapper.  Callers can be converted
individually.

[akpm@linux-foundation.org: fix NOMMU build.  page_add_new_anon_rmap() requires CONFIG_MMU]
[willy@infradead.org: folio-compat.c needs rmap.h]
Link: https://lkml.kernel.org/r/20230111142915.1001531-9-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent eb01a2ad

include/linux/rmap.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -194,6 +194,8 @@ void page_add_anon_rmap(struct page *, struct vm_area_struct *, 
		unsigned long address, rmap_t flags);

		unsigned long address, rmap_t flags);

void page_add_new_anon_rmap(struct page *, struct vm_area_struct *,

void page_add_new_anon_rmap(struct page *, struct vm_area_struct *,

		unsigned long address);

		unsigned long address);

void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *,

		unsigned long address);

void page_add_file_rmap(struct page *, struct vm_area_struct *,

void page_add_file_rmap(struct page *, struct vm_area_struct *,

		bool compound);

		bool compound);

void page_remove_rmap(struct page *, struct vm_area_struct *,

void page_remove_rmap(struct page *, struct vm_area_struct *,

mm/folio-compat.c

+11 −0
Original line number Original line Diff line number Diff line
@@ -6,6 +6,7 @@ 




#include <linux/migrate.h>

#include <linux/migrate.h>

#include <linux/pagemap.h>

#include <linux/pagemap.h>

#include <linux/rmap.h>

#include <linux/swap.h>

#include <linux/swap.h>

#include "internal.h"

#include "internal.h"
@@ -123,3 +124,13 @@ void putback_lru_page(struct page *page) 
{

{

	folio_putback_lru(page_folio(page));

	folio_putback_lru(page_folio(page));

}

}



#ifdef CONFIG_MMU

void page_add_new_anon_rmap(struct page *page, struct vm_area_struct *vma,

		unsigned long address)

{

	VM_BUG_ON_PAGE(PageTail(page), page);



	return folio_add_new_anon_rmap((struct folio *)page, vma, address);

}

#endif

mm/rmap.c

+18 −19
Original line number Original line Diff line number Diff line
@@ -1264,41 +1264,40 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, 
}

}





/**

/**

 * page_add_new_anon_rmap - add mapping to a new anonymous page

 * folio_add_new_anon_rmap - Add mapping to a new anonymous folio.

 * @page:	the page to add the mapping to

 * @folio:	The folio to add the mapping to.

 * @vma:	the vm area in which the mapping is added

 * @vma:	the vm area in which the mapping is added

 * @address:	the user virtual address mapped

 * @address:	the user virtual address mapped

 *

 *

 * If it's a compound page, it is accounted as a compound page. As the page

 * Like page_add_anon_rmap() but must only be called on *new* folios.

 * is new, it's assume to get mapped exclusively by a single process.

 *

 * Same as page_add_anon_rmap but must only be called on *new* pages.

 * This means the inc-and-test can be bypassed.

 * This means the inc-and-test can be bypassed.

 * Page does not have to be locked.

 * The folio does not have to be locked.

 *

 * If the folio is large, it is accounted as a THP.  As the folio

 * is new, it's assumed to be mapped exclusively by a single process.

 */

 */

void page_add_new_anon_rmap(struct page *page,

void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,

	struct vm_area_struct *vma, unsigned long address)

		unsigned long address)

{

{

	int nr;

	int nr;





	VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);

	VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);

	__SetPageSwapBacked(page);

	__folio_set_swapbacked(folio);





	if (likely(!PageCompound(page))) {

	if (likely(!folio_test_pmd_mappable(folio))) {

		/* increment count (starts at -1) */

		/* increment count (starts at -1) */

		atomic_set(&page->_mapcount, 0);

		atomic_set(&folio->_mapcount, 0);

		nr = 1;

		nr = 1;

	} else {

	} else {

		VM_BUG_ON_PAGE(!PageTransHuge(page), page);

		/* increment count (starts at -1) */

		/* increment count (starts at -1) */

		atomic_set(compound_mapcount_ptr(page), 0);

		atomic_set(&folio->_entire_mapcount, 0);

		atomic_set(subpages_mapcount_ptr(page), COMPOUND_MAPPED);

		atomic_set(&folio->_nr_pages_mapped, COMPOUND_MAPPED);

		nr = thp_nr_pages(page);

		nr = folio_nr_pages(folio);

		__mod_lruvec_page_state(page, NR_ANON_THPS, nr);

		__lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr);

	}

	}





	__mod_lruvec_page_state(page, NR_ANON_MAPPED, nr);

	__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);

	__page_set_anon_rmap(page, vma, address, 1);

	__page_set_anon_rmap(&folio->page, vma, address, 1);

}

}





/**

/**