Commit d4b4084a authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm: Turn can_split_huge_page() into can_split_folio() 



This function already required a head page to be passed, so this
just adds type-safety and removes a few implicit calls to
compound_head().

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
parent e0cd5e7f

include/linux/huge_mm.h

+2 −2
Original line number Diff line number Diff line
@@ -185,7 +185,7 @@ void prep_transhuge_page(struct page *page); 
void free_transhuge_page(struct page *page);

bool is_transparent_hugepage(struct page *page);



bool can_split_huge_page(struct page *page, int *pextra_pins);

bool can_split_folio(struct folio *folio, int *pextra_pins);

int split_huge_page_to_list(struct page *page, struct list_head *list);

static inline int split_huge_page(struct page *page)

{
@@ -387,7 +387,7 @@ static inline bool is_transparent_hugepage(struct page *page) 
#define thp_get_unmapped_area	NULL



static inline bool

can_split_huge_page(struct page *page, int *pextra_pins)

can_split_folio(struct folio *folio, int *pextra_pins)

{

	BUILD_BUG();

	return false;

mm/huge_memory.c

+8 −7
Original line number Diff line number Diff line
@@ -2516,18 +2516,19 @@ int page_trans_huge_mapcount(struct page *page) 
}



/* Racy check whether the huge page can be split */

bool can_split_huge_page(struct page *page, int *pextra_pins)

bool can_split_folio(struct folio *folio, int *pextra_pins)

{

	int extra_pins;



	/* Additional pins from page cache */

	if (PageAnon(page))

		extra_pins = PageSwapCache(page) ? thp_nr_pages(page) : 0;

	if (folio_test_anon(folio))

		extra_pins = folio_test_swapcache(folio) ?

				folio_nr_pages(folio) : 0;

	else

		extra_pins = thp_nr_pages(page);

		extra_pins = folio_nr_pages(folio);

	if (pextra_pins)

		*pextra_pins = extra_pins;

	return total_mapcount(page) == page_count(page) - extra_pins - 1;

	return folio_mapcount(folio) == folio_ref_count(folio) - extra_pins - 1;

}



/*
@@ -2619,7 +2620,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) 
	 * Racy check if we can split the page, before unmap_page() will

	 * split PMDs

	 */

	if (!can_split_huge_page(head, &extra_pins)) {

	if (!can_split_folio(folio, &extra_pins)) {

		ret = -EBUSY;

		goto out_unlock;

	}
@@ -2928,7 +2929,7 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start, 
			goto next;



		total++;

		if (!can_split_huge_page(compound_head(page), NULL))

		if (!can_split_folio(page_folio(page), NULL))

			goto next;



		if (!trylock_page(page))

mm/vmscan.c

+3 −3
Original line number Diff line number Diff line
@@ -1703,18 +1703,18 @@ static unsigned int shrink_page_list(struct list_head *page_list, 
			if (!PageSwapCache(page)) {

				if (!(sc->gfp_mask & __GFP_IO))

					goto keep_locked;

				if (page_maybe_dma_pinned(page))

				if (folio_maybe_dma_pinned(folio))

					goto keep_locked;

				if (PageTransHuge(page)) {

					/* cannot split THP, skip it */

					if (!can_split_huge_page(page, NULL))

					if (!can_split_folio(folio, NULL))

						goto activate_locked;

					/*

					 * Split pages without a PMD map right

					 * away. Chances are some or all of the

					 * tail pages can be freed without IO.

					 */

					if (!compound_mapcount(page) &&

					if (!folio_entire_mapcount(folio) &&

					    split_folio_to_list(folio,

								page_list))

						goto activate_locked;