Commit 5beaee54 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm: add is_huge_zero_folio() 

This is the folio equivalent of is_huge_zero_page().  It doesn't add any
efficiency, but it does prevent the caller from passing a tail page and
getting confused when the predicate returns false.

Link: https://lkml.kernel.org/r/20240326202833.523759-3-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 4d30eac3

fs/proc/page.c

+1 −1
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ u64 stable_page_flags(const struct page *page) 
	else if (folio_test_large(folio)) {

		if ((k & (1 << PG_lru)) || is_anon)

			u |= 1 << KPF_THP;

		else if (is_huge_zero_page(&folio->page)) {

		else if (is_huge_zero_folio(folio)) {

			u |= 1 << KPF_ZERO_PAGE;

			u |= 1 << KPF_THP;

		}

include/linux/huge_mm.h

+10 −0
Original line number Diff line number Diff line
@@ -356,6 +356,11 @@ static inline bool is_huge_zero_page(const struct page *page) 
	return READ_ONCE(huge_zero_page) == page;

}



static inline bool is_huge_zero_folio(const struct folio *folio)

{

	return READ_ONCE(huge_zero_page) == &folio->page;

}



static inline bool is_huge_zero_pmd(pmd_t pmd)

{

	return pmd_present(pmd) && READ_ONCE(huge_zero_pfn) == pmd_pfn(pmd);
@@ -485,6 +490,11 @@ static inline bool is_huge_zero_page(const struct page *page) 
	return false;

}



static inline bool is_huge_zero_folio(const struct folio *folio)

{

	return false;

}



static inline bool is_huge_zero_pmd(pmd_t pmd)

{

	return false;

mm/huge_memory.c

+3 −3
Original line number Diff line number Diff line
@@ -789,12 +789,12 @@ struct deferred_split *get_deferred_split_queue(struct folio *folio) 
}

#endif



static inline bool is_transparent_hugepage(struct folio *folio)

static inline bool is_transparent_hugepage(const struct folio *folio)

{

	if (!folio_test_large(folio))

		return false;



	return is_huge_zero_page(&folio->page) ||

	return is_huge_zero_folio(folio) ||

		folio_test_large_rmappable(folio);

}
@@ -3085,7 +3085,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, 
	}





	is_hzp = is_huge_zero_page(&folio->page);

	is_hzp = is_huge_zero_folio(folio);

	if (is_hzp) {

		pr_warn_ratelimited("Called split_huge_page for huge zero page\n");

		return -EBUSY;

mm/mempolicy.c

+1 −1
Original line number Diff line number Diff line
@@ -510,7 +510,7 @@ static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk) 
		return;

	}

	folio = pfn_folio(pmd_pfn(*pmd));

	if (is_huge_zero_page(&folio->page)) {

	if (is_huge_zero_folio(folio)) {

		walk->action = ACTION_CONTINUE;

		return;

	}

mm/swap.c

+1 −1
Original line number Diff line number Diff line
@@ -985,7 +985,7 @@ void folios_put_refs(struct folio_batch *folios, unsigned int *refs) 
		struct folio *folio = folios->folios[i];

		unsigned int nr_refs = refs ? refs[i] : 1;



		if (is_huge_zero_page(&folio->page))

		if (is_huge_zero_folio(folio))

			continue;



		if (folio_is_zone_device(folio)) {