Commit 55ad43e8 authored by Kiryl Shutsemau's avatar Kiryl Shutsemau Committed by Andrew Morton
Browse files

mm: add a helper to accept page 

Accept a given struct page and add it free list.

The help is useful for physical memory scanners that want to use free
unaccepted memory.

Link: https://lkml.kernel.org/r/20240809114854.3745464-7-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 5adfeaec

mm/internal.h

+8 −0
Original line number Diff line number Diff line
@@ -1432,4 +1432,12 @@ unsigned long move_page_tables(struct vm_area_struct *vma, 
	unsigned long new_addr, unsigned long len,

	bool need_rmap_locks, bool for_stack);



#ifdef CONFIG_UNACCEPTED_MEMORY

void accept_page(struct page *page);

#else /* CONFIG_UNACCEPTED_MEMORY */

static inline void accept_page(struct page *page)

{

}

#endif /* CONFIG_UNACCEPTED_MEMORY */



#endif	/* __MM_INTERNAL_H */

mm/page_alloc.c

+35 −12
Original line number Diff line number Diff line
@@ -6935,27 +6935,18 @@ static bool page_contains_unaccepted(struct page *page, unsigned int order) 
	return range_contains_unaccepted_memory(start, PAGE_SIZE << order);

}



static bool try_to_accept_memory_one(struct zone *zone)

static void __accept_page(struct zone *zone, unsigned long *flags,

			  struct page *page)

{

	unsigned long flags;

	struct page *page;

	bool last;



	spin_lock_irqsave(&zone->lock, flags);

	page = list_first_entry_or_null(&zone->unaccepted_pages,

					struct page, lru);

	if (!page) {

		spin_unlock_irqrestore(&zone->lock, flags);

		return false;

	}



	list_del(&page->lru);

	last = list_empty(&zone->unaccepted_pages);



	account_freepages(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);

	__mod_zone_page_state(zone, NR_UNACCEPTED, -MAX_ORDER_NR_PAGES);

	__ClearPageUnaccepted(page);

	spin_unlock_irqrestore(&zone->lock, flags);

	spin_unlock_irqrestore(&zone->lock, *flags);



	accept_memory(page_to_phys(page), PAGE_SIZE << MAX_PAGE_ORDER);
@@ -6963,6 +6954,38 @@ static bool try_to_accept_memory_one(struct zone *zone) 


	if (last)

		static_branch_dec(&zones_with_unaccepted_pages);

}



void accept_page(struct page *page)

{

	struct zone *zone = page_zone(page);

	unsigned long flags;



	spin_lock_irqsave(&zone->lock, flags);

	if (!PageUnaccepted(page)) {

		spin_unlock_irqrestore(&zone->lock, flags);

		return;

	}



	/* Unlocks zone->lock */

	__accept_page(zone, &flags, page);

}



static bool try_to_accept_memory_one(struct zone *zone)

{

	unsigned long flags;

	struct page *page;



	spin_lock_irqsave(&zone->lock, flags);

	page = list_first_entry_or_null(&zone->unaccepted_pages,

					struct page, lru);

	if (!page) {

		spin_unlock_irqrestore(&zone->lock, flags);

		return false;

	}



	/* Unlocks zone->lock */

	__accept_page(zone, &flags, page);



	return true;

}