Commit 593a10da authored by Kefeng Wang's avatar Kefeng Wang Committed by Andrew Morton
Browse files

mm: refactor folio_undo_large_rmappable() 

Folios of order <= 1 are not in deferred list, the check of order is added
into folio_undo_large_rmappable() from commit 8897277a ("mm: support
order-1 folios in the page cache"), but there is a repeated check for
small folio (order 0) during each call of the
folio_undo_large_rmappable(), so only keep folio_order() check inside the
function.

In addition, move all the checks into header file to save a function call
for non-large-rmappable or empty deferred_list folio.

Link: https://lkml.kernel.org/r/20240521130315.46072-1-wangkefeng.wang@huawei.com


Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarVishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8bf890c8

mm/huge_memory.c

+1 −12
Original line number Diff line number Diff line
@@ -3258,22 +3258,11 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, 
	return ret;

}



void folio_undo_large_rmappable(struct folio *folio)

void __folio_undo_large_rmappable(struct folio *folio)

{

	struct deferred_split *ds_queue;

	unsigned long flags;



	if (folio_order(folio) <= 1)

		return;



	/*

	 * At this point, there is no one trying to add the folio to

	 * deferred_list. If folio is not in deferred_list, it's safe

	 * to check without acquiring the split_queue_lock.

	 */

	if (data_race(list_empty(&folio->_deferred_list)))

		return;



	ds_queue = get_deferred_split_queue(folio);

	spin_lock_irqsave(&ds_queue->split_queue_lock, flags);

	if (!list_empty(&folio->_deferred_list)) {

mm/internal.h

+16 −1
Original line number Diff line number Diff line
@@ -622,7 +622,22 @@ static inline void folio_set_order(struct folio *folio, unsigned int order) 
#endif

}



void folio_undo_large_rmappable(struct folio *folio);

void __folio_undo_large_rmappable(struct folio *folio);

static inline void folio_undo_large_rmappable(struct folio *folio)

{

	if (folio_order(folio) <= 1 || !folio_test_large_rmappable(folio))

		return;



	/*

	 * At this point, there is no one trying to add the folio to

	 * deferred_list. If folio is not in deferred_list, it's safe

	 * to check without acquiring the split_queue_lock.

	 */

	if (data_race(list_empty(&folio->_deferred_list)))

		return;



	__folio_undo_large_rmappable(folio);

}



static inline struct folio *page_rmappable_folio(struct page *page)

{

mm/page_alloc.c

+1 −2
Original line number Diff line number Diff line
@@ -2661,7 +2661,6 @@ void free_unref_folios(struct folio_batch *folios) 
		unsigned long pfn = folio_pfn(folio);

		unsigned int order = folio_order(folio);



		if (order > 0 && folio_test_large_rmappable(folio))

		folio_undo_large_rmappable(folio);

		if (!free_pages_prepare(&folio->page, order))

			continue;

mm/swap.c

+2 −6
Original line number Diff line number Diff line
@@ -123,7 +123,6 @@ void __folio_put(struct folio *folio) 
	}



	page_cache_release(folio);

	if (folio_test_large(folio) && folio_test_large_rmappable(folio))

	folio_undo_large_rmappable(folio);

	mem_cgroup_uncharge(folio);

	free_unref_page(&folio->page, folio_order(folio));
@@ -1002,10 +1001,7 @@ void folios_put_refs(struct folio_batch *folios, unsigned int *refs) 
			free_huge_folio(folio);

			continue;

		}

		if (folio_test_large(folio) &&

		    folio_test_large_rmappable(folio))

		folio_undo_large_rmappable(folio);



		__page_cache_release(folio, &lruvec, &flags);



		if (j != i)

mm/vmscan.c

+2 −6
Original line number Diff line number Diff line
@@ -1439,8 +1439,6 @@ static unsigned int shrink_folio_list(struct list_head *folio_list, 
		 */

		nr_reclaimed += nr_pages;



		if (folio_test_large(folio) &&

		    folio_test_large_rmappable(folio))

		folio_undo_large_rmappable(folio);

		if (folio_batch_add(&free_folios, folio) == 0) {

			mem_cgroup_uncharge_folios(&free_folios);
@@ -1848,8 +1846,6 @@ static unsigned int move_folios_to_lru(struct lruvec *lruvec, 
		if (unlikely(folio_put_testzero(folio))) {

			__folio_clear_lru_flags(folio);



			if (folio_test_large(folio) &&

			    folio_test_large_rmappable(folio))

			folio_undo_large_rmappable(folio);

			if (folio_batch_add(&free_folios, folio) == 0) {

				spin_unlock_irq(&lruvec->lru_lock);