Commit 14d01ee9 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm/swapfile: remove page_swapcount() 

By restructuring folio_swapped(), it can use swap_swapcount() instead of
page_swapcount().  It's even a little more efficient.

Link: https://lkml.kernel.org/r/20220902194653.1739778-10-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 907ea17e

mm/swapfile.c

+13 −33
Original line number Diff line number Diff line
@@ -1431,30 +1431,6 @@ void swapcache_free_entries(swp_entry_t *entries, int n) 
		spin_unlock(&p->lock);

}



/*

 * How many references to page are currently swapped out?

 * This does not give an exact answer when swap count is continued,

 * but does include the high COUNT_CONTINUED flag to allow for that.

 */

static int page_swapcount(struct page *page)

{

	int count = 0;

	struct swap_info_struct *p;

	struct swap_cluster_info *ci;

	swp_entry_t entry;

	unsigned long offset;



	entry.val = page_private(page);

	p = _swap_info_get(entry);

	if (p) {

		offset = swp_offset(entry);

		ci = lock_cluster_or_swap_info(p, offset);

		count = swap_count(p->swap_map[offset]);

		unlock_cluster_or_swap_info(p, ci);

	}

	return count;

}



int __swap_count(swp_entry_t entry)

{

	struct swap_info_struct *si;
@@ -1469,11 +1445,16 @@ int __swap_count(swp_entry_t entry) 
	return count;

}



/*

 * How many references to @entry are currently swapped out?

 * This does not give an exact answer when swap count is continued,

 * but does include the high COUNT_CONTINUED flag to allow for that.

 */

static int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry)

{

	int count = 0;

	pgoff_t offset = swp_offset(entry);

	struct swap_cluster_info *ci;

	int count;



	ci = lock_cluster_or_swap_info(si, offset);

	count = swap_count(si->swap_map[offset]);
@@ -1574,17 +1555,16 @@ static bool swap_page_trans_huge_swapped(struct swap_info_struct *si, 


static bool folio_swapped(struct folio *folio)

{

	swp_entry_t entry;

	struct swap_info_struct *si;

	swp_entry_t entry = folio_swap_entry(folio);

	struct swap_info_struct *si = _swap_info_get(entry);



	if (!si)

		return false;



	if (!IS_ENABLED(CONFIG_THP_SWAP) || likely(!folio_test_large(folio)))

		return page_swapcount(&folio->page) != 0;

		return swap_swapcount(si, entry) != 0;



	entry = folio_swap_entry(folio);

	si = _swap_info_get(entry);

	if (si)

	return swap_page_trans_huge_swapped(si, entry);

	return false;

}



/*