diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 1e330f2998f..2a97fafa3d8 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -344,7 +344,7 @@ int can_share_swap_page(struct page *page) * Work out if there are any other processes sharing this * swap cache page. Free it if you can. Return success. */ -int remove_exclusive_swap_page(struct page *page) +static int remove_exclusive_swap_page_count(struct page *page, int count) { int retval; struct swap_info_struct * p; @@ -357,7 +357,7 @@ int remove_exclusive_swap_page(struct page *page) return 0; if (PageWriteback(page)) return 0; - if (page_count(page) != 2) /* 2: us + cache */ + if (page_count(page) != count) /* us + cache + ptes */ return 0; entry.val = page_private(page); @@ -370,7 +370,7 @@ int remove_exclusive_swap_page(struct page *page) if (p->swap_map[swp_offset(entry)] == 1) { /* Recheck the page count with the swapcache lock held.. */ spin_lock_irq(&swapper_space.tree_lock); - if ((page_count(page) == 2) && !PageWriteback(page)) { + if ((page_count(page) == count) && !PageWriteback(page)) { __delete_from_swap_cache(page); SetPageDirty(page); retval = 1; @@ -388,6 +388,25 @@ int remove_exclusive_swap_page(struct page *page) } /* + * Most of the time the page should have two references: one for the + * process and one for the swap cache. + */ +int remove_exclusive_swap_page(struct page *page) +{ + return remove_exclusive_swap_page_count(page, 2); +} + +/* + * The pageout code holds an extra reference to the page. That raises + * the reference count to test for to 2 for a page that is only in the + * swap cache plus 1 for each process that maps the page. + */ +int remove_exclusive_swap_page_ref(struct page *page) +{ + return remove_exclusive_swap_page_count(page, 2 + page_mapcount(page)); +} + +/* * Free the swap entry like above, but also try to * free the page cache entry if it is the last user. */ |