h63xx: initial omap board support.

[linux-2.6-omap-h63xx.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1e330f2998fa259d2733f73f4c50ce0d649c5dc0..90cb67a5417cccea9f0352b6316f747bec4c608d 100644 (file)
--- 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;
@@ -387,6 +387,25 @@ int remove_exclusive_swap_page(struct page *page)
        return retval;
 }
 
+/*
+ * 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.
@@ -403,7 +422,7 @@ void free_swap_and_cache(swp_entry_t entry)
        if (p) {
                if (swap_entry_free(p, swp_offset(entry)) == 1) {
                        page = find_get_page(&swapper_space, entry.val);
-                       if (page && unlikely(!trylock_page(page))) {
+                       if (page && !trylock_page(page)) {
                                page_cache_release(page);
                                page = NULL;
                        }