2.4.13-ac8

 mm

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla/mm/swap_state.c linux.ac/mm/swap_state.c
--- linux.vanilla/mm/swap_state.c   Thu Oct 11 13:52:14 2001
+++ linux.ac/mm/swap_state.c   Fri Nov  2 14:52:58 2001
@@ -70,18 +70,24 @@
 
 int add_to_swap_cache(struct page *page, swp_entry_t entry)
 {
+   int referenced;
+
    if (page->mapping)
       BUG();
    if (!swap_duplicate(entry)) {
       INC_CACHE_INFO(noent_race);
       return -ENOENT;
    }
+   page->age = PAGE_AGE_START;
+   referenced = PageReferenced(page);
    if (add_to_page_cache_unique(page, &swapper_space, entry.val,
          page_hash(&swapper_space, entry.val)) != 0) {
       swap_free(entry);
       INC_CACHE_INFO(exist_race);
       return -EEXIST;
    }
+   if (referenced)
+      SetPageReferenced(page);
    SetPageUptodate(page);
    if (!PageLocked(page))
       BUG();
@@ -156,6 +162,29 @@
 }
 
 /*
+ * Like the above, but used to clean up the non-resident pages of
+ * a process. If the page exists but we couldn't get the trylock,
+ * the pageout code will remove the page later.
+ */
+void free_swap_and_swap_cache(swp_entry_t entry)
+{
+   struct page * page;
+
+   /* Free our own reference to the swap space */
+   swap_free(entry);
+
+   /* If the swapcache is the only remaining user, free that too. */
+   page = find_trylock_page(&swapper_space, entry.val);
+   if (page) {
+      if (exclusive_swap_page(page)) {
+         delete_from_swap_cache(page);
+      }
+      UnlockPage(page);
+      page_cache_release(page);
+   }
+}
+
+/*
  * Lookup a swap entry in the swap cache. A found page will be returned
  * unlocked and with its refcount incremented - we rely on the kernel
  * lock getting page table operations atomic even if we drop the page
@@ -173,8 +202,10 @@
     * that, but no need to change: we _have_ got the right page.
     */
    INC_CACHE_INFO(find_total);
-   if (found)
+   if (found) {
+      touch_page(found);
       INC_CACHE_INFO(find_success);
+   }
    return found;
 }