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-rw-r--r--mm/migrate.c75
1 files changed, 3 insertions, 72 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 0a011e421bb4d8..81721a061d50a4 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -70,10 +70,6 @@ int isolate_lru_page(struct page *page, struct list_head *pagelist)
*/
int migrate_prep(void)
{
- /* Must have swap device for migration */
- if (nr_swap_pages <= 0)
- return -ENODEV;
-
/*
* Clear the LRU lists so pages can be isolated.
* Note that pages may be moved off the LRU after we have
@@ -246,52 +242,6 @@ out:
}
/*
- * swapout a single page
- * page is locked upon entry, unlocked on exit
- */
-static int swap_page(struct page *page)
-{
- struct address_space *mapping = page_mapping(page);
-
- if (page_mapped(page) && mapping)
- if (try_to_unmap(page, 1) != SWAP_SUCCESS)
- goto unlock_retry;
-
- if (PageDirty(page)) {
- /* Page is dirty, try to write it out here */
- switch(pageout(page, mapping)) {
- case PAGE_KEEP:
- case PAGE_ACTIVATE:
- goto unlock_retry;
-
- case PAGE_SUCCESS:
- goto retry;
-
- case PAGE_CLEAN:
- ; /* try to free the page below */
- }
- }
-
- if (PagePrivate(page)) {
- if (!try_to_release_page(page, GFP_KERNEL) ||
- (!mapping && page_count(page) == 1))
- goto unlock_retry;
- }
-
- if (remove_mapping(mapping, page)) {
- /* Success */
- unlock_page(page);
- return 0;
- }
-
-unlock_retry:
- unlock_page(page);
-
-retry:
- return -EAGAIN;
-}
-
-/*
* Replace the page in the mapping.
*
* The number of remaining references must be:
@@ -517,8 +467,7 @@ static int fallback_migrate_page(struct address_space *mapping,
* Two lists are passed to this function. The first list
* contains the pages isolated from the LRU to be migrated.
* The second list contains new pages that the pages isolated
- * can be moved to. If the second list is NULL then all
- * pages are swapped out.
+ * can be moved to.
*
* The function returns after 10 attempts or if no pages
* are movable anymore because to has become empty
@@ -574,29 +523,11 @@ redo:
* Only wait on writeback if we have already done a pass where
* we we may have triggered writeouts for lots of pages.
*/
- if (pass > 0) {
+ if (pass > 0)
wait_on_page_writeback(page);
- } else {
+ else
if (PageWriteback(page))
goto unlock_page;
- }
-
- /*
- * Anonymous pages must have swap cache references otherwise
- * the information contained in the page maps cannot be
- * preserved.
- */
- if (PageAnon(page) && !PageSwapCache(page)) {
- if (!add_to_swap(page, GFP_KERNEL)) {
- rc = -ENOMEM;
- goto unlock_page;
- }
- }
-
- if (!to) {
- rc = swap_page(page);
- goto next;
- }
/*
* Establish swap ptes for anonymous pages or destroy pte