mm: balloon: use general non-lru movable page feature

Now, VM has a feature to migrate non-lru movable pages so balloon
doesn't need custom migration hooks in migrate.c and compaction.c.

Instead, this patch implements the page->mapping->a_ops->
{isolate|migrate|putback} functions.

With that, we could remove hooks for ballooning in general migration
functions and make balloon compaction simple.

[akpm@linux-foundation.org: compaction.h requires that the includer first include node.h]
Link: http://lkml.kernel.org/r/1464736881-24886-4-git-send-email-minchan@kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 17 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 8119fdc563f8..f278005f609c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -170,14 +170,12 @@ void putback_movable_pages(struct list_head *l)
 		list_del(&page->lru);
 		dec_zone_page_state(page, NR_ISOLATED_ANON +
 				page_is_file_cache(page));
-		if (unlikely(isolated_balloon_page(page))) {
-			balloon_page_putback(page);
 		/*
 		 * We isolated non-lru movable page so here we can use
 		 * __PageMovable because LRU page's mapping cannot have
 		 * PAGE_MAPPING_MOVABLE.
 		 */
-		} else if (unlikely(__PageMovable(page))) {
+		if (unlikely(__PageMovable(page))) {
 			VM_BUG_ON_PAGE(!PageIsolated(page), page);
 			lock_page(page);
 			if (PageMovable(page))
@@ -992,18 +990,6 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 	if (unlikely(!trylock_page(newpage)))
 		goto out_unlock;
 
-	if (unlikely(isolated_balloon_page(page))) {
-		/*
-		 * A ballooned page does not need any special attention from
-		 * physical to virtual reverse mapping procedures.
-		 * Skip any attempt to unmap PTEs or to remap swap cache,
-		 * in order to avoid burning cycles at rmap level, and perform
-		 * the page migration right away (proteced by page lock).
-		 */
-		rc = balloon_page_migrate(newpage, page, mode);
-		goto out_unlock_both;
-	}
-
 	if (unlikely(!is_lru)) {
 		rc = move_to_new_page(newpage, page, mode);
 		goto out_unlock_both;
@@ -1058,8 +1044,7 @@ out:
 	 * list in here.
 	 */
 	if (rc == MIGRATEPAGE_SUCCESS) {
-		if (unlikely(__is_movable_balloon_page(newpage) ||
-				__PageMovable(newpage)))
+		if (unlikely(__PageMovable(newpage)))
 			put_page(newpage);
 		else
 			putback_lru_page(newpage);