X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fmigrate.c;h=e2fdbce1874b4ff7a481621b6c5a3285d8d75260;hb=f15f41383d466860f8b22f669da8c841f8d73c3b;hp=e9b161bde95b4c382092a1c94a8fcfbd4bcf58f0;hpb=b361735043e3001eadb1d40916fd1a4fca1a9363;p=pandora-kernel.git

diff --git a/mm/migrate.c b/mm/migrate.c
index e9b161bde95b..e2fdbce1874b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -49,9 +49,8 @@ int isolate_lru_page(struct page *page, struct list_head *pagelist)
 		struct zone *zone = page_zone(page);
 
 		spin_lock_irq(&zone->lru_lock);
-		if (PageLRU(page)) {
+		if (PageLRU(page) && get_page_unless_zero(page)) {
 			ret = 0;
-			get_page(page);
 			ClearPageLRU(page);
 			if (PageActive(page))
 				del_page_from_active_list(zone, page);
@@ -297,7 +296,7 @@ static int migrate_page_move_mapping(struct address_space *mapping,
 	void **pslot;
 
 	if (!mapping) {
-		/* Anonymous page */
+		/* Anonymous page without mapping */
 		if (page_count(page) != 1)
 			return -EAGAIN;
 		return 0;
@@ -333,6 +332,19 @@ static int migrate_page_move_mapping(struct address_space *mapping,
 	 */
 	__put_page(page);
 
+	/*
+	 * If moved to a different zone then also account
+	 * the page for that zone. Other VM counters will be
+	 * taken care of when we establish references to the
+	 * new page and drop references to the old page.
+	 *
+	 * Note that anonymous pages are accounted for
+	 * via NR_FILE_PAGES and NR_ANON_PAGES if they
+	 * are mapped to swap space.
+	 */
+	__dec_zone_page_state(page, NR_FILE_PAGES);
+	__inc_zone_page_state(newpage, NR_FILE_PAGES);
+
 	write_unlock_irq(&mapping->tree_lock);
 
 	return 0;
@@ -599,6 +611,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 	int rc = 0;
 	int *result = NULL;
 	struct page *newpage = get_new_page(page, private, &result);
+	int rcu_locked = 0;
 
 	if (!newpage)
 		return -ENOMEM;
@@ -619,18 +632,41 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 			goto unlock;
 		wait_on_page_writeback(page);
 	}
-
 	/*
-	 * Establish migration ptes or remove ptes
+	 * By try_to_unmap(), page->mapcount goes down to 0 here. In this case,
+	 * we cannot notice that anon_vma is freed while we migrates a page.
+	 * This rcu_read_lock() delays freeing anon_vma pointer until the end
+	 * of migration. File cache pages are no problem because of page_lock()
+	 * File Caches may use write_page() or lock_page() in migration, then,
+	 * just care Anon page here.
+	 */
+	if (PageAnon(page)) {
+		rcu_read_lock();
+		rcu_locked = 1;
+	}
+	/*
+	 * This is a corner case handling.
+	 * When a new swap-cache is read into, it is linked to LRU
+	 * and treated as swapcache but has no rmap yet.
+	 * Calling try_to_unmap() against a page->mapping==NULL page is
+	 * BUG. So handle it here.
 	 */
+	if (!page->mapping)
+		goto rcu_unlock;
+	/* Establish migration ptes or remove ptes */
 	try_to_unmap(page, 1);
+
 	if (!page_mapped(page))
 		rc = move_to_new_page(newpage, page);
 
 	if (rc)
 		remove_migration_ptes(page, page);
+rcu_unlock:
+	if (rcu_locked)
+		rcu_read_unlock();
 
 unlock:
+
 	unlock_page(page);
 
 	if (rc != -EAGAIN) {
@@ -748,7 +784,8 @@ static struct page *new_page_node(struct page *p, unsigned long private,
 
 	*result = &pm->status;
 
-	return alloc_pages_node(pm->node, GFP_HIGHUSER | GFP_THISNODE, 0);
+	return alloc_pages_node(pm->node,
+				GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
 }
 
 /*
@@ -781,7 +818,7 @@ static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm,
 
 		err = -EFAULT;
 		vma = find_vma(mm, pp->addr);
-		if (!vma)
+		if (!vma || !vma_migratable(vma))
 			goto set_status;
 
 		page = follow_page(vma, pp->addr, FOLL_GET);