diff options
| -rw-r--r-- | mm/zsmalloc.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 626f09fb2713..b12250e219bb 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -877,7 +877,6 @@ static void reset_zpdesc(struct zpdesc *zpdesc) { struct page *page = zpdesc_page(zpdesc); - __ClearPageMovable(page); ClearPagePrivate(page); zpdesc->zspage = NULL; zpdesc->next = NULL; @@ -1716,10 +1715,11 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage, static bool zs_page_isolate(struct page *page, isolate_mode_t mode) { /* - * Page is locked so zspage couldn't be destroyed. For detail, look at - * lock_zspage in free_zspage. + * Page is locked so zspage can't be destroyed concurrently + * (see free_zspage()). But if the page was already destroyed + * (see reset_zpdesc()), refuse isolation here. */ - return true; + return page_zpdesc(page)->zspage; } static int zs_page_migrate(struct page *newpage, struct page *page, @@ -1737,6 +1737,16 @@ static int zs_page_migrate(struct page *newpage, struct page *page, unsigned long old_obj, new_obj; unsigned int obj_idx; + /* + * TODO: nothing prevents a zspage from getting destroyed while + * it is isolated for migration, as the page lock is temporarily + * dropped after zs_page_isolate() succeeded: we should rework that + * and defer destroying such pages once they are un-isolated (putback) + * instead. + */ + if (!zpdesc->zspage) + return MIGRATEPAGE_SUCCESS; + /* The page is locked, so this pointer must remain valid */ zspage = get_zspage(zpdesc); pool = zspage->pool; |