[PATCH v1 03/29] mm/zsmalloc: drop PageIsolated() related VM_BUG_ONs

David Hildenbrand
2025-06-30T13:00:29Z

Let's drop these checks; these are conditions the core migration code
must make sure will hold either way, no need to double check.

Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
mm/zpdesc.h | 5 -----
mm/zsmalloc.c | 5 -----
2 files changed, 10 deletions(-)

diff --git a/mm/zpdesc.h b/mm/zpdesc.h
index d3df316e5bb7b..5cb7e3de43952 100644
--- a/mm/zpdesc.h
+++ b/mm/zpdesc.h
@@ -168,11 +168,6 @@ static inline void __zpdesc_clear_zsmalloc(struct zpdesc *zpdesc)
__ClearPageZsmalloc(zpdesc_page(zpdesc));
}

-static inline bool zpdesc_is_isolated(struct zpdesc *zpdesc)
-{
- return PageIsolated(zpdesc_page(zpdesc));
-}
-
static inline struct zone *zpdesc_zone(struct zpdesc *zpdesc)
{
return page_zone(zpdesc_page(zpdesc));
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 999b513c7fdff..7f1431f2be98f 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1719,8 +1719,6 @@ 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.
*/
- VM_BUG_ON_PAGE(PageIsolated(page), page);
-
return true;
}

@@ -1739,8 +1737,6 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
unsigned long old_obj, new_obj;
unsigned int obj_idx;

- VM_BUG_ON_PAGE(!zpdesc_is_isolated(zpdesc), zpdesc_page(zpdesc));
-
/* The page is locked, so this pointer must remain valid */
zspage = get_zspage(zpdesc);
pool = zspage->pool;
@@ -1811,7 +1807,6 @@ static int zs_page_migrate(struct page *newpage, struct page *page,

static void zs_page_putback(struct page *page)
{
- VM_BUG_ON_PAGE(!PageIsolated(page), page);
}

static const struct movable_operations zsmalloc_mops = {
--
2.49.0