mm/zsmalloc: make PageZsmalloc() sticky until the page is freed

Let the page freeing code handle clearing the page type.  Being able to
identify balloon pages until actually freed is a requirement for upcoming
movable_ops migration changes.

Link: https://lkml.kernel.org/r/20250704102524.326966-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pé rez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/zpdesc.h b/mm/zpdesc.h
index 5cb7e3de43952c2373c4477c823da43979402aa5..5763f3603973604660280372d3cc2eabc04ef681 100644 (file)
--- a/mm/zpdesc.h
+++ b/mm/zpdesc.h
@@ -163,11 +163,6 @@ static inline void __zpdesc_set_zsmalloc(struct zpdesc *zpdesc)
        __SetPageZsmalloc(zpdesc_page(zpdesc));
 }
 
-static inline void __zpdesc_clear_zsmalloc(struct zpdesc *zpdesc)
-{
-       __ClearPageZsmalloc(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 7f1431f2be98fa9256b32ccafede86b28b56c5da..626f09fb271384d4bf728f78c405c54a2b2a8d3f 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -244,6 +244,7 @@ static inline void free_zpdesc(struct zpdesc *zpdesc)
 {
        struct page *page = zpdesc_page(zpdesc);
 
+       /* PageZsmalloc is sticky until the page is freed to the buddy. */
        __free_page(page);
 }
 
@@ -880,7 +881,7 @@ static void reset_zpdesc(struct zpdesc *zpdesc)
        ClearPagePrivate(page);
        zpdesc->zspage = NULL;
        zpdesc->next = NULL;
-       __ClearPageZsmalloc(page);
+       /* PageZsmalloc is sticky until the page is freed to the buddy. */
 }
 
 static int trylock_zspage(struct zspage *zspage)
@@ -1055,7 +1056,6 @@ static struct zspage *alloc_zspage(struct zs_pool *pool,
                if (!zpdesc) {
                        while (--i >= 0) {
                                zpdesc_dec_zone_page_state(zpdescs[i]);
-                               __zpdesc_clear_zsmalloc(zpdescs[i]);
                                free_zpdesc(zpdescs[i]);
                        }
                        cache_free_zspage(pool, zspage);