Re: [PATCH v1 06/29] mm/zsmalloc: make PageZsmalloc() sticky until the page is freed

David Hildenbrand
2025-07-01T08:27:31Z

On 30.06.25 18:03, Lorenzo Stoakes wrote:
> On Mon, Jun 30, 2025 at 02:59:47PM +0200, David Hildenbrand wrote:
>> Let the page freeing code handle clearing the page type.
>>
>> 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>
>
> On basis of sanity of UINT_MAX thing:
>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
>
>> ---
>> mm/zpdesc.h | 5 -----
>> mm/zsmalloc.c | 3 +--
>> 2 files changed, 1 insertion(+), 7 deletions(-)
>>
>> diff --git a/mm/zpdesc.h b/mm/zpdesc.h
>> index 5cb7e3de43952..5763f36039736 100644
>> --- 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 7f1431f2be98f..f98747aed4330 100644
>> --- a/mm/zsmalloc.c
>> +++ b/mm/zsmalloc.c
>> @@ -880,7 +880,7 @@ 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 +1055,6 @@ static struct zspage *alloc_zspage(struct zs_pool *pool,
>> if (!zpdesc) {
>> while (--i >= 0) {
>> zpdesc_dec_zone_page_state(zpdescs[i]);
>
> Maybe for consistency put a
>
> /* PageZsmalloc is sticky until the page is freed to the buddy. */
>

I'll add that inside free_zpdesc(), before the __free_page().

Thanks!

--
Cheers,

David / dhildenb