On Tue, Dec 17, 2024 at 12:04:42AM +0900, Hyeonggon Yoo wrote:
> From: Alex Shi <alexs@xxxxxxxxxx>
>
> zpdesc.zspage matches with page.private, zpdesc.next matches with
> page.index. They will be reset in reset_page() which is called prior to
> free base pages of a zspage.
>
> Since the fields that need to be initialized are independent of the
> order in struct zpdesc, Keep it to use struct page to ensure robustness
> against potential rearrangements of struct zpdesc fields in the future.
>
> [42.hyeyoo: keep reset_zpdesc() to use struct page fields]
Ummm ... why did you make this change? Now page->index still has a user
in zsmalloc ;-(
> Signed-off-by: Alex Shi <alexs@xxxxxxxxxx>
> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
> ---
> mm/zsmalloc.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 432e78e61d2e..dded6d1f3b7a 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -843,8 +843,10 @@ static inline bool obj_allocated(struct zpdesc *zpdesc, void *obj,
> return true;
> }
>
> -static void reset_page(struct page *page)
> +static void reset_zpdesc(struct zpdesc *zpdesc)
> {
> + struct page *page = zpdesc_page(zpdesc);
> +
> __ClearPageMovable(page);
> ClearPagePrivate(page);
> set_page_private(page, 0);
> @@ -887,7 +889,7 @@ static void __free_zspage(struct zs_pool *pool, struct size_class *class,
> do {
> VM_BUG_ON_PAGE(!PageLocked(page), page);
> next = get_next_page(page);
> - reset_page(page);
> + reset_zpdesc(page_zpdesc(page));
> unlock_page(page);
> dec_zone_page_state(page, NR_ZSPAGES);
> put_page(page);
> @@ -1865,7 +1867,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
> zpdesc_inc_zone_page_state(newzpdesc);
> }
>
> - reset_page(page);
> + reset_zpdesc(zpdesc);
> zpdesc_put(zpdesc);
>
> return MIGRATEPAGE_SUCCESS;
> --
> 2.43.5
>
