On 7/8/24 2:33 PM, alexs@xxxxxxxxxx wrote: > From: Alex Shi (Tencent) <alexs@xxxxxxxxxx> > > According to Metthew's plan, the page descriptor will be replace by a 8 > bytes mem_desc on destination purpose. > https://lore.kernel.org/lkml/YvV1KTyzZ+Jrtj9x@xxxxxxxxxxxxxxxxxxxx/ > > Here is a implement on zsmalloc to replace page descriptor by 'zpdesc', > which is still overlay on struct page now. but it's a step move forward > above destination. > > To name the struct zpdesc instead of zsdesc, since there are still 3 > zpools under zswap: zbud, z3fold, zsmalloc for now(z3fold maybe removed > soon), and we could easyly extend it to other zswap.zpool in needs. > > For all zswap.zpools, they are all using single page since often used > under memory pressure. So the conversion via folio series helper is > better than page's for compound_head check saving. > > For now, all zpools are using some page struct members, like page.flags > for PG_private/PG_locked. and list_head lru, page.mapping for page migration. > > This patachset does not increase the descriptor size nor introduce any > functional changes, and could save about 122Kbytes zsmalloc.o size. > > Thanks > Alex > Any comments for this patchset? Thanks Alex > --- > v3->v2: > - Fix LKP reported build issue > - Update the Usage of struct zpdesc fields. > - Rebase onto latest mm-unstable commit 2073cda629a4 > > v1->v2: > - Take Yosry and Yoo's suggestion to add more members in zpdesc, > - Rebase on latest mm-unstable commit 31334cf98dbd > --- > > Alex Shi (Tencent) (9): > mm/zsmalloc: add zpdesc memory descriptor for zswap.zpool > mm/zsmalloc: use zpdesc in trylock_zspage/lock_zspage > mm/zsmalloc: convert create_page_chain() and its users to use zpdesc > mm/zsmalloc: rename reset_page to reset_zpdesc and use zpdesc in it > mm/zsmalloc: convert SetZsPageMovable and remove unused funcs > mm/zsmalloc: convert get/set_first_obj_offset() to take zpdesc > mm/zsmalloc: introduce __zpdesc_clear_movable > mm/zsmalloc: introduce __zpdesc_clear_zsmalloc > mm/zsmalloc: introduce __zpdesc_set_zsmalloc() > > Hyeonggon Yoo (11): > mm/zsmalloc: convert __zs_map_object/__zs_unmap_object to use zpdesc > mm/zsmalloc: add and use pfn/zpdesc seeking funcs > mm/zsmalloc: convert obj_malloc() to use zpdesc > mm/zsmalloc: convert obj_allocated() and related helpers to use zpdesc > mm/zsmalloc: convert init_zspage() to use zpdesc > mm/zsmalloc: convert obj_to_page() and zs_free() to use zpdesc > mm/zsmalloc: add zpdesc_is_isolated/zpdesc_zone helper for > zs_page_migrate > mm/zsmalloc: convert __free_zspage() to use zdsesc > mm/zsmalloc: convert location_to_obj() to take zpdesc > mm/zsmalloc: convert migrate_zspage() to use zpdesc > mm/zsmalloc: convert get_zspage() to take zpdesc > > mm/zpdesc.h | 146 ++++++++++++++++ > mm/zsmalloc.c | 460 +++++++++++++++++++++++++++----------------------- > 2 files changed, 398 insertions(+), 208 deletions(-) > create mode 100644 mm/zpdesc.h >
