On 6/25/24 5:46 AM, Yosry Ahmed wrote: > On Thu, Jun 20, 2024 at 10:42 PM <alexs@xxxxxxxxxx> wrote: >> >> From: Alex Shi <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 z3fold 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 z3fold_desc, since there are 3 zpool >> usages under zswap, zbud, z3fold, zsmalloc. It looks like we may extend the >> zpdesc to zbud and zsmalloc, combined their usage into one. > > Please do not focus your development efforts on z3fold. We really want > to deprecate/remove it, as well as zbud eventually. See [1]. > > For zsmalloc, there is already an ongoing effort to split zsdesc from > struct page [2]. > > [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndqF+3+_Vg@xxxxxxxxxxxxxx/ Hi Yosry, Thanks a lot for the info and comments! It's my stupid w/o checking the email list before work on it. Anyway don't know if z3fold would be removed, jut left this tested patchset here if someone need it. > > [2]https://lore.kernel.org/lkml/20230713042037.980211-1-42.hyeyoo@xxxxxxxxx/ David had pointed out this to me few weeks ago too. This patchset hasn't updated nearly a year. If Yoo don't object I'd like to pick up from his left and update it to latest zsmalloc.c. Thanks Alex > >> >> For zpdesc(page), z3fold just uses the 5th member zppage_flag, which >> match with page.private. Potentially uses the first member flags for >> headless PG_locked, list_head lru and page.mapping|PAGE_MAPPING_MOVABLE >> for page migration. >> >> This patachset could save 26Kbyetes z3fold.o size, basely saving come >> from the page to folio conversion. >> >> Thanks a lot! >> Alex >> >> Alex Shi (15): >> mm/z3fold: add zpdesc struct and helper and use them in >> z3fold_page_isolate >> mm/z3fold: use zpdesc in z3fold_page_migrate >> mm/z3fold: use zpdesc in z3fold_page_putback >> mm/z3fold: use zpdesc in get/put_z3fold_header funcs >> mm/z3fold: use zpdesc in init_z3fold_page >> mm/z3fold: use zpdesc in free_z3fold_page >> mm/z3fold: convert page to zpdesc in __release_z3fold_page >> mm/z3fold: use zpdesc free_pages_work >> mm/z3fold: use zpdesc in z3fold_compact_page and do_compact_page >> mm/z3fold: use zpdesc in __z3fold_alloc >> mm/z3fold: use zpdesc in z3fold_alloc >> mm/z3fold: use zpdesc in free_z3fold_page and z3fold_free >> mm/z3fold: use zpdesc in z3fold_map/z3fold_unmap >> mm/z3fold: introduce __zpdesc_set_movable >> mm/z3fold: introduce __zpdesc_clear_movable >> >> mm/z3fold.c | 190 +++++++++++++++++++++++++++------------------------- >> mm/zpdesc.h | 87 ++++++++++++++++++++++++ >> 2 files changed, 184 insertions(+), 93 deletions(-) >> create mode 100644 mm/zpdesc.h >> >> -- >> 2.43.0 >> >>
