Re: [PATCH 00/59] MM folio changes for 6.1

[Hugh Dickins <hughd@google.com>]

On Mon, 8 Aug 2022, Matthew Wilcox (Oracle) wrote:

> The first three patches I hope are added into 6.0 before release (and
> the one cc:stable gets backported to 5.19).
> 
> My focus this round has been on shmem.  I believe it is now fully
> converted to folios.  Of course, shmem interacts with a lot of the swap
> cache and other parts of the kernel, so there are patches all over the MM.
> 
> This patch series survives a round of xfstests on tmpfs, which is nice,
> but hardly an exhaustive test.

Yes, xfstests fine on tmpfs (64-bit or 32-bit, huge or not).  Just
one line wrong, in do_swap_page(): I'll respond to 18/59 on that.

I have not looked into the 59 patches at all, but did search through
the total diff, to find the cause for that problem; and having got that
far, thought I'd best look through the remainder too: I found nothing
more that needs to be changed.

Hugh

> 
> Matthew Wilcox (Oracle) (59):
>   mm: Fix VM_BUG_ON in __delete_from_swap_cache()
>   shmem: Update folio if shmem_replace_page() updates the page
>   vmscan: Check folio_test_private(), not folio_get_private()
>   mm/vmscan: Fix a lot of comments
>   mm: Add the first tail page to struct folio
>   mm: Reimplement folio_order() and folio_nr_pages()
>   mm: Add split_folio()
>   mm: Add folio_add_lru_vma()
>   shmem: Convert shmem_writepage() to use a folio throughout
>   shmem: Convert shmem_delete_from_page_cache() to take a folio
>   shmem: Convert shmem_replace_page() to use folios throughout
>   mm/swapfile: Remove page_swapcount()
>   mm/swapfile: Convert try_to_free_swap() to folio_free_swap()
>   mm/swap: Convert __read_swap_cache_async() to use a folio
>   mm/swap: Convert add_to_swap_cache() to take a folio
>   mm/swap: Convert put_swap_page() to put_swap_folio()
>   mm: Convert do_swap_page() to use a folio
>   mm: Convert do_swap_page()'s swapcache variable to a folio
>   memcg: Convert mem_cgroup_swapin_charge_page() to
>     mem_cgroup_swapin_charge_folio()
>   shmem: Convert shmem_mfill_atomic_pte() to use a folio
>   shmem: Convert shmem_replace_page() to shmem_replace_folio()
>   swap: Add swap_cache_get_folio()
>   shmem: Eliminate struct page from shmem_swapin_folio()
>   shmem: Convert shmem_getpage_gfp() to shmem_get_folio_gfp()
>   shmem: Convert shmem_fault() to use shmem_get_folio_gfp()
>   shmem: Convert shmem_read_mapping_page_gfp() to use
>     shmem_get_folio_gfp()
>   shmem: Add shmem_get_folio()
>   shmem: Convert shmem_get_partial_folio() to use shmem_get_folio()
>   shmem: Convert shmem_write_begin() to use shmem_get_folio()
>   shmem: Convert shmem_file_read_iter() to use shmem_get_folio()
>   shmem: Convert shmem_fallocate() to use a folio
>   shmem: Convert shmem_symlink() to use a folio
>   shmem: Convert shmem_get_link() to use a folio
>   khugepaged: Call shmem_get_folio()
>   userfaultfd: Convert mcontinue_atomic_pte() to use a folio
>   shmem: Remove shmem_getpage()
>   swapfile: Convert try_to_unuse() to use a folio
>   swapfile: Convert __try_to_reclaim_swap() to use a folio
>   swapfile: Convert unuse_pte_range() to use a folio
>   mm: Convert do_swap_page() to use swap_cache_get_folio()
>   mm: Remove lookup_swap_cache()
>   swap_state: Convert free_swap_cache() to use a folio
>   swap: Convert swap_writepage() to use a folio
>   mm: Convert do_wp_page() to use a folio
>   huge_memory: Convert do_huge_pmd_wp_page() to use a folio
>   madvise: Convert madvise_free_pte_range() to use a folio
>   uprobes: Use folios more widely in __replace_page()
>   ksm: Use a folio in replace_page()
>   mm: Convert do_swap_page() to use folio_free_swap()
>   memcg: Convert mem_cgroup_swap_full() to take a folio
>   mm: Remove try_to_free_swap()
>   rmap: Convert page_move_anon_rmap() to use a folio
>   migrate: Convert __unmap_and_move() to use folios
>   migrate: Convert unmap_and_move_huge_page() to use folios
>   huge_memory: Convert split_huge_page_to_list() to use a folio
>   huge_memory: Convert unmap_page() to unmap_folio()
>   mm: Convert page_get_anon_vma() to folio_get_anon_vma()
>   rmap: Remove page_unlock_anon_vma_read()
>   uprobes: Use new_folio in __replace_page()
> 
>  include/linux/huge_mm.h    |   5 +
>  include/linux/memcontrol.h |   4 +-
>  include/linux/mm.h         |  12 +-
>  include/linux/mm_types.h   |  30 ++-
>  include/linux/rmap.h       |   7 +-
>  include/linux/shmem_fs.h   |   6 +-
>  include/linux/swap.h       |  35 ++--
>  kernel/events/uprobes.c    |  28 +--
>  mm/folio-compat.c          |   6 +
>  mm/huge_memory.c           |  95 +++++-----
>  mm/khugepaged.c            |   7 +-
>  mm/ksm.c                   |   8 +-
>  mm/madvise.c               |  49 ++---
>  mm/memcontrol.c            |  21 +--
>  mm/memory-failure.c        |   2 +-
>  mm/memory.c                | 151 ++++++++-------
>  mm/migrate.c               | 107 ++++++-----
>  mm/page_io.c               |  21 ++-
>  mm/rmap.c                  |  33 ++--
>  mm/shmem.c                 | 374 ++++++++++++++++++-------------------
>  mm/swap.c                  |  19 +-
>  mm/swap.h                  |  16 +-
>  mm/swap_slots.c            |   2 +-
>  mm/swap_state.c            | 113 +++++------
>  mm/swapfile.c              | 159 ++++++++--------
>  mm/truncate.c              |   2 +-
>  mm/userfaultfd.c           |  14 +-
>  mm/vmscan.c                | 263 +++++++++++++-------------
>  28 files changed, 810 insertions(+), 779 deletions(-)
> 
> -- 
> 2.35.1