Hi Andrew, This patchset missed the merge window, but I've tried and found that it still applies cleanly to today's mm-unstable. Would you like me to resend it or just proceed with using this v4 version? Thanks Barry On Thu, May 9, 2024 at 10:41 AM Barry Song <21cnbao@xxxxxxxxx> wrote: > > From: Barry Song <v-songbaohua@xxxxxxxx> > > This patch is extracted from the large folio swapin series[1], primarily addressing > the handling of scenarios involving large folios in the swap cache. Currently, it is > particularly focused on addressing the refaulting of mTHP, which is still undergoing > reclamation. This approach aims to streamline code review and expedite the integration > of this segment into the MM tree. > > It relies on Ryan's swap-out series[2], leveraging the helper function > swap_pte_batch() introduced by that series. > > Presently, do_swap_page only encounters a large folio in the swap > cache before the large folio is released by vmscan. However, the code > should remain equally useful once we support large folio swap-in via > swapin_readahead(). This approach can effectively reduce page faults > and eliminate most redundant checks and early exits for MTE restoration > in recent MTE patchset[3]. > > The large folio swap-in for SWP_SYNCHRONOUS_IO and swapin_readahead() > will be split into separate patch sets and sent at a later time. > > -v4: > - collect acked-by/reviewed-by of Ryan, "Huang, Ying", Chris, David and > Khalid, many thanks! > - Simplify reuse code in do_swap_page() by checking refcount==1, per > David; > - Initialize large folio-related variables later in do_swap_page(), per > Ryan; > - define swap_free() as swap_free_nr(1) per Ying and Ryan. > > -v3: > - optimize swap_free_nr using bitmap with single one "long"; "Huang, Ying" > - drop swap_free() as suggested by "Huang, Ying", now hibernation can get > batched; > - lots of cleanup in do_swap_page() as commented by Ryan Roberts and "Huang, > Ying"; > - handle arch_do_swap_page() with nr pages though the only platform which > needs it, sparc, doesn't support THP_SWAPOUT as suggested by "Huang, > Ying"; > - introduce pte_move_swp_offset() as suggested by "Huang, Ying"; > - drop the "any_shared" of checking swap entries with respect to David's > comment; > - drop the counter of swapin_refault and keep it for debug purpose per > Ying > - collect reviewed-by tags > Link: > https://lore.kernel.org/linux-mm/20240503005023.174597-1-21cnbao@xxxxxxxxx/ > > -v2: > - rebase on top of mm-unstable in which Ryan's swap_pte_batch() has changed > a lot. > - remove folio_add_new_anon_rmap() for !folio_test_anon() > as currently large folios are always anon(refault). > - add mTHP swpin refault counters > Link: > https://lore.kernel.org/linux-mm/20240409082631.187483-1-21cnbao@xxxxxxxxx/ > > -v1: > Link: https://lore.kernel.org/linux-mm/20240402073237.240995-1-21cnbao@xxxxxxxxx/ > > Differences with the original large folios swap-in series > - collect r-o-b, acked; > - rename swap_nr_free to swap_free_nr, according to Ryan; > - limit the maximum kernel stack usage for swap_free_nr, Ryan; > - add output argument in swap_pte_batch to expose if all entries are > exclusive > - many clean refinements, handle the corner case folio's virtual addr > might not be naturally aligned > > [1] https://lore.kernel.org/linux-mm/20240304081348.197341-1-21cnbao@xxxxxxxxx/ > [2] https://lore.kernel.org/linux-mm/20240408183946.2991168-1-ryan.roberts@xxxxxxx/ > [3] https://lore.kernel.org/linux-mm/20240322114136.61386-1-21cnbao@xxxxxxxxx/ > > Barry Song (3): > mm: remove the implementation of swap_free() and always use > swap_free_nr() > mm: introduce pte_move_swp_offset() helper which can move offset > bidirectionally > mm: introduce arch_do_swap_page_nr() which allows restore metadata for > nr pages > > Chuanhua Han (3): > mm: swap: introduce swap_free_nr() for batched swap_free() > mm: swap: make should_try_to_free_swap() support large-folio > mm: swap: entirely map large folios found in swapcache > > include/linux/pgtable.h | 26 +++++++++++++----- > include/linux/swap.h | 9 +++++-- > kernel/power/swap.c | 5 ++-- > mm/internal.h | 25 ++++++++++++++--- > mm/memory.c | 60 +++++++++++++++++++++++++++++++++-------- > mm/swapfile.c | 48 +++++++++++++++++++++++++++++---- > 6 files changed, 142 insertions(+), 31 deletions(-) > > -- > 2.34.1 >
