The patch titled Subject: mm: allow can_split_folio() to be called when THP are disabled has been added to the -mm mm-unstable branch. Its filename is mm-allow-can_split_folio-to-be-called-when-thp-are-disabled.patch This patch should soon appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm: allow can_split_folio() to be called when THP are disabled The call to can_split_folio() in vmscan is currently guarded by a test of PageTransHuge() so the BUILD_BUG() is eliminated if THP are disabled. The next patch replaces that test with folio_test_large() which may be true, even when THP are disabled. However, if THP are disabled, we cannot split, so an unconditional return of false is appropriate. Link: https://lkml.kernel.org/r/20220504182857.4013401-15-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/huge_mm.h | 1 - 1 file changed, 1 deletion(-) --- a/include/linux/huge_mm.h~mm-allow-can_split_folio-to-be-called-when-thp-are-disabled +++ a/include/linux/huge_mm.h @@ -348,7 +348,6 @@ static inline void prep_transhuge_page(s static inline bool can_split_folio(struct folio *folio, int *pextra_pins) { - BUILD_BUG(); return false; } static inline int _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are shmem-convert-shmem_alloc_hugepage-to-use-vma_alloc_folio.patch mm-huge_memory-convert-do_huge_pmd_anonymous_page-to-use-vma_alloc_folio.patch alpha-fix-alloc_zeroed_user_highpage_movable.patch mm-remove-alloc_pages_vma.patch vmscan-use-folio_mapped-in-shrink_page_list.patch vmscan-convert-the-writeback-handling-in-shrink_page_list-to-folios.patch swap-turn-get_swap_page-into-folio_alloc_swap.patch swap-convert-add_to_swap-to-take-a-folio.patch vmscan-convert-dirty-page-handling-to-folios.patch vmscan-convert-page-buffer-handling-to-use-folios.patch vmscan-convert-lazy-freeing-to-folios.patch vmscan-move-initialisation-of-mapping-down.patch vmscan-convert-the-activate_locked-portion-of-shrink_page_list-to-folios.patch mm-allow-can_split_folio-to-be-called-when-thp-are-disabled.patch vmscan-remove-remaining-uses-of-page-in-shrink_page_list.patch mm-shmem-use-a-folio-in-shmem_unused_huge_shrink.patch mm-swap-add-folio_throttle_swaprate.patch mm-shmem-convert-shmem_add_to_page_cache-to-take-a-folio.patch mm-shmem-turn-shmem_should_replace_page-into-shmem_should_replace_folio.patch mm-shmem-add-shmem_alloc_folio.patch mm-shmem-convert-shmem_alloc_and_acct_page-to-use-a-folio.patch mm-shmem-convert-shmem_getpage_gfp-to-use-a-folio.patch mm-shmem-convert-shmem_swapin_page-to-shmem_swapin_folio.patch mm-add-folio_mapping_flags.patch mm-add-folio_test_movable.patch mm-migrate-convert-move_to_new_page-into-move_to_new_folio.patch