This patchset is in RFC stage. It's mostly because it is only yet tested on x86_64 in a VM. Not even compile tested on PPC or any other archs, it means at least the hugepd patch (patch 11) is mostly untested, or even not compile tested. Before doing that, I'd like to collect any information from high level. If anyone would like to provide any testing either over hugepd or CONT_PMD / CONT_PTE on ARM (before I reach there..), or RISCV over 64K Svnapot, that'll be very much appreciated. I'm copying PPC, ARM, RISCV list for that. It can be as simple as "./run_vmtests.sh -t gup_test -a" for now, making sure hugetlb pages can be allocated along the way; the non-hugetlb gup tests will guaranteed to be covered more or less, I suppose. In summary, this is a continuous work for previous series: https://lore.kernel.org/all/20230628215310.73782-1-peterx@xxxxxxxxxx And this more or less is my current take to move one more small step towards merging hugetlb code into generic mm code, as much as we can. That part-1 series dropped follow_hugetlb_page(). The plan of this one is to further drops hugetlb_follow_page_mask(). The hugetlb GUP will use the same code path for generic mm after whole set applied. It means the generic code will need to at least understand hugepd, and that's already done like so in fast-gup. Fortunately it seems that's the only major thing I need to teach GUP to share the common path for now besides normal huge PxD entries. Non-gup can be more challenging, but that's a question for later. Patch layout: ============= Patch 1-4: Preparation works, mm generic part Patch 5-6: Bugfixes; I think patch 5 if verified can be merged earlier Patch 7-11: Preparation works, gup part Patch 12: Drop hugetlb_follow_page_mask() More information can be found in the commit messages of each patch. Any comment will be welcomed. Thanks. Peter Xu (12): mm/hugetlb: Export hugetlbfs_pagecache_present() mm: Provide generic pmd_thp_or_huge() mm: Export HPAGE_PXD_* macros even if !THP mm: Introduce vma_pgtable_walk_{begin|end}() mm/gup: Fix follow_devmap_p[mu]d() to return even if NULL mm/gup: Drop folio_fast_pin_allowed() in hugepd processing mm/gup: Refactor record_subpages() to find 1st small page mm/gup: Handle hugetlb for no_page_table() mm/gup: Handle huge pud for follow_pud_mask() mm/gup: Handle huge pmd for follow_pmd_mask() mm/gup: Handle hugepd for follow_page() mm/gup: Merge hugetlb into generic mm code include/linux/huge_mm.h | 34 +++---- include/linux/hugetlb.h | 10 +- include/linux/mm.h | 3 + include/linux/pgtable.h | 4 + mm/gup.c | 197 +++++++++++++++++++++++++--------------- mm/huge_memory.c | 117 +++++++++++++----------- mm/hugetlb.c | 75 +-------------- mm/internal.h | 6 +- mm/memory.c | 12 +++ 9 files changed, 233 insertions(+), 225 deletions(-) -- 2.41.0
