[based on akpm/mm-unstable, latest ca95745c20ad, of Jan 7th 2025] v2: - Rebase to latest mm-unstable - Added R-b and T-b for Ackerley on patch 1 (Ackerley: I was conservative on the tags here to only attach them in patch 1, even though it seems you mentioned you agree/tested with the whole series. Please feel free to provide your tag again on the cover letter if you want, thanks) This is a follow up on Ackerley's series here as replacement: https://lore.kernel.org/r/cover.1728684491.git.ackerleytng@xxxxxxxxxx The goal of this series is to cleanup hugetlb resv accounting, especially during folio allocation, to decouple a few things: - Hugetlb folios v.s. Hugetlbfs: IOW, the hope is in the future hugetlb folios can be allocated completely without hugetlbfs. - Decouple VMA v.s. hugetlb folio allocations: allocating a hugetlb folio should not always require a hugetlbfs VMA. For example, either it got allocated from the inode level (see hugetlbfs_fallocate() where it used a pesudo VMA for allocation), or it can be allocated by other kernel subsystems. It paves way for other users to allocate hugetlb folios out of either system reservations, or subpools (instead of hugetlbfs, as a file system). For longer term, this prepares hugetlb as a separate concept versus hugetlbfs, so that hugetlb folios can be allocated by not only hugetlbfs and other things. Tests I've done: - I had a reproducer in patch 1 for the bug I found, this will start to work after patch 1 or the whole set applied. - Hugetlb regression tests (on x86_64 2MBs), includes: - All vmtests on hugetlbfs - libhugetlbfs test suite (which may fail some tests, but no new failures will be introduced by this series, so all such failures happen before this series so shouldn't be relevant). Comments welcomed, thanks. Peter Xu (7): mm/hugetlb: Fix avoid_reserve to allow taking folio from subpool mm/hugetlb: Stop using avoid_reserve flag in fork() mm/hugetlb: Rename avoid_reserve to cow_from_owner mm/hugetlb: Clean up map/global resv accounting when allocate mm/hugetlb: Simplify vma_has_reserves() mm/hugetlb: Drop vma_has_reserves() mm/hugetlb: Unify restore reserve accounting for new allocations fs/hugetlbfs/inode.c | 2 +- include/linux/hugetlb.h | 4 +- mm/hugetlb.c | 237 ++++++++++++++++++---------------------- 3 files changed, 107 insertions(+), 136 deletions(-) -- 2.47.0
