This is roughly what we have in -mm and -next, however, includes one additional patch and some minor differences, especially minor fixes in the patch descriptions. v4 is located at: https://github.com/davidhildenbrand/linux/tree/cow_fixes_part_2_v4 Please refer to to v3 cover letter: https://lkml.kernel.org/r/20220329160440.193848-1-david@xxxxxxxxxx v3 -> v4: * Minor changes/fixes in patch descriptions * "mm/rmap: drop "compound" parameter from page_add_new_anon_rmap()" -> Remove VM_BUG_ON_PAGE(PageTransCompound(page), page); * "mm/rmap: fail try_to_migrate() early when setting a PMD migration entry fails" -> Added * "mm: support GUP-triggered unsharing of anonymous pages" -> unlikely(unshare) -> likely(!unshare) in wp_huge_pmd() -> "page_copied && !unshare" -> "(page_copied && !unshare)" * "mm/gup: sanity-check with CONFIG_DEBUG_VM that anonymous pages are exclusive when (un)pinning" -> Use VM_BUG_ON_PAGE() instead of VM_BUG_ON() v2 -> v3: * Note 1: Left the terminology "unshare" in place for now instead of switching to "make anon exclusive". * Note 2: We might have to tackle undoing effects of arch_unmap_one() on sparc, to free some tag memory immediately instead of when tearing down the vma/mm; looks like this needs more care either way, so I'll ignore it for now. * Rebased on top of core MM changes for v5.18-rc1 (most conflicts were due to folio and ZONE_DEVICE migration rework). No severe changes were necessary -- mostly folio conversion and code movement. * Retested on aarch64, ppc64, s390x and x86_64 * "mm/rmap: convert RMAP flags to a proper distinct rmap_t type" -> Missed to convert one instance in restore_exclusive_pte() * "mm/rmap: pass rmap flags to hugepage_add_anon_rmap()" -> Use "!!(flags & RMAP_EXCLUSIVE)" to avoid sparse warnings * "mm/huge_memory: remove outdated VM_WARN_ON_ONCE_PAGE from unmap_page()" -> Added, as we can trigger that now more frequently * "mm: remember exclusively mapped anonymous pages with PG_anon_exclusive" -> Use subpage in VM_BUG_ON_PAGE() in try_to_migrate_one() -> Move comment from folio_migrate_mapping() to folio_migrate_flags() regarding PG_anon_exclusive/PG_mappedtodisk -> s/int rmap_flags/rmap_t rmap_flags/ in remove_migration_pmd() * "mm/gup: sanity-check with CONFIG_DEBUG_VM that anonymous pages are exclusive when (un)pinning" -> Use IS_ENABLED(CONFIG_DEBUG_VM) instead of ifdef v1 -> v2: * Tested on aarch64, ppc64, s390x and x86_64 * "mm/page-flags: reuse PG_mappedtodisk as PG_anon_exclusive for PageAnon() pages" -> Use PG_mappedtodisk instead of PG_slab (thanks Willy!), this simlifies the patch and necessary handling a lot. Add safety BUG_ON's -> Move most documentation to the patch description, to be placed in a proper documentation doc in the future, once everything's in place * ""mm: remember exclusively mapped anonymous pages with PG_anon_exclusive -> Skip check+clearing in page_try_dup_anon_rmap(), otherwise we might trigger a wrong VM_BUG_ON() for KSM pages in ClearPageAnonExclusive() -> In __split_huge_pmd_locked(), call page_try_share_anon_rmap() only for "anon_exclusive", otherwise we might trigger a wrong VM_BUG_ON() -> In __split_huge_page_tail(), drop any remaining PG_anon_exclusive on tail pages, and document why that is fine RFC -> v1: * Rephrased/extended some patch descriptions+comments * Tested on aarch64, ppc64 and x86_64 * "mm/rmap: convert RMAP flags to a proper distinct rmap_t type" -> Added * "mm/rmap: drop "compound" parameter from page_add_new_anon_rmap()" -> Added * "mm: remember exclusively mapped anonymous pages with PG_anon_exclusive" -> Fixed __do_huge_pmd_anonymous_page() to recheck after temporarily dropping the PT lock. -> Use "reuse" label in __do_huge_pmd_anonymous_page() -> Slightly simplify logic in hugetlb_cow() -> In remove_migration_pte(), remove unrelated changes around page_remove_rmap() * "mm: support GUP-triggered unsharing of anonymous pages" -> In handle_pte_fault(), trigger pte_mkdirty() only with FAULT_FLAG_WRITE -> In __handle_mm_fault(), extend comment regarding anonymous PUDs * "mm/gup: trigger FAULT_FLAG_UNSHARE when R/O-pinning a possibly shared anonymous page" -> Added unsharing logic to gup_hugepte() and gup_huge_pud() -> Changed return logic in __follow_hugetlb_must_fault(), making sure that "unshare" is always set * "mm/gup: sanity-check with CONFIG_DEBUG_VM that anonymous pages are exclusive when (un)pinning" -> Slightly simplified sanity_check_pinned_pages() David Hildenbrand (17): mm/rmap: fix missing swap_free() in try_to_unmap() after arch_unmap_one() failed mm/hugetlb: take src_mm->write_protect_seq in copy_hugetlb_page_range() mm/memory: slightly simplify copy_present_pte() mm/rmap: split page_dup_rmap() into page_dup_file_rmap() and page_try_dup_anon_rmap() mm/rmap: convert RMAP flags to a proper distinct rmap_t type mm/rmap: remove do_page_add_anon_rmap() mm/rmap: pass rmap flags to hugepage_add_anon_rmap() mm/rmap: drop "compound" parameter from page_add_new_anon_rmap() mm/rmap: use page_move_anon_rmap() when reusing a mapped PageAnon() page exclusively mm/huge_memory: remove outdated VM_WARN_ON_ONCE_PAGE from unmap_page() mm/page-flags: reuse PG_mappedtodisk as PG_anon_exclusive for PageAnon() pages mm: remember exclusively mapped anonymous pages with PG_anon_exclusive mm/rmap: fail try_to_migrate() early when setting a PMD migration entry fails mm/gup: disallow follow_page(FOLL_PIN) mm: support GUP-triggered unsharing of anonymous pages mm/gup: trigger FAULT_FLAG_UNSHARE when R/O-pinning a possibly shared anonymous page mm/gup: sanity-check with CONFIG_DEBUG_VM that anonymous pages are exclusive when (un)pinning include/linux/mm.h | 46 +++++++- include/linux/mm_types.h | 8 ++ include/linux/page-flags.h | 39 ++++++- include/linux/rmap.h | 118 +++++++++++++++++-- include/linux/swap.h | 15 ++- include/linux/swapops.h | 29 ++++- kernel/events/uprobes.c | 2 +- mm/gup.c | 106 ++++++++++++++++- mm/huge_memory.c | 133 ++++++++++++++++----- mm/hugetlb.c | 135 ++++++++++++++------- mm/khugepaged.c | 2 +- mm/ksm.c | 15 ++- mm/memory.c | 234 +++++++++++++++++++++++-------------- mm/memremap.c | 9 ++ mm/migrate.c | 18 ++- mm/migrate_device.c | 23 +++- mm/mprotect.c | 8 +- mm/rmap.c | 105 ++++++++++++----- mm/swapfile.c | 8 +- mm/userfaultfd.c | 2 +- tools/vm/page-types.c | 8 +- 21 files changed, 836 insertions(+), 227 deletions(-) base-commit: af2d861d4cd2a4da5137f795ee3509e6f944a25b -- 2.35.1
