diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/mm/pagemap.rst | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst index c57e61b5d8aa..ffa690a171c8 100644 --- a/Documentation/admin-guide/mm/pagemap.rst +++ b/Documentation/admin-guide/mm/pagemap.rst @@ -19,8 +19,11 @@ There are four components to pagemap: * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) * Bit 56 page exclusively mapped (since 4.2) - * Bit 57 pte is uffd-wp write-protected (since 5.13) (see - Documentation/admin-guide/mm/userfaultfd.rst) + * Bit 57 pte is tracked by userfaultfd (since 5.13) — in a + ``VM_UFFD_WP`` VMA this indicates a write-protected PTE; in a + ``VM_UFFD_RWP`` VMA it indicates an RWP-protected PTE. WP and + RWP are mutually exclusive per VMA, so the meaning is + unambiguous. See Documentation/admin-guide/mm/userfaultfd.rst. * Bit 58 pte is a guard region (since 6.15) (see madvise (2) man page) * Bits 59-60 zero * Bit 61 page is file-page or shared-anon (since 3.5) @@ -244,7 +247,8 @@ in this IOCTL: Following flags about pages are currently supported: - ``PAGE_IS_WPALLOWED`` - Page has async-write-protection enabled -- ``PAGE_IS_WRITTEN`` - Page has been written to from the time it was write protected +- ``PAGE_IS_WRITTEN`` - Page in a ``UFFDIO_REGISTER_MODE_WP`` VMA has been + written to since it was write-protected. Only reported inside such VMAs. - ``PAGE_IS_FILE`` - Page is file backed - ``PAGE_IS_PRESENT`` - Page is present in the memory - ``PAGE_IS_SWAPPED`` - Page is in swapped @@ -252,6 +256,9 @@ Following flags about pages are currently supported: - ``PAGE_IS_HUGE`` - Page is PMD-mapped THP or Hugetlb backed - ``PAGE_IS_SOFT_DIRTY`` - Page is soft-dirty - ``PAGE_IS_GUARD`` - Page is a part of a guard region +- ``PAGE_IS_ACCESSED`` - Page in a ``UFFDIO_REGISTER_MODE_RWP`` VMA has been + accessed since RWP was applied. Only reported inside such VMAs. See + Documentation/admin-guide/mm/userfaultfd.rst for the RWP workflow. The ``struct pm_scan_arg`` is used as the argument of the IOCTL. |