Messages in this thread | | | Subject | Re: [PATCH v4 09/10] userfaultfd: update documentation to describe minor fault handling | From | Randy Dunlap <> | Date | Thu, 4 Feb 2021 11:57:36 -0800 |
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Hi Axel-
one typo found:
On 2/4/21 10:34 AM, Axel Rasmussen wrote: > Reword / reorganize things a little bit into "lists", so new features / > modes / ioctls can sort of just be appended.
Good plan.
> > Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> > --- > Documentation/admin-guide/mm/userfaultfd.rst | 107 ++++++++++++------- > 1 file changed, 66 insertions(+), 41 deletions(-) > > diff --git a/Documentation/admin-guide/mm/userfaultfd.rst b/Documentation/admin-guide/mm/userfaultfd.rst > index 65eefa66c0ba..cfd3daf59d0e 100644 > --- a/Documentation/admin-guide/mm/userfaultfd.rst > +++ b/Documentation/admin-guide/mm/userfaultfd.rst
[snip]
> - > -Once the ``userfaultfd`` has been enabled the ``UFFDIO_REGISTER`` ioctl should > -be invoked (if present in the returned ``uffdio_api.ioctls`` bitmask) to > -register a memory range in the ``userfaultfd`` by setting the > +events, except page fault notifications, may be generated: > + > +- The ``UFFD_FEATURE_EVENT_*`` flags indicate that various other events > + other than page faults are supported. These events are described in more > + detail below in the `Non-cooperative userfaultfd`_ section. > + > +- ``UFFD_FEATURE_MISSING_HUGETLBFS`` and ``UFFD_FEATURE_MISSING_SHMEM`` > + indicate that the kernel supports ``UFFDIO_REGISTER_MODE_MISSING`` > + registrations for hugetlbfs and shared memory (covering all shmem APIs, > + i.e. tmpfs, ``IPCSHM``, ``/dev/zero``, ``MAP_SHARED``, ``memfd_create``, > + etc) virtual memory areas, respectively. > + > +- ``UFFD_FEATURE_MINOR_HUGETLBFS`` indicates that the kernel supports > + ``UFFDIO_REGISTER_MODE_MINOR`` registration for hugetlbfs virtual memory > + areas. > + > +The userland application should set the feature flags it intends to use
(ah, userspace has moved to userland temporarily. :)
> +when envoking the ``UFFDIO_API`` ioctl, to request that those features be
invoking
> +enabled if supported.
thanks. -- ~Randy
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