Re: [PATCH v5 03/10] userfaultfd/shmem: support minor fault registration for shmem

[Hugh Dickins]

On Tue, 27 Apr 2021, Axel Rasmussen wrote:

> This patch allows shmem-backed VMAs to be registered for minor faults.
> Minor faults are appropriately relayed to userspace in the fault path,
> for VMAs with the relevant flag.
> 
> This commit doesn't hook up the UFFDIO_CONTINUE ioctl for shmem-backed
> minor faults, though, so userspace doesn't yet have a way to resolve
> such faults.
> 
> Because of this, we also don't yet advertise this as a supported
> feature. That will be done in a separate commit when the feature is
> fully implemented.
> 
> Acked-by: Peter Xu <peterx@xxxxxxxxxx>
> Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>

Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>

> ---
>  fs/userfaultfd.c |  3 +--
>  mm/memory.c      |  8 +++++---
>  mm/shmem.c       | 12 +++++++++++-
>  3 files changed, 17 insertions(+), 6 deletions(-)