Re: [PATCH v2 4/9] userfaultfd/shmem: support UFFDIO_CONTINUE for shmem

2021-04-20 Thread Axel Rasmussen
On Fri, Apr 16, 2021 at 4:47 PM Hugh Dickins wrote: > > On Mon, 12 Apr 2021, Axel Rasmussen wrote: > > > With this change, userspace can resolve a minor fault within a > > shmem-backed area with a UFFDIO_CONTINUE ioctl. The semantics for this > > match those for hugetlbfs - we look up the existing

Re: [PATCH v2 4/9] userfaultfd/shmem: support UFFDIO_CONTINUE for shmem

2021-04-16 Thread Hugh Dickins
On Mon, 12 Apr 2021, Axel Rasmussen wrote: > With this change, userspace can resolve a minor fault within a > shmem-backed area with a UFFDIO_CONTINUE ioctl. The semantics for this > match those for hugetlbfs - we look up the existing page in the page > cache, and install PTEs for it. s/PTEs/a PT

[PATCH v2 4/9] userfaultfd/shmem: support UFFDIO_CONTINUE for shmem

2021-04-12 Thread Axel Rasmussen
With this change, userspace can resolve a minor fault within a shmem-backed area with a UFFDIO_CONTINUE ioctl. The semantics for this match those for hugetlbfs - we look up the existing page in the page cache, and install PTEs for it. This commit introduces a new helper: mcopy_atomic_install_ptes.