Hi Gerd, On 14 March 2018 at 08:03, Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: >> Either mlock account (because it's mlocked defacto), and get_user_pages >> won't do that for you. >> >> Or you write the full-blown userptr implementation, including mmu_notifier >> support (see i915 or amdgpu), but that also requires Christian Königs >> latest ->invalidate_mapping RFC for dma-buf (since atm exporting userptr >> buffers is a no-go). > > I guess I'll look at mlock accounting for starters then. Easier for > now, and leaves the door open to switch to userptr later as this should > be transparent to userspace. Out of interest, do you have usecases for full userptr support? Maybe another way would be to allow creation of dmabufs from memfds. Cheers, Daniel