On Sun, Oct 04, 2020 at 01:20:31PM +0200, Daniel Vetter wrote: > Yeah I think that works. I tried understanding gup.c code a bit more, > and it looks like FOLL_LONGTERM only works for the pup_fast variant > right now? All others seem to have this comment that it's somehow > incompatible with FAULT_FLAG_ALLOW_RETRY and daxfs. But grepping > around for that didn't show up anything, at least not nearby dax code. > For my understanding of all this, what's the hiccup there? IIRC it needs the VMA and various other flows can't return the vma list becuse they unlock the mmap_sem will running > For plans, I only started this for a bit of my own learning, but I > think I'll respin with the following changes: > - convert exynos and habanalabs to pin_user_pages_fast directly, > instead of going through this frame-vector detour +1 Jason
