5 Oct
2020
5 Oct
'20
5:35 p.m.
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