Messages in this thread | | | Date | Wed, 4 Nov 2020 10:00:23 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v5 05/15] mm/frame-vector: Use FOLL_LONGTERM |
| |
On Sun, Nov 01, 2020 at 11:50:39PM +0100, Daniel Vetter wrote:
> It's not device drivers, but everyone else. At least my understanding > is that VM_IO | VM_PFNMAP means "even if it happens to be backed by a > struct page, do not treat it like normal memory". And gup/pup_fast > happily break that. I tried to chase the history of that test, didn't > turn up anything I understood much:
VM_IO isn't suppose do thave struct pages, so how can gup_fast return them?
I thought some magic in the PTE flags excluded this?
Jason
| |