Re: [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO)

From: Dave Hansen
Date: Mon Nov 13 2017 - 17:20:29 EST


On 11/09/2017 05:09 PM, Tycho Andersen wrote:
> which I guess is from the additional flags in grow_dev_page() somewhere down
> the stack. Anyway... it seems this is a kernel allocation that's using
> MIGRATE_MOVABLE, so perhaps we need some more fine tuned heuristic than just
> all MOVABLE allocations are un-mapped via xpfo, and all the others are mapped.
>
> Do you have any ideas?

It still has to do a kmap() or kmap_atomic() to be able to access it. I
thought you hooked into that. Why isn't that path getting hit for these?