Re: [PATCH 2/2] xen: don't use page->lru for ZONE_DEVICE memory

[Jason Andryuk]

On Mon, Dec 7, 2020 at 8:30 AM Juergen Gross <jgross@xxxxxxxx> wrote:
>
> Commit 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated
> memory") introduced usage of ZONE_DEVICE memory for foreign memory
> mappings.
>
> Unfortunately this collides with using page->lru for Xen backend
> private page caches.
>
> Fix that by using page->zone_device_data instead.
>
> Fixes: 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory")
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Would it make sense to add BUG_ON(is_zone_device_page(page)) and the
opposite as appropriate to cache_enq?  Either way:
Reviewed-by: Jason Andryuk <jandryuk@xxxxxxxxx>