Re: [PATCH 1/2] mem-hotplug: use GFP_HIGHUSER_MOVABLE in, alloc_migrate_target()

From: Vlastimil Babka
Date: Mon Jul 18 2016 - 03:45:29 EST

On 07/18/2016 07:51 AM, Joonsoo Kim wrote:
On Fri, Jul 15, 2016 at 10:47:06AM +0800, Xishi Qiu wrote:
alloc_migrate_target() is called from migrate_pages(), and the page
is always from user space, so we can add __GFP_HIGHMEM directly.

No, all migratable pages are not from user space. For example,
blockdev file cache has __GFP_MOVABLE and migratable but it has no

And, zram's memory isn't GFP_HIGHUSER_MOVABLE but has __GFP_MOVABLE.

Right, and there's also Minchan's series for arbitrary driver page migration...