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

Joonsoo Kim
2016-07-18T05:47:48Z

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
__GFP_HIGHMEM and __GFP_USER.

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

Thanks.