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.