On 2016/7/18 13:51, 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 > __GFP_HIGHMEM and __GFP_USER. >
Hi Joonsoo, So the original code "gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;" is not correct? > And, zram's memory isn't GFP_HIGHUSER_MOVABLE but has __GFP_MOVABLE. > Can we distinguish __GFP_MOVABLE or GFP_HIGHUSER_MOVABLE when doing mem-hotplug? Thanks, Xishi Qiu > Thanks. > > > . >
