[CC for real] On Thu 27-07-17 10:12:36, Michal Hocko wrote: > On Thu 27-07-17 13:30:31, Aneesh Kumar K.V wrote: > > > > > > On 07/27/2017 12:58 PM, Michal Hocko wrote: > > >On Thu 27-07-17 07:52:08, Aneesh Kumar K.V wrote: > > >>Michal Hocko <mhocko@xxxxxxxxxx> writes: > > >> > > >>>Hi, > > >>>I've just noticed that alloc_gigantic_page ignores movability of the > > >>>gigantic page and it uses any existing zone. Considering that > > >>>hugepage_migration_supported only supports 2MB and pgd level hugepages > > >>>then 1GB pages are not migratable and as such allocating them from a > > >>>movable zone will break the basic expectation of this zone. Standard > > >>>hugetlb allocations try to avoid that by using htlb_alloc_mask and I > > >>>believe we should do the same for gigantic pages as well. > > >>> > > >>>I suspect this behavior is not intentional. What do you think about the > > >>>following untested patch? > > >> > > >> > > >>I also noticed an unrelated issue with the usage of > > >>start_isolate_page_range. On error we set the migrate type to > > >>MIGRATE_MOVABLE. > > > > > >Why that should be a problem? I think it is perfectly OK to have > > >MIGRATE_MOVABLE pageblocks inside kernel zones. > > > > > > > we can pick pages with migrate type movable and if we fail to isolate won't > > we set the migrate type of that pages to MOVABLE ? > > I do not see an immediate problem. GFP_KERNEL allocations can fallback > to movable migrate pageblocks AFAIR. But I am not very much familiar > with migratetypes. Vlastimil, could you have a look please? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
