On 10/24/2018 07:28 PM, Michal Hocko wrote: > On Wed 24-10-18 15:56:39, Michal Hocko wrote: >> On Tue 23-10-18 18:31:59, Anshuman Khandual wrote: >>> Architectures like arm64 have HugeTLB page sizes which are different than >>> generic sizes at PMD, PUD, PGD level and implemented via contiguous bits. >>> At present these special size HugeTLB pages cannot be identified through >>> macros like (PMD|PUD|PGDIR)_SHIFT and hence chosen not be migrated. >>> >>> Enabling migration support for these special HugeTLB page sizes along with >>> the generic ones (PMD|PUD|PGD) would require identifying all of them on a >>> given platform. A platform specific hook can precisely enumerate all huge >>> page sizes supported for migration. Instead of comparing against standard >>> huge page orders let hugetlb_migration_support() function call a platform >>> hook arch_hugetlb_migration_support(). Default definition for the platform >>> hook maintains existing semantics which checks standard huge page order. >>> But an architecture can choose to override the default and provide support >>> for a comprehensive set of huge page sizes. >>> >>> Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> >>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> >> >> Acked-by: Michal Hocko <mhocko@xxxxxxx> > > fat fingers here, should be mhocko@xxxxxxxx of course. Sure no problems. As we had discussed earlier and agreed to keep the previous patch "mm/hugetlb: Enable PUD level huge page migration" separate and not fold into this one, I will assume your ACK on it as well unless your disagree.
