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. -- Michal Hocko SUSE Labs
