On Wed 15-01-20 07:35:45, Qian Cai wrote: > > > > On Jan 15, 2020, at 4:22 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > > > Is this correct? CMA pages cannot be comound? > > I never saw a CMA page also a compound page. Also, in > alloc_contig_range(), it calls migrate_pages()—> > unmap_and_move_huge_page() which will free the old huge page, so I > think that will clear pageCompound. This sounds like the implementation detail. I do not think you want to depend on that. Anyway, see my other response. If you rebase on top of Vlastimil's patch you do not really have to care. -- Michal Hocko SUSE Labs
