On Wed 17-04-19 21:15:41, Yang Shi wrote: > Hi folks, > > > I noticed that there might be new THP allocation in NUMA fault migration > path (migrate_misplaced_transhuge_page()) even when THP is disabled (set to > "never"). When THP is set to "never", there should be not any new THP > allocation, but the migration path is kind of special. So I'm not quite sure > if this is the expected behavior or not? > > > And, it looks this allocation disregards defrag setting too, is this > expected behavior too?H
Could you point to the specific code? But in general the miTgration path should allocate the memory matching the migration origin. If the origin was a THP then I find it quite natural if the target was a huge page as well. How hard the allocation should try is another question and I suspect we do want to obedy the defrag setting. -- Michal Hocko SUSE Labs
