On Fri 18-10-19 10:38:21, David Hildenbrand wrote: > On 18.10.19 10:24, Michal Hocko wrote: > > On Fri 18-10-19 10:13:36, David Hildenbrand wrote: > > [...] > > > However, if the compound page spans multiple pageblocks > > > > Although hugetlb pages spanning pageblocks are possible this shouldn't > > matter in__test_page_isolated_in_pageblock because this function doesn't > > really operate on pageblocks as the name suggests. It is simply > > traversing all valid RAM ranges (see walk_system_ram_range). > > As long as the hugepages don't span memory blocks/sections, you are right. I > have no experience with gigantic pages in this regard. They can clearly span sections (1GB is larger than 128MB). Why do you think it matters actually? walk_system_ram_range walks RAM ranges and no allocation should span holes in RAM right? -- Michal Hocko SUSE Labs