On Wed, Nov 18, 2020 at 3:45 AM Oscar Salvador <osalvador@xxxxxxx> wrote: > > On 2020-11-17 17:29, Muchun Song wrote: > > Now for the 2MB HugrTLB page, we only free 6 vmemmap pages. > > But your words woke me up. Maybe we really can free 7 vmemmap > > pages. In this case, we can see 8 of the 512 struct page structures > > has beed set PG_head flag. If we can adjust compound_head() > > slightly and make compound_head() return the real head struct > > page when the parameter is the tail struct page but with PG_head > > flag set. I will start an investigation and a test. > > I would not overcomplicate things at this stage, but rather keep it > simple as the code is already tricky enough(without counting the LOC > thatvit adds). > We can always build on top later on in order to improve things. I think that this improvement can be a separate patch. In this case, it can make the code evolution route clearer. Thanks. > > -- > Oscar Salvador > SUSE L3 -- Yours, Muchun
