On Wed, Jan 20, 2021 at 01:48:05PM -0800, Mike Kravetz wrote: > >> This comment addresses both this patch and the next one. > >> > >> Instead of putting the SetHPageMigratable flag spread over the > >> allocation paths, would it make more sense to place it in > >> alloc_huge_page before returning the page? > >> Then we could opencode SetHPageMigratableIfSupported right there. > > > > and in putback_active_hugepage. > > > Hi Oscar, > > In Muchun's series of hugetlb bug fixes, Michal asked the same question. > > https://lore.kernel.org/linux-mm/7e69a55c-d501-6b42-8225-a677f09fb829@xxxxxxxxxx/ > > The 'short answer' is that the this would allow a page to be migrated > after allocation but before the page fault code adds it to the page > cache or page tables. This actually caused bugs in the past. Oh, I see. I jumped late into that patchset so I missed some early messages. Thanks for explaining this again. -- Oscar Salvador SUSE L3
