On 9/15/20 7:32 AM, Matthew Wilcox wrote: > On Tue, Sep 15, 2020 at 08:59:23PM +0800, Muchun Song wrote: >> This patch series will free some vmemmap pages(struct page structures) >> associated with each hugetlbpage when preallocated to save memory. > It would be lovely to be able to do this. Unfortunately, it's completely > impossible right now. Consider, for example, get_user_pages() called > on the fifth page of a hugetlb page. Yeah, exactly. Does this series survive the in-kernel selftests/? If so, sounds like we need to add a new selftest.