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. I've spent a lot of time thinking about this, and there's a lot of work that needs to happen before we can do this, mostly in device drivers. Do you want to help? It's a multi-year project.