On Tue, Apr 02, 2019 at 08:04:00AM -0700, Alexander Duyck wrote: > Basically what we would be doing is providing a means for > incrementally transitioning the buddy memory into the idle/offline > state to reduce guest memory overhead. It would require one function > that would walk the free page lists and pluck out pages that don't > have the "Offline" page type set, I think we will need an interface that gets an offline page and returns the next online free page. If we restart the list walk each time we can't guarantee progress. > a one-line change to the logic for > allocating a page as we would need to clear that extra bit of state, > and optionally some bits for how to handle the merge of two "Offline" > pages in the buddy allocator (required for lower order support). It > solves most of the guest side issues with the free page hinting in > that trying to do it via the arch_free_page path is problematic at > best since it was designed for a synchronous setup, not an > asynchronous one. -- MST
