On 03/02/21 14:52, David Hildenbrand wrote:
However, note that the TDP MMU does not need an rmap at all. Since that
one is getting ready to become the default, the benefits of working on
the rmap would be quite small and only affect nested virtualization.
Right, but we currently always have to allocate it.
8 bytes per 4k page, 8 bytes per 2M page, 8 bytes per 1G page.
The 4k part alone is 0.2% of the memblock size.
For a 1 TB memslot we might "waste" > 2 GB on rmap arrays.
(that's why I am asking :) )
Yes, we're in violent agreement. :) I mean that the simplest solution
would be to allocate it lazily when building a non-TDP root.
Paolo
