On Wed, 22 Jun 2011 15:39:23 +0200, Arnd Bergmann arnd@arndb.de wrote:
Why that? I would expect you can do the same that hugepages (used to) do and just attempt high-order allocations. If they succeed, you can add them as a CMA region and free them again, into the movable set of pages, otherwise you just fail the request from user space when the memory is already fragmented.
Problem with that is that CMA needs to have whole pageblocks allocated and buddy can allocate at most half a pageblock.