One other thought: If you want to improve the behavior for large scale objects allocated through kmalloc/kmemcache then we would certainly be glad to entertain those ideas. F.e. you could optimize the allcations > 2x PAGE_SIZE so that they do not allocate powers of two pages. It would be relatively easy to make kmalloc_large round the allocation to the next page size and then allocate N consecutive pages via alloc_pages_exact() and free the remainder unused pages or some such thing.
