[lhl]

In Linux, you can allocate as much as you want with `ttm`:

In 4K pages for example:

    options ttm pages_limit=31457280
    options ttm page_pool_size=15728640

This will allow up to 120GB to be allocated and pre-allocate 60GB (you could preallocate none or all depending on your needs and fragmentation size. I believe `amdgpu.vm_fragment_size=9` (2MiB) is optimal.