pub const RDRAM_PAGE: usize = 4096;Expand description
Granularity of the RDRAM dirty-page map, in bytes.
4 KiB gives 2,048 pages for 8 MiB of RDRAM — a 2 KiB flag array, L1-resident,
so the once-a-frame scan is free. Finer pages would send less redundant data
but grow the scan; coarser would send more. Not tuned: 4 KiB is also the
alignment VK_EXT_external_memory_host wants, so the two agree by
construction rather than by coincidence.