The answer is that it works pretty similarly, but GPUs usually do this in specialized hardware whereas mmap'ing of files for DMA-style access is implemented mos

The answer is that it works pretty similarly, but GPUs usually do this in specialized hardware whereas mmap'ing of files for DMA-style access is implemented mostly in software. https://insujang.github.io/2017-04-27/gpu-architecture-overview https://insujang.github.io/2017-04-27/gpu-architecture-overv... has a pretty good visual of what's doing what for GPU DMA. You can imagine much of what happens here is almost pure software for mmap'd files.