On Tue, Nov 16, 2021 at 08:25:33PM +0100, Drew DeVault wrote: > On Tue Nov 16, 2021 at 8:21 PM CET, Vito Caputo wrote: > > Considering a single fullscreen 32bpp 4K-resolution framebuffer is > > ~32MiB, I'm not convinced this is really correct in nearly 2022. > > Can you name a practical use-case where you'll be doing I/O with > uncompressed 4K framebuffers? The kind of I/O which is supported by > io_uring, to be specific, not, say, handing it off to libdrm. Obviously video/image editing software tends to operate on raw frames, and sometimes even persists them via filesystems. I haven't given it a lot of thought, but a framebuffer is a commonly used unit of memory allocation in code run on the CPU I've written over the years. Being able to pin those for something like io_uring (or some other DMA-possible interface) seems like an obvious memory-hungry thing to consider here if we're talking default upper bounds. Regards, Vito Caputo
