I'm pretty sure we're still re-inventing, though it's the CPU's turn to gain some of the complexity of the graphics engine.
Paul On Sun, Aug 22, 2021, 12:05 PM Bakul Shah <[email protected]> wrote: > Thanks. Looks like Sutherland's "Wheel of Reincarnation > <https://www2.cs.arizona.edu/~cscheid/reading/myer-sutherland-design-of-display-processors.pdf>" > has not only stopped but exploded :-) Or stopped being applicable. > > -- Bakul > > On Aug 22, 2021, at 9:23 AM, Paul Lalonde <[email protected]> > wrote: > > It got complicated because there's no stable interface or ISA. The > hardware evolved from fixed-function to programmable in a commercial > environment where the only meaningful measure was raw performance per > dollar at many price points. Every year the hardware spins and becomes > more performant, usually faster than Moore's law. With 3D APIs hiding the > hardware details there is no pressure to make the hardware interface > uniform, pretty, or neat. And with the need for performance there are > dozens of fixed function units that effectively need their own sub-drivers > while coordinating at high performance with the other units. > The system diagrams for GPUs look complex, but they are radical > simplifications of what's really on the inside. > > Intel really pioneered the open driver stacks, but performance generally > wasn't there. That might be changing now, but I don't know if their > recently announced discrete product line will be driver-compatible. > > Paul > > > On Sun, Aug 22, 2021 at 8:48 AM Bakul Shah <[email protected]> wrote: > >> The FreeBSD amdgpu.ko is over 3Mbytes of compiled code. Not counting the >> "firmware" that gets loaded on the GPU board. drm/amd/amdgpu has 200K+ >> lines of source code. drm/amd over 2M lines of code. Intel's i915 seems to >> be about 1/10th the amd size. AIUI, this is linux GPU driver code, more or >> less unchanged (FreeBSD has shim code to use it). How did the interface to >> an SIMD processor get so complicated? >> >> On Aug 22, 2021, at 6:44 AM, Paul Lalonde <[email protected]> >> wrote: >> >> I'd love to see GPU support for Plan9. This discussion falls right into >> my professional capacity. I'll say that people generally *grossly* >> underestimate the complexity of a modern GPU and of its supporting software >> stack. The GPU driver is effectively a second operating system with shared >> memory and DMA interfaces to the host. Even bringing up a modern GPU for >> just compute tasks is a very large endeavour. >> >> That being said, if you want real hardware support, the best place to >> start is currently AMD's open-source stack. Ignoring the Vulkan bit, >> understanding their platform abstraction layer (PAL) and shader ISA ( >> https://developer.amd.com/wp-content/resources/Vega_Shader_ISA_28July2017.pdf) >> is the base. The lower hardware levels are reasonably well-described in >> linux's libdrm and its AMD support in amdgpu. >> >> Opinions on how to bring this to Plan9? I don't really have any - it's a >> huge pile of work with minimal benefit. If you're looking for lightweight >> graphics, WebGL is a doable path, and almost certainly the right way to >> experiment with Plan9-like interfaces to graphics hardware. >> >> Paul >> >> >> >> On Sun, Aug 22, 2021 at 5:30 AM sirjofri <[email protected]> >> wrote: >> >>> >>> 22.08.2021 14:10:20 Stuart Morrow <[email protected]>: >>> > Also: >>> >> people have discussed that for years >>> > >>> > They have? I mean I might have seen occasionally someone vaguely >>> > going "some sort of GPU support would be cool to have". That isn't >>> > discussion. >>> >>> I've even heard of someone actually making GPU stuff work on plan 9. >>> I've >>> only heard from their partner, who made a cute glenda thing on a piece >>> of >>> cloth. I chatted with her a little and told her she should encourage her >>> partner for some discussion about this in our channels. It looked like >>> it's some academic work, but I don't know any details about it. >>> >>> Worst case, someone already has a proper and good GPU implementation for >>> Plan 9 and nobody knows about it. >>> >>> sirjofri >>> >>> Btw if the said person reads this: it would be nice to learn some >>> details. >> >> >> >> -- Bakul >> >> > *9fans <https://9fans.topicbox.com/latest>* / 9fans / see discussions > <https://9fans.topicbox.com/groups/9fans> + participants > <https://9fans.topicbox.com/groups/9fans/members> + delivery options > <https://9fans.topicbox.com/groups/9fans/subscription> Permalink > <https://9fans.topicbox.com/groups/9fans/Tad29bfc223dc4fbe-M69dfd52c6b6d85727b06d9dc> > ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tad29bfc223dc4fbe-M6309d0d2644e0651e74b9901 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
