4 ms·
So memory and I/O won't be on separate busses anymore? Will all CXL devices--formerly known as PCIe--be memory mapped now? Will IOMMU as a thing separate from
by tenebrisalietum 4y ago
So memory and I/O won't be on separate busses anymore? Will all CXL devices--formerly known as PCIe--be memory mapped now? Will IOMMU as a thing separate from MMU no longer need to be a thing?
- solarmist 4y agoThank you! Nowhere in the article do they tell you what CXL is!
- rbanffy 4y agoThis is a sin this website often commits. They just assume we know what they are talking about and they sometimes talk about the most esoteric tech we muggles never get to see.
- pclmulqdq 4y agoPCIe devices are memory mapped in most systems now. The IOMMU and the MMU are basically the same thing, but there are separate ones because the IOMMU has to handle multiple "bus masters" - the IOMMU's main job now is to protect memory from transfers initiated by malicious accelerators on the PCIe bus. The MMU is separate to prevent contention. The fiction of separate I/O and memory space is another abstraction that carries over from the 80's.
- rbanffy 4y agoIt's kind of fun that my first personal computer, the Apple II, used memory-mapped IO (because the 6502 was designed to be cheap, but still). :-)