Longhorn / is on Nostr

Kernel/hypervisor engineer, Amazon EC2. 

Blog: https://threedots.ovh/blog/
Twitter: https://twitter.com/never_released

Last Notes

2024-06-02 20:16:22

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oh, and as a related reminder, NV GPUs have no blockers on apple silicon macs when running Linux.
Apart from that Vulkan quirk, SW issues with PCIe non-mappable as normal NC don't cause issues on NVIDIA hw for those systems.

2024-06-02 20:16:22

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2024-06-02 20:13:50

gathered from x.com:
nvidia actually exposes a GPU upload heap (mapped BAR to user-mode) in Vulkan on Ampere Altra in their drivers.
This caused app breakage for Tellusim as Ampere Altra forces mapping BARs as device mem, instead of normal NC, for things to work properly. Device mem doesn't allow unaligned accesses.
It's a quirk that Apple Silicon Macs also have, and I'm tempted to say that perhaps NV should just not expose a GPU upload heap on Altra. After all, D3D12 didn't need it for ages.

2024-06-02 20:13:50