Am 2020-04-20 um 1:44 p.m. schrieb Jacob Pan: >> The bottom line is, when you allocate a PASID for a context, you want >> to know how small it needs to be for all the devices that want to use >> it. If you make it too big, some device will not be able to use it. >> If you make it too small, you waste precious PASIDs that could be >> used for other contexts that need them. >> > So for AMD, system-wide PASID allocation works with the > restriction/optimization above? > Yes for KFD. On multi-GPU systems we allocate one PASID for the whole process and use it on all GPUs.
For AMDGPU graphics contexts, we allocate one PASID for each per-GPU context. But they're allocated from a single global PASID namespace managed by the AMDGPU driver and shared with KFD. So we're wasting PASIDs here, but we are compatible with a single system-wide PASID namespace. Regards, Felix
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