[Feature Request] Add equivalent of cudaDeviceSynchronize()

[jbrodman]

Many applications written in CUDA rely on the whole device synchronization behavior of cudaDeviceSynchronize().
Trying to migrate applications that use this to SYCL, for example, is not really possible.

Question: Why does this need to be in L0? Why can't you solve it at a higher level?
Answer: The higher level layer may not have 100% visibility over how level zero is being used. If the L0 plugin in DPC++ tried to add something like this - programs may have incorrect behavior if the user application ALSO uses L0 directly - the plugin has no knowledge of any queues created in the user application or libaries.

[jandres742]

I dont see a problem adding this. cudaDeviceSynchronize "Blocks until the device has completed all preceding requested tasks." https://docs.nvidia.com/cuda/cuda-runtime-api/group__CUDART__DEVICE.html#group__CUDART__DEVICE_1g10e20b05a95f638a4071a655503df25d so it means we would just wait all task, submitted to all engines, to complete.

@jbrodman:

does it need to be per context or for all contexts running in the device? CUDA is just void, so I guess is the latter for them.

[jandres742]

BTW: @jbrodman this is the repo for the loader. Please open it in the repo for the spec in level-zero

[eero-t]

@jbrodman If you added ticket to spec repo, could you close this one? (link to that spec bug you filed would be nice too)