LinearMeasurement slow on GPU

[cynddl]

Instantiating a LinearMeasurement object appears to be very slow on GPU:

https://github.com/ryan112358/private-pgm/blob/57554e604733a52f6dd217bd67feef0aa7a7435b/src/mbi/marginal_loss.py#L74-L80

I tried removing the converter and the code seems to run fine, and actually faster. My guess is that many calls to send data in advance to the GPU memory are not efficient at all.

[ryan112358]

Interesting, can you send a minimum example that demonstrates this behavior? It seems surprising that this would be the bottleneck compared to fitting the model or other parts of the code, but maybe depends on your use case