Add an option to disable CUDA constant memory dispatch - #9352
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Signed-off-by: Namjae Choi <Namjae.Choi@inl.gov>
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This PR adds a compile option
Kokkos_ENABLE_IMPL_CUDA_CONSTANT_MEMORYwhich can be used to optionally disable explicit constant memory dispatches for CUDA. Because of the constant memory buffer definition, it is currently required to set the RDC option consistently across all the downstream packages. If an application that wants to use RDC acquires Kokkos through one of its upstream packages, and if the package has its own Kokkos codes not using RDC, meeting this requirement becomes really painful. Combined with #9346, if a user sets this option toOFF, the user can use Kokkos as a fully self-contained library.As constant memory dispatch was replaced by
__grid_constant__kernel argument annotation (even though #9133 mentioned that it sometimes doesn't provide equivalent performance), and using constant memory should now be explicitly requested, those who didn't see performance hit and are not interested in explicitly using it may consider disabling it.