Tips

This section contains some tips on what to do and what not to do using the project.

GPU kernels

• Generally don't derive Debug for structs in GPU crates. The codegen currently does not do much global DCE (dead code elimination) so debug can really slow down compile times and make the PTX gigantic. This will get much better in the future but currently it will cause some undesirable effects.

• Don't use recursion, CUDA allows it but threads have very limited stacks (local memory) and stack overflows yield confusing InvalidAddress errors. If you are getting such an error, run the executable in cuda-memcheck, it should yield a write failure to Local memory at an address of about 16mb. You can also put the ptx file through cuobjdump and it should yield ptxas warnings for functions without a statically known stack usage.