CALL.ABS.NOINC instruction in SASS

I’ve put error check for all CUDA calls and found that the program failed at the first CUDA call, see below:
cudaCheck(cudaMallocHost(&modulesInGPU, sizeof(SDL::modules)));
cudaErrorUnknown: unknown error

If we use cuda-memcheck, the program further returned error 999, e.g., Program hit cudaErrorUnknown (error 999) due to “unknown error” on CUDA API call to cudaHostAlloc.

The error is gone if we 1) remove launch_bound(512, 2) or 2) change the launch bound parameters to 256, 2.

I am unable to connect the dots at this point. I cannot recall encountering cudaErrorUnkown in more than a dozen years of CUDA programming.

What CUDA version is this, and what is the driver version? What GPU are you running on and for which architecture are you compiling the code? Can you post a minimal reproducer code (a small program others can cut & paste, compile, and run) that demonstrates the issue?

A general approach to weird error scenarios is to update to the latest CUDA version and driver package to make sure one is not exposed to bugs that are known and fixed. Then double check that the target architecture(s) specified at compile time covers the GPU(s) one intends to run on, because the compiler default for the architecture rarely matches one’s actual requirements and one would want to eliminate possible issues that might arise from JIT compilation.