While I've been writing CUDA kernels for a while now, I've not used dynamic parallelism (DP) yet. I've come up against a task for which I think it might fit; however, the way I would like to be able to use DP is:
If a block figures out it needs more threads to complete its work, it spawns them; it imparts to its spawned threads "what it knows" - essentially, the contents of its shared memory, which each block of spawned threads get a copy of in its own shared memory ; the threads use what their parent thread "knew" to figure out what they need to continue doing, and do it.
AFAICT, though, this "inheritance" of shared memory does not happen. Is global memory (and constant memory via kernel arguments) the only way the "parent" DP kernel block can impart information to its "child" blocks?
There is no mechanism of the type you are envisaging. A parent thread cannot share either its local memory or its block's shared memory with a child kernel launched via dynamic parallelism. The only options are to use global or dynamically allocated heap memory when it is necessary for a parent thread to pass transient data to a child kernel.